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Other Stuff => Archived Circles => Hypex Owners Circle => Topic started by: revelinhifi on 7 Aug 2013, 10:17 pm

Title: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 7 Aug 2013, 10:17 pm
Hello ncore owners,

Has anyone tried the Ric Shultz WIMA capacitor modification, (replacing a single stock wima cap .68mf with two .33mf polypropylene)

http://www.audiocircle.com/index.php?topic=110782.0
The post reports better sound after swapping out the stock cap's "Way more ambience, clarity and reality"

I have been unable to establish contact with Ric, no replies to emails. Therefore I ask any forum members have they any personal experience or knowledge of anyone having done this?

Absolutely no offence intended to the wonderful designer Bruno or anyone else wishing to leave their NC400 stock standard. Purely a curiosity factor for myself and the possibility of trying the sound if it seems worthwhile. I'm not a tall troubled by replacing parts at this level of difficulty, however I'm not at all willing to experiment without previous knowledge that this is a worthwhile exercise.

I'm interested in the fact that the NC1200 uses polypropylene caps

My current system is 4XNC400. Each pair of NC400 is feed by a single SMPS600. A pair of amps feeds by AMPed Speaker

Appreciate your responses

Thanks
John
 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 7 Aug 2013, 10:22 pm
however I'm not at all willing to experiment without previous knowledge that this is a worthwhile exercise.
Since it would not be based on any science I think you would need to try for yourself.  Subjective is just that.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 7 Aug 2013, 10:27 pm
Hello jtwrace,

yes loud and clear, and I would agree that's the way to go. Although I would appreciate any comments experiences of anyone having already done the same.

Regards
John
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 15 Aug 2013, 05:08 am
"I'm interested in the fact that the NC1200 uses polypropylene caps"

I do not believe the above is correct.  I know that Ric did speculate about this in his posts, but in every picture of the NC-1200 which I have seen the caps appear to be polyester Wimas.
The problem with the mod, is that the caps do not really fit, and considering the emphasis Bruno puts on keeping loop areas compact, I really doubt changing  the caps to ones with much greater loop areas are really going to have good results. 
What I do find interesting is that in the description of the Mola Mola amps (which, apparently do not use the stock OE NC-1200, but a variant of it, with a separate board for the input stage) the company mentions a special monolithic cap which is used...
On the one hand Bruno dismisses the idea that the NC-400's stock caps are at all a compromise (see DIYaudio thread for his opinion), but on the other hand he seems to feel it is worth it to produce and use a special cap for the Mola Mola...  Hmmm.
Wish Hypex had chosen to have a custom film PP cap made for the NC-400, to me polyester seems a little "ordinary" for the job at hand.  It seems a custom 2 uF cap is in order... to replace all three of the .68 uF Wima polyesters.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 15 Aug 2013, 06:42 am
Wima polyester and polyprop caps look identical.  The pic of the 1200 modules on the six moons review of the Atsah shows 6 caps per channel.  That would make them .33uf each.  This is the largest value you can get the polyprop caps in.  So, are they .33 polyprops or polyesters?  In any case they have steel leads are are not marked for outside foil so they are not necessarily in the right direction.  Loop area?  The modded caps are mounted one third inch above the board.   You think you can hear that?  Changing one .68 polyester to two .33 modded and properly marked Wima polyprops on the NC400 simply sounded better.  I trust my ears.

It will be interesting to see if the Mola Molas sound better than the Atsah or Merrills.  Right now I am looking at the Job 225 amp (will be listening and modding one in the next week or so).  It may be this years giant killer.   What, Ncore already outdated?  We shall see.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 16 Aug 2013, 12:45 am
There's a man on here that modifies WIMA's (http://www.tweakaudio.com/EVS-2/Modded_Wima_Caps.html). They use to be perhaps world class, then they stopped putting copper leads on them. They haven't been the same since, is the story. He opens their ends and replaces the leads with copper. The results are probably all you'd ever ask for, no need to "swap" to another cap for the situation. But I haven't used them. I think it'd explain the change from WIMA's prominence.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: gstew on 18 Aug 2013, 12:39 am
Am I the only one that finds it humorous that the previous post references "...a man on here that modifies WIMAs" and that the post just above it is by that man?

8)

Then, spending a few minutes looking through the easily-findable web-photos along with the datasheet and manual for the NC1200, one sees that its output filter has positions for three sets of two caps... and in most pictures (including on Hypex's info), you see both positions filled. And if you zoom the pictures in Hypex's info, you see the caps are .33uf 100v, supporting the suggestions that they are polyprops. Only the pics in the 6Moons Industry Feature announcing the NCore amps shows one cap in each position. And if they are .68 as one might suppose, then I'd agree with Ric that in this instance, they were mylar as Wima does not list a .68uf polyprop.

This plus the comments above lead me to a few questions:


1. Why is there any question about the goodness of polyprop caps versus mylar? I thought this was all settled in the early '80s with the Jung/Marsh article on 'Picking Capacitors' in the now-defunct Audio magazine and tons of related articles since.


2. I get the importance of tight loops in digital circuits (tho I am not an EE). Why is Ric's stacking of two .33 polyprops significantly worse than using two side-by-side as in the published photos of the NC1200?


3. Has anyone considered or better-yet tried some of the SMD PPS capacitors available in place of the Wima's?  Panasonic lists a .22uf 100v PPS available at Mouser. I've read varying accounts of the 'goodness' of PPS versus polyprops and polystyrenes, but they sound to be in the same class. At  7.1mm L x 6.3mm W x 4.8mm H, they could be soldered together into three stacks of about the same footprint as the existing mylar Wimas, cobbled into the circuit with some add-on leads similar to what Ric uses to modify the Wimas, and provide about the same capacitance and loop area with a better dialectric. The only question I have is outer foil directionality... I believe these are stacked foil, not wound like the standard Wimas. Do stacked foil caps have an outer foil?


4. Barrows, my thoughts looking as the components around the output filter top and bottom are that the three .68uf caps are not in parallel to make a single 2uf cap, but that they are seperate legs of a more complex filter. Have you traced the circuit and confirmed that they are used as a single 2uf-value cap?


Greg in Mississippi


P.S. Reading the NC1200 manual and datasheet was very instructive. First, the little circuit boards sticking up that I assumed were add-on input circuits turn out to be the regulators. Second, it appears to come with an input circuit (buffer) built-in, but it can be easily bypassed with soldered-jumpers... that's likely how one adds a different front-end circuit.

Pity, they don't sell this one to us DIY'ers! It'd be a lot of fun!!!

And does anyone who read the super-long NCore threads here and on DIY Audio remember if there are comments about the NC400 having high-quality regulation built-in for the input stages? If the NC400 does not, this is likely another thing that helps explain the sonic differences reported between the NC400 and the NC1200
implementations.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 18 Aug 2013, 11:32 am
if "there is no question about the goodness of polyprop caps versus mylar" i wonder what keeps Bruno from using polyprops in the first place?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 18 Aug 2013, 03:40 pm
Wima polyester and polyprop caps look identical.  The pic of the 1200 modules on the six moons review of the Atsah shows 6 caps per channel.  That would make them .33uf each.  This is the largest value you can get the polyprop caps in.  So, are they .33 polyprops or polyesters?  In any case they have steel leads are are not marked for outside foil so they are not necessarily in the right direction.  Loop area?  The modded caps are mounted one third inch above the board.   You think you can hear that?  Changing one .68 polyester to two .33 modded and properly marked Wima polyprops on the NC400 simply sounded better.  I trust my ears.

It will be interesting to see if the Mola Molas sound better than the Atsah or Merrills.  Right now I am looking at the Job 225 amp (will be listening and modding one in the next week or so).  It may be this years giant killer.   What, Ncore already outdated?  We shall see.

Ric, I suggest you do a little more research.  Polyester Wimas have silver printing on them, and the polpropylene ones have black printing.  They do not have identical appearance.  They also have the model numbers marked.  Not that I am suggesting that polyester is good!  I am with you, I would much prefer a polypropylene cap, or better yet, polystyrene in the filter circuit.  But Bruno would probably suggest: "size matters".  RE: the loop area, Bruno has stated many times the critical nature of the loop areas, in MMs, on the Ncore modules.  I do not know if I could hear the difference or not, I have not tried, but it is just as likely that you hear differences caused by increased RF pick up as it is you hear a difference related to the cap change, or lead orientation.  Until you back up your mods with measurments on an AP 2, there is no confirmation that the amps are performing better, and the subjective change could, actually, be worse performance...  I am not saying that it is, just that there is no confirmation.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 18 Aug 2013, 03:55 pm
Greg:  Right on!  I think your suggestion regarding PPS caps is worth a try.  I have used some of those in mods to cheaper DACs, replacing SMD ceramic caps used in the analog filter with the PPS films with good results, but I have never compared the sound of PPS to polypros or polystyrenes, but they are compact and could be made to fit on the board very well.
I do not know that the 3 caps on the NC-400 are acting as one, tracking the traces on the board is not so easy, but next time I have one off of the heatsink I will take a look and see what I can determine.  I am just not sure how the LPF would be "more complex" than the simple LC I assume it is?  Do you have ideas about this?  Most class D amps where I have seen the schematic just show the LC, and the output of the NC-400 being single ended seems to support this, or maybe my thinking is all wrong here?  Please let me know what you think.
There are big technical differences in the Mola Mola versus the Atsash and Merrill.  Mola Mola uses a separate input board, with a discrete input stage, and the aforementioned monolithic caps in the output filter.  Merrill and Atsah just use a stock NC-1200 module with the OE IC opamp input stage.  I would expect differences in sonics for sure.  The Audience NC-1200 based amp should also sound different, with transformer coupling and their own discrete input stage.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 18 Aug 2013, 04:11 pm
Greg:

"2. I get the importance of tight loops in digital circuits (tho I am not an EE). Why is Ric's stacking of two .33 polyprops significantly worse than using two side-by-side as in the published photos of the NC1200?"

We are talking about the NC-400 here, Ric's mod with the stacked caps doubles the lead length of that cap.  Considering how much Bruno stresses the importance of PCB layout and lead length, critical to fractions of a mm, that additional lead length bothers me.  Without doing some precise measurements it is impossible to know if it causes a problem for the module.

RE differences between NC-400 and NC-1200.  Both have the discrete regulators (based on the Hypex HxR regs) for powering the input stage.  But the NC-400 uses a discrete input circuit as well, and the NC-1200 uses an IC opamp for the input circuit.  Hence the Mola Mola amp using a separate, discrete, input circuit, and Audience also using a discrete input circuit of their own design.  Considering how accurate the Ncore output stage is, I suspect these different input circuits would be responsible for much of the difference in sonics of these amps.  Even in well designed class A/B amps, the input gain stage is often what defines much of an amplifiers sonic character.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: gstew on 18 Aug 2013, 05:20 pm
if "there is no question about the goodness of polyprop caps versus mylar" i wonder what keeps Bruno from using polyprops in the first place?

Pure speculation from me is the need to have a small, good-quality cap that is available and can be easily accomodated in the manufacturing process. Modified or stacked SMD caps just don't work when you are doing pick and place. And AFAIK, there are not any other comparible quality & sized caps available in the marketplace. My guess is the Wima mylar cap worked from these perspectives and that the sound quality hit is not sufficiently large to worry about when there are SO many other things that can impact system sound quality.



Ric, I suggest you do a little more research.  Polyester Wimas have silver printing on them, and the polpropylene ones have black printing.  They do not have identical appearance.  They also have the model numbers marked.  Not that I am suggesting that polyester is good!<SNIP>

Thanks, I've seen that, but really haven't noticed it. That means that the caps shown on the NC1200 in the datasheet and manual are .33 100v Wima polyester.
Why two polyester where two polyprops could fit, I have no clue!



Greg:  Right on!  I think your suggestion regarding PPS caps is worth a try.  I have used some of those in mods to cheaper DACs, replacing SMD ceramic caps used in the analog filter with the PPS films with good results, but I have never compared the sound of PPS to polypros or polystyrenes, but they are compact and could be made to fit on the board very well.
I do not know that the 3 caps on the NC-400 are acting as one, tracking the traces on the board is not so easy, but next time I have one off of the heatsink I will take a look and see what I can determine.  I am just not sure how the LPF would be "more complex" than the simple LC I assume it is?  Do you have ideas about this?  Most class D amps where I have seen the schematic just show the LC, and the output of the NC-400 being single ended seems to support this, or maybe my thinking is all wrong here?  Please let me know what you think.
<SNIP>


I've used SMD PPS caps to replace SMD ceramics too with good effect, along with use a local PS filters on the error amps of Dexa regulators I've modified.

I've also kept watch for others using them... some pictures I saw of an Ayre DAC seemed to show a number of SMD PPS caps around the digital circuits, as do the pictures I've seen of K&K Audio's RAKK DAC. AMR touts their use of SMD PPS caps in their literature. And in the DIY world, I currently use a small ES9022-based DAC card from EUVL on DIYAudio (that actually sounds much better than one would expect). One thing he does is to solder filtering caps right on the legs of the ES9022 chip. In his latest version, these are now SMD PPS.

On the output filter of the NC400, I had in mind diagrams I saw of the output filters used in B&O Icepower amps which show an LC and a Zobel. Download the datasheets for the 1000asp and 200asc to see what I  mean. Also, I was looking at a picture from SerengetiPlains' NCore mods thread awhile back. He posted a number of closeups of the backside of the NC400 board and one shows the components around the filter caps, of which there are a few R's and C's. I've posted it here again for reference. But I have not traced it and cannot say what the filter is.



<SNIP>
We are talking about the NC-400 here, Ric's mod with the stacked caps doubles the lead length of that cap.  Considering how much Bruno stresses the importance of PCB layout and lead length, critical to fractions of a mm, that additional lead length bothers me.  Without doing some precise measurements it is impossible to know if it causes a problem for the module.

RE differences between NC-400 and NC-1200.  Both have the discrete regulators (based on the Hypex HxR regs) for powering the input stage.  But the NC-400 uses a discrete input circuit as well, and the NC-1200 uses an IC opamp for the input circuit.  Hence the Mola Mola amp using a separate, discrete, input circuit, and Audience also using a discrete input circuit of their own design.  Considering how accurate the Ncore output stage is, I suspect these different input circuits would be responsible for much of the difference in sonics of these amps.  Even in well designed class A/B amps, the input gain stage is often what defines much of an amplifiers sonic character.

I too am curious if it causes problems and would love to see those tests, if they were ever done. OTOH, I have a lot of faith in Ric's abilities to identify and develop ways to build & modify EQ for better sound focusing on areas that seem un-important or counter-important to others, but in practice make significant differences. I have several pieces of gear build or modified by him and have never been disappointed... and when I've reverse-engineered his techniques and applied them to my own DIY efforts, I've also been happier than expected.

Good to know on the regulators on the NC400... I had a vague recollection they were there, but as you've noted in the past, it is hard to get information out of all of the data in the monster DIYAudio NCore thread.

And on the differences between the various incarnations of the NC1200, I really haven't paid much attention here as I'm never expecting to be buying one, given what they charge. I'm just happy I've gotten to the point of really liking the NC400's in my setup.

Greg in Mississippi


(http://www.audiocircle.com/image.php?id=85474)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 21 Aug 2013, 06:47 am
Thanks to those that responded to the question I asked.  :D

I will be modifying a pair of NC400 amps with a stacked pair of polypropylene .33mf =.66mf
I will be replacing the three polyester .68mf capacitors for a more life-like tone to the Ear

My current setup with the NC400
The four NC400 are located in a single aluminium container. Each pier of NC400’s is powered by a single SMPS600. This is bi-AMP arrangement to power a single speaker.

This is bit perfect setup for me to prove this mod stock polyester to polypropylene, test instrument the Ear (physical cap surface area after change twice the area though same PCB board placement of stock cap) emi I will listen out for it :thumb:

-Components-

PS Audio power plant 
PS Audio MK11 DAC with Ethernet Bridge
Software – Player - Jriver - driver bit perfect PS Audio WaveStream out on windows 8 CPU 3770k and 16 gigs ram CPU shows <1% utilisation streaming 24\96 bit album

Amplifier 4 X  NC400 bi-wire pair power speaker
Cables - silver
Cables - balanced
Speaker- Theophany Rhapsody

Thanks  :thumb:
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 29 Aug 2013, 08:02 am
If anyone is interested

Two of the four NC400 have been modified swapping out the .68mf polyester cap for .33mf staked polypropylene. One of the six caps pulled had steel leads.

They have not fully burned in yet, only two hours operation, from first switch on it was plainly evident the mod was successful sounding better to my ears.

I have lived with the 4 NC400 for about a year and very familiar with the tone. I wont go into a lot of detail other than the sound is greatly improved and well worth the effort of the mod. Big thanks to Ric Schultz at tweakaudio for the modified WIMA Caps.

The sound improvement was one I can reference to going from the mk1 digital to analogue board to the mk2 digital to analogue board in my PS Audio DAC those having done this will know exactly what I mean. In essence the NC400 is now more detailed and a greater sense of that's how that instrument sounds.

I will update as the caps burn in
First hour - power up and after some listening it was apparent to me that the mod sounded better than stock -
24 - hours in the sound is more open, WOW love the sound of the guitar and violin, there is an improved sound to the bass and vocal is more articulate
48 - many hours of listening now and these are my last words. The Polyester caps don't do the sound justice for the NC400. The polypropylene caps have resulted in a more articulate musical performance, the ambience is easy to connect with and I find myself tapping to the rhythm of the music. I do find it incredible there is more music to hear with this caps swap-out. If I ever get a chance I will get the amp measured to see if the specs have changed. My concerns the caps would have attracted noise was not to be the case the. the highs are significantly more detailed, vocals more etched and lifelike the bass has good weight but sounds more defined.  :thumb:

Changing out the .68mf polyester caps for .33mf stacked polypropylene has a sound difference way more significant than changing cables in your system.
 
I have not finished the job, this was initially to check the mod was good. Well it passed without any doubt.  I plan to mod the remaining two, at that time I will rotate each NC400 180 degrees shorten the wiring significantly. Another idea I will take the power loom and put this to the outside beneath the case and pop it through the case at each point connecting to the NC400 and SMPS600 respectively. I will shield the cable on the outside beneath the case. I will partition off the PSU from the NC400's as well

You may see I removed the Speaker post and replaced those with Silver wire contacting all four point beneath the PCB

If you have an NC400 and have not done this mod there are sound on your music files you are not hearing. I am familiar with my music and I am hearing musical sound not previously heard.     

You could say what a horrible job with the wiring and that it is, therefore it should be quite the antenna and radiator, hmm I'm not getting any audible noise but beautiful music.

I recommend the mod over the stock unit, however there is a little skill and patience. I wonder if the wiring tidy up will benefit the musical performance. The high frequency I like very much, cant wait for my other caps to arrive. Big thanks to the other forum member who shared his experience and knowledge - go Mississippi

waiting now for my other caps to arrive so I can do the final pair and go back to a bi-amped configuration :thumb:

Cheers
John
(http://www.audiocircle.com/image.php?id=86027)

(http://www.audiocircle.com/image.php?id=86028)
     
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 24 Sep 2013, 05:44 am
The last six pairs of caps have arrived they have been installed into the NC400. An initial listening session was completed to confirm the installation was successful in which it was.

I have not done all my wiring reconfigurations as mentioned in previous posts here, but the capacitors are Installed and the Speaker Posts Have Been Replaced for Direct Silver Wired wires.

The SQ of these amplifiers are significantly improved by these two modifications. In a nutshell the highs are significantly more extended the mid range is improved and the base has tighter control. I cannot detect any elements to the music heard which is not improved over the stock unit so I'm very positive about this modification that the sound produced by the NC400 is better than the stock unit.  If anyone has any interest, I will be happy to provide further feedback. Drop me a message and I will reply as soon as able.

I will post new pictures sometime in the near future. This will show four NC400 modified.

Regards John
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 26 Sep 2013, 10:21 am
All done now here is the 4 NC400 with the modified caps and the connecting power loom outside the case. At a latter time I may put in a wall inside the case and still to fashion a cover beneath the case to contain the power connecter cable. 

Oh yes, the SQ is way better than the stock unit, I'm confident to announce that fact here, there is no negatives heard the sound is better in all respect compared to the stock unit..


(http://www.audiocircle.com/image.php?id=87528)
 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 26 Sep 2013, 11:11 am
How they measure with the new caps?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 26 Sep 2013, 12:40 pm
How they measure with the new caps?

And, just out of curiosity, have you asked Bruno about his opinion on the mod?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 26 Sep 2013, 10:13 pm
Jtrace said: How they measure with the new caps? This is a good question I used the human EAR for the test and don’t have recorded results - just the knowledge and experience.

The un-modified unit was compared to the modified unit before completing all four. All I had to do was swap speakers between the amps.
No deficiency heard compared to the stock caps. The improvement is not minor but significant audible improvement.
Julf: No I have not asked Bruno; to ask that question you would want to be supported by measurements of the modified amp. And I did not set out to improve measurements, how can you if the stock unit measures near perfect.
The available space on the NC400 does not allow for polypropylene X 6 CAPs and only DIY can implement as I’ve done. The manufacturing process does not allow this type of implementation, it is non-standard and restricted to space, only accommodating the polyester caps.
I have implemented same capacitance, they should be very close in measurements - just different capacitor material and slightly bigger physical foot print.  Consider these facts below

1. All caps foil side facing ground
2. No steel lead caps

Power connector routed outside the case minimising RF and cause induction to sensitive wiring and components.
I can comment as I have done, because I have lived with my NC400 for over a year and know the sound they produce and compared the stock unit to the modified unit. I have taken time doing this and can say the stock unit is significantly down in SQ in comparison, nothing lost only gained. There is significant untapped performance in the NC400 for the human Ear to hear.

Regards
John
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Sep 2013, 10:45 pm
We don't really know if this is an improvement. All we know is that you prefer it. It is completely subjective.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 27 Sep 2013, 12:03 am
If you're interested in getting it measured and having the results posted I could probably make this happen for you. 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 27 Sep 2013, 12:06 am
We don't really know if this is an improvement. All we know is that you prefer it. It is completely subjective.

absolutely true however I know the results myself and wanted to share and if another person tries they will know the same and may want to share.

It is easy to revert back to the stock caps if I felt the change was negative, if you follow good procedures to replace the caps it is only time and skill which I had available. Minimum heat time to the PCB is essential

here is some of my process to remove caps and verify yourself if interested.

If the pneumatic solder sucker did not get all the solder out in one session for each cap I would wriggle the capacitor while putting heat on one leg at a time to remove the cap. my success rate with the pneumatic solder sucker two out of three caps, the remaining required some manual intervention.

Then to clean the hole I would get my 9 year old son to help, here I will explain that process = I would have my son hold and have ready the manual solder sucker pump on the upside of the board while I held the NC400 and applied heat to the lower side hole. this method cleaned the hole beautifully and quickly, very little heat time on the board.
 
Thanks
John
 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 27 Sep 2013, 12:17 am
Thanks JT for the offer

I am in New Zealand, and this is not very economical to take that action, also my listening enjoyment would be gone.

Its not that important to me the measurements though it interest me some. In the near future I could take my amp to a technician who could do the measurements and report back the results, - see if there is any deviation from stock.

A cannot promise a quick turn around on that, the driving passion to do that is not really there, only a small amount of interest in doing that, I'm thinking it will be very close or same to stock. And that is the small amount of interest which may drive me to verify this fact.

Thanks
John
 

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 27 Sep 2013, 10:29 am
The un-modified unit was compared to the modified unit before completing all four. All I had to do was swap speakers between the amps.

But you did the swapping yourself, so you knew which was which?

Quote
No I have not asked Bruno; to ask that question you would want to be supported by measurements of the modified amp.

I'm just curious if his reaction would have been "Ah yes, good idea, we did cut some corners there!" or "That is a really bad idea, because...".

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 27 Sep 2013, 11:11 am
I am in New Zealand, and this is not very economical to take that action, also my listening enjoyment would be gone.
Understood.  If anyone in the USA has done the same I'll extend it to you. 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 27 Sep 2013, 12:18 pm
But you did the swapping yourself, so you knew which was which?

I've done many changes over the years and had many components. you know when you get a better sounding product right?
I went from a MK1 PS Audio DAC to a MK11 the SQ was a good upgrade this change to the NC400 is easily as good a contribution to better SQ

I'm just curious if his reaction would have been "Ah yes, good idea, we did cut some corners there!" or "That is a really bad idea, because...".

Feel free to ask Bruno as I was saying there are manufacturing difficulties with implementing the polypropylene cap there is not enough space to accommodate 6 caps as a DIY there is the benefit of doing something non standard, it may measure the same perhaps but sound different to the EAR Hmm
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 27 Sep 2013, 12:21 pm
Understood.  If anyone in the USA has done the same I'll extend it to you.

I am hopeful someone may like to mod there NC400 and benefit from improved SQ  :D
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 27 Sep 2013, 01:01 pm
it may measure the same perhaps but sound different to the EAR Hmm

So what is your view - why would it sound different if there are no measurable differences?

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 27 Sep 2013, 09:01 pm
So what is your view - why would it sound different if there are no measurable differences?

Have you ever swapped out a standard fuse? one which was not reputed to be audiophile grade! I have, and there was an audible SQ improvement.

My back ground was in a technical field and I doubted the benefits of such a change as it did not add up for me, till one day I said to myself what is there to loose $100.00 as people were reporting through numerous accounts of the SQ improvement, I did this in my PS Audio DAC and heard the SQ improvement.

My view is different material can sound different and only our EAR is able to detect an audible change and the change is not measurable with the level of technology available today. i.e. Science needs to invent a new measuring tool - perhaps there is a measurement not yet known that can justify why there is a difference in sound. Our physics and science has not worked this yet to be discovered measurement out yet.  Hmm I especially enjoyed the America's cup "yachting' recently and the implementation and use of equipment enabling a significantly faster upwind than actual wind speed only recently this was achieved. The same elements have been there for how long. Now what is needed is some serious investment for a new tool that can match the Human EAR and measure why a material can sound different over another, though the measure the same with our limited understanding of physics we know today. There are laws not yet quantified.

I am thankful to some who try new things, that on the face of it should not make an audible SQ difference. So if it seems plausible and has some sense with the understanding I have and it lacks known science I'm a chap who is willing to give it a go - and let my EAR tell me if the SQ has improved. When it comes to this my passion for the hobby I love. I understand that all people are not the same in this respect and have doubts and are less willing to give things a try. I am an amateur radio operator and reasonably skilled at making these types of changes at the circuit board level. It is easy to go back though I have stated this won't be happening as the SQ is significantly improved over the stock unit with capacitor change. Last night I could describe the listening session as having a set of headphones on my head and in my own private world. I was listening at a reasonably low level due to the lateness and the ability for the NC400 to amplify as it don't was awesome it was never this good. The soundstage is so focused and clear and very musical.

So to sum up we don't have instruments available to day which can measure the difference we can hear with our ear yet we cannot make measurements to explain the difference in what we hear with our ear. There is lacking in a tool and a measurement, please find this tool and measurement to explain what we hear with our ear. When measuring different elements which measure the same with the physics we know.

So what is your view - why would it sound different if there are no measurable differences!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! type written through dragon dictating
 
 Thanks John
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 27 Sep 2013, 11:16 pm
Differences in sonic characteristics of polyester vs polypropylene capacitors of the same value are well documented: do you believe in using polyester caps for loudspeaker crossovers?  Also, these capacitors will measure differently, polypropylene is a lower loss dielectric.  Every cap is going to absorb some signal, and then release that energy as a time delayed signal, the less signal loss is, the less time smear will be audible.  If we had a "perfect" cap, none of this would matter, but components are never perfect.  The closer to perfect the cap becomes, the closer to transparent the filter circuit is.

What I do not understand is the reference to outer foil?  Wimas are stacked caps, they are not wound right?  So how is there an outer foil?

As to whether Hypex could use something "better" than the Wima polyester caps, that would probably require having a custom cap built, which would be possible, but raise prices.
I have noted before that Mola Mola states clearly that their amplifiers use, what sounds like, a custom "monolithic" capacitor for the output filter (as opposed to the film caps on the OEM NC-1200 modules).  So, it appears that Bruno does accept that their are different sonic signatures for different capacitor types.  To me, "monolithic" typically indicates a ceramic cap, which is odd, as most audio folks feel ceramic caps do not fair well for filtering analog signal paths, any ideas on what os going on with the Mola Mola amps?

Revel: thanks for great pictures of your mods!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 28 Sep 2013, 12:31 am
Thanks Barrows  :D

I was interested to provoke thought the fact is the SQ is better with another CAP same value though different construction and material. I am listening to better SQ :thumb:

apparently with an oscilloscope and a particular test the caps shows that there is an orientation and they are installed the same orientation in the NC400 also losing steel leads. Yes Hypex would need to find another cap if they wanted to change the tine of the current stock. Hypex went with the polyester and as a DIY, one can change those caps if they wish, having read other peoples results from having done it. if there was less conversation about this topic then less people would realise the potential and be able to enjoy more SQ from the NC400, I'm happy to make that known 

Cheers
John
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 28 Sep 2013, 02:24 pm
So what is your view - why would it sound different if there are no measurable differences

I can't think of any reason, so that is why I asked. I am not saying there can't be differences, but I would have to see verified results of a double-blind ABX before I would start to look for new ways to measure hitherto unmeasurable differences.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 29 Sep 2013, 07:59 pm
I can't think of any reason, so that is why I asked. I am not saying there can't be differences, but I would have to see verified results of a double-blind ABX before I would start to look for new ways to measure hitherto unmeasurable differences.

Julf, I think there are big problems with measuring time smear.  My suspicion is that many different things in the signal add different amounts, and different durations of time smear, these are subtle (at best) and they add up to the overall final result.  The history of audio is full of of examples of things which are believed to cause sonic problems, which no one realizes how to measure, then, when a way to measure the problem is found, the result often confirms what the listeners were hearing all along.  A more recent example of this is ESS and their attempts to improve DS modulator design, their engineers accepted that there were problems not shown in the traditional measurement set (caused by inter transient noise in the modulator).  They found a way to measure the problem, and then went back to the listening tests.  Their listeners could detect when turned on and off the "solution" used in their "hyper stream" modulator design.  So, here we have a group of engineers using a listening test to improve their DAC design, and then confirming these results through a new measurement protocol.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 30 Sep 2013, 09:41 am
Their listeners could detect when turned on and off the "solution" used in their "hyper stream" modulator design.

So it was a blind listening situation?

Quote
So, here we have a group of engineers using a listening test to improve their DAC design, and then confirming these results through a new measurement protocol.

Yes - and that is how engineering (and science in gereral) works. You make observations, you verify them, and based on that you develop more sophisticated models and measurement methods.

An essential part of that is *verifying* your observations. Among other things, it means ensuring the observations are not caused by other factors such as perception bias.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 1 Oct 2013, 06:46 am
You would have to have significant hearing loss at the higher audio frequencies not to be able to distinguish the stock unit from the modified NC400. The same goes for the midrange. I'm happy with the Bass as well there is good balance.

Ill say again as there has been lots said and it may have gotten lost - I had the NC400 for a year or more and I was very familiar with the sound signature. Also I was able to AB just by swapping the speaker leads overs. The input was not changed as the input was split feeding each amp pair.

The SQ improvement is not small like swapping a cable, now I said this was on par with going from a PS Audio Mk1 DAC board to a PS Audio MK11 DAC board, (search and read those reviews if you like) those who have done that will know the SQ difference I'm talking about. You don't need someone sitting next to you say did you hear that difference, because its that significant.

If you are an NC400 owner and you are wondering were the Highs and the Midrange is well its trapped - filtered in those polyester caps  :thumb: the polypropylene caps lets that sound out for sure :lol:

I've said enough now and wont repeat myself anymore, and will comment only when I have something else that is worth sharing that genuinely improves the music experience heard.

Enjoy the music I am :D

John

 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 1 Oct 2013, 08:41 am
So I guess that's a "no" then.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 1 Oct 2013, 08:57 am
Was not required, I am entirely confident in what I hear and know when SQ is improved.

NO other person was involved to give an AB comparison.

One thing I have not mentioned. The sound stage is more believable, improved focus on instruments. this is an interesting factor if something was less accurate there is a good chance imaging performance would suffer however this is improved over the stock NC400  :D   
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 2 Oct 2013, 02:25 am
Wima caps are not stacked foil.  The pics on the spec sheets make it look like they have stacked construction....not so.  They are wound just like any other cap.  So, the outside foil is very measureable and sonically important.

The difference between polyester and polyprop is only one reason why these make the sound better.  The ends are ground off and the steel leads are changed to 6N copper leads and then they are marked for outside foil and all caps put in the correct direction.  The stock polyester caps have steel leads, more epoxy and plastic on the ends and are put in with no thought to outside foil orientation.  All these things are important for sound.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: farquad on 2 Oct 2013, 05:41 am
The problem with hearing is its not 100% what the ears are registering. The brain uses any relevant information to interpret what you are "hearing".
If what the eyes tells you is in conflict with what the ears are registering, the brain might go with what the eyes tell the brain it should be hearing.
Have you heard of the MCGurkeffect?
http://www.youtube.com/watch?v=G-lN8vWm3m0

So if you "want" your modification to sound better, there is a big chance it does sound better. To your brain. But that doesnt mean there is a difference to the sound.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 2 Oct 2013, 12:10 pm
It could also be that it sounds "better" to you. That doesn't mean that the amp has been objectively improved, it means it sounds different.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 2 Oct 2013, 12:11 pm
It could also be that it sounds "better" to you. That doesn't mean that the amp has been objectively improved, it means it sounds different.
Bingo!!!!





Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 2 Oct 2013, 12:49 pm
It could also be that it sounds "better" to you. That doesn't mean that the amp has been objectively improved, it means it sounds different.

If it sounds better to John, it is better to John. It makes him enjoy his system more.

I, on the other hand, don't see enough evidence that it would improve things for *me*. That is of course for each one of us to decide. We have no objective evidence either way.


Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jackman on 2 Oct 2013, 01:16 pm
This has officially turned into a standard cap argument.  Give the guy a break, he's doing the exact thing I've seen so many people do. He changed caps and it sounds better to him.  Cap threads always devolve into arguments. 

Also, every person who mods a piece if gear thinks it sounds better.  How is this different?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jackman on 2 Oct 2013, 01:17 pm
Sorry, duplicate post.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: rklein on 2 Oct 2013, 01:33 pm
Quote
This has officially turned into a standard cap argument.  Give the guy a break, he's doing the exact thing I've seen so many people do. He changed caps and it sounds better to him.  Cap threads always devolve into arguments. 

+1

Y'know what else is not being said in this way too long thread and what is so cool about the ability to DIY...

If John didn't like the results of his mod...guess what....he can always put the original type cap back in!!  :lol:

Regards,

Randy

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 2 Oct 2013, 04:47 pm
I think we should have a single "objectivist type" person always interject a single number "7" instead of the usual:

1. Not valid because you did not measure it.  It must measure better for it to mean anything.
2. Not valid because you did not do a blind ABX test.
3. Not valid because you just listened to it and we are subject to our own delusions and sounding different is not necessarily better.
4. Not valid because you did not contact the designer and ask his opinion of this mod/listening test.
5. Not valid because it is not valid science....hence is voodoo.
6. Not valid because I did not think of it or invent it. 
7. etc. etc. etc.

So, which of you objectivists wants to be the #7 injector?  So, on any thread after any post there will be just one same guy who posts nothing but a #7.  This way we know the "scientific objectivists" are watching over our every move and are enjoying their superiority....he he.  And this way we save bandwidth and don't have to read the same old things over and over.  There was a guy on Audioasylum who hated DVD-A.  He always interjected some trash....finally we just named his posts #9 if I remember correctly.  This way we had a lot of fun with him.  He eventually went away.  However, the objectivists are a religious group.  They feel they must state the "truth" because letting the majority of audiofools have their way would be against reality.  You have to realize that at least 80% of serious audiophiles are subjectivists.  The other group however is more adamant and are always on the forums letting everyone know that the "emperor has no clothes".  The major reason why there are not more subjectivists posting on line is the thrashing they get from the resident objectivists and they would just rather enjoy their music instead.

#7 could also be used by us subjectivists to let the objectivists know we know their sad story.  So, after someone posts about the sound of caps or whatever they can just put a #7 at the bottom of the post and the objectivist objections would already be covered.  This way the objectivists would never have anything to say.....he he.

I hope you enjoy my humor....I do. 
Love is all there is.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 2 Oct 2013, 06:13 pm
I think we should have a single "objectivist type" person

Why is it always the anti-objectivist types who want to paint the world as a black-and-white objectivist/subjectivist one?

Quote
You have to realize that at least 80% of serious audiophiles are subjectivists.

You have to realize that is just a silly generalisation with no basis in fact.  :)

Quote
I hope you enjoy my humor....

Likewise.

Quote
Love is all there is.

But my love is better than your love.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: drmike on 2 Oct 2013, 06:35 pm
go rick!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 2 Oct 2013, 06:49 pm
You have to realize that at least 80% of serious audiophiles are subjectivists.

Actually, you are probably right. I think that 80% corresponds to the number of people who mostly post stuff like "changing from my $3000 USB cable to an even thicker and shinier one with a bamboo box on it and a $5000 price tag made such a night and day difference to the sound of my system" while the 20% that actually understand the technology seem to be the ones posting actual useful information.

Music is art. Sound reproduction is engineering (applied science).

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 2 Oct 2013, 07:25 pm
+1 Julf!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 2 Oct 2013, 08:38 pm
Julf and Waver......you could have just used #7 in your replies (much better than +1!).  See how much simpler it is.  No, you have to have the last word......so sad.  Go on....you know you HAVE to reply again....he he.  If you really want to make it even bigger you could do #7+#7  or #7squared or #7 times infinity or just use a thousand explanation marks.

By the way, all parts and execution have a sound that cannot be measured and must be listened to....to determine the most pure sound.  There is not a single part that passes a straight wire bypass test....including wire.  Even every solder brand sounds different and some silver solders sound dull....really dull...try the Acer Racing solder...super high silver content and super dull sound.

#7
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: randytsuch on 2 Oct 2013, 11:15 pm
Imagine someone building an audio system, and only caring about how it sounds?  8)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 3 Oct 2013, 05:57 am
By the way, all parts and execution have a sound that cannot be measured and must be listened to....to determine the most pure sound.  There is not a single part that passes a straight wire bypass test....including wire.  Even every solder brand sounds different and some silver solders sound dull....really dull...try the Acer Racing solder...super high silver content and super dull sound.

I suggest we also number the standard "subjectivist" claims in order to save space.

But more importantly, you seem to think "objectivists" are people who don't care about how things sound, and only care about measurements - and that misses the point totally.

We all enjoy a good-sounding system, and don't need measurements to tell us what sounds good to us.

The important difference between so-called "objectivists" and "subjectivists" is exactly that last part- "what sounds good to *us*". We realize that our preference is just that - a subjective preference, and we also realize that the human ear-brain system is a rather easily deceived, imprecise and fallible gauge of absolute differences. Thus we know that while listening results are always the ultimate judgment of the sound quality of a system or component, controls and safeguards must be in place to ensure the preference isn't caused by factors other than the actual sound waves.

Ironically, "objectivists" believe in the subjectivity of the hearing experience, while "subjectivists" believe their own, personal and subjective preferences are the absolute truth. I suggest we rename "subjectivists" to "absolutists". Or maybe "solipsists".
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 3 Oct 2013, 06:41 am
I started this thread because of genuine interest in the fact that the caps and the speaker post used in the NC400 are generally known not to be the best sounding.

I have been to a number of liver shows and have the recordings, I also have a fairly good front end and testing software which delivers bit perfect data to the DAC, this software has significant gains over DLNA connected DAC's and the sound produced by the DAC is the best I have heard yet. once3 PS Audio makes this general release the PS Audio DAC will be elevated even further as an honest good sounding DAC. So I feel I have a front end reasonable original to the sound made by instruments and voice worthy of amplification when I compare recordings and the live show I'm very happy the Mod of the CAPS and speaker post in the NC400 bought me closer to the live sound I have heard that is my message.

I have benefited by others with there posts that got me thinking and into action which has allowed me to get closer to the live sound, that's what I care about and nothing else. If someone else reads these post and has the expertise, tools and interested in performing the mod because the time is right for them. They have been following audio for years and have read similar experiences by others. I write my experience to those. I'm happy to write the NC400 is blocking the highs and midrange which is there in the unit and a more defined bass can be heard by swapping out the caps and hardwiring the speaker post. It takes a fair bit of effort and skill to do the job that is for certain so its is not for all but then if keen you can take it to someone who can do the job ask them about swapping back the caps if you think the SQ has not been improved give your self some comfort there so all wont be lost. I found the NC400 very tolerant to the mod.

now hiding the power loom cable as I have I have not heard any benefit doing that.

I don't have any itch to think I need to mod my PS Audio DAC that says something doesn't it, I'm not driven to mod everything I own but the things which don't sit that well with me I will. The steel clamping post and the steel polyester leads it was good to rid those - are an audible compromise to sound heard by the EAR :thumb:   
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 3 Oct 2013, 08:23 am
"We realize that our preference is just that - a subjective preference, and we also realize that the human ear-brain system is a rather easily deceived, imprecise and fallible gauge of absolute differences. Thus we know that while listening results are always the ultimate judgment of the sound quality of a system or component, controls and safeguards must be in place to ensure the preference isn't caused by factors other than the actual sound waves."

Who is this we that you talk about?  This we realize, this we know?  You can only talk for yourself.  I trust my own experience completely.  I can tell when a component is more linear/more real sounding.  The ear-heart-brain system is the ultimate judge.  The ear-heart-brain is the most sensitive instrument there is.  Way more sensitive than any measurement machine.  When you learn to trust your senses....when you have done serious A/Bs over and over you realize that you can tell what is real and what is not.  The only thing that is real in audio is what you hear.  Your experience is real.  The measurements on a machine are not......they are just an indication of something that may have some validity or not.  Your direct experience is the only thing that is real.  We need no safeguards from our experience.  What we need is an open mind and an open heart.  Then you will let yourself experience all that is possible.  And what is possible is way beyond what we can even imagine.  We are infinite.  We are magic itself.  We are life itself.

I talk in duality to make a point.  We are all both objective and subjective.  It is a matter of amounts.  Balance is the point.  Extremism is always out of balance.  But direct experience is the teacher.  I measure things.  I respect what measurements can show.  I listen to things.  I respect what listening can show.  But I seriously respect other peoples experience.  If someone says they hear something I would never come in and try to squash their reality.....I would not try to find out if they listened with all the "safeguards" in place.  I trust peoples experience.  If I were in the same room listening to the same system then I would more than likely hear the same thing.  I have done lots of listening tests where we straight wire bypass tested solder, wire, caps and resistors....everyone in the room always heard the same thing.  I started doing A/B testing in the late 70s.  We would borrow 10 Supex cartridges from Sumiko and mount them on universal headshells and number them and listen to them all day.  There were always a couple that were the best...and one that was the absolute best.  Some were not good at all.  All these cartridges came with printed frequency graphs that seemed to have no correlation to the sound of the cartridge.  Once you have done this kind of test over and over (especially with others that hear the same thing you do) you start to really trust your own experience.

Here is a story I have shared here before:  An audiophile believed that amps, preamps and speakers sound different but he was adamant that wires were all the same.  He befriended a new person and started to turn him on to audio.  The two of them were invited over to my friends house where they were going to listen to some heavily modded Soundlab electrostats driven by a 3 megahertz bandwidth amp (seriously transparent sound).  There was another person there too.....he is the one that told me about this experience.  At one point they decided to A/B a couple of interconnects and the non-believer had to go into the kitchen so he would not even be in the same room.  The other 3 all listened and agreed on the differences between the cables.....including the newby that the non-believer had tried to indoctrinate.  He did not even want to be in the room where they were A/Bing.  If he stayed in the room then if someone asked him if he heard the sound difference.....what would he say?  Would he let himself be wrong after all those years of disbelief?  Could he even listen openly? 

Every single moment is a new blessed moment.  It is filled with infinite love, joy and beauty.  Can we allow ourselves to feel and experience it?  This is what we all have come here to do.  We have all come to awaken.  "Toward the one. The perfection of love, harmony and beauty, the Only Being"

Geez its not even Sunday and I'm preaching already...he he.

Now back to our regular program.

#7 times infinity   

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 3 Oct 2013, 08:43 am
I trust my own experience completely.

I know.

Quote
Geez its not even Sunday and I'm preaching already...he he.

Indeed.

Religion has it's place. But sound reproduction systems are not designed by religious visionaries. They are designed by engineers, applying science.

To make this at least somewhat relevant to this thread, let's take the example of the output cap mod of the hypex amp.

To keep this short, I will use the tag <DEASPK> to signify the phrase "designed by engineers applying scientific principles and knowledge".

The music you listen to was captured by microphones <DEASPK> and/or created by electronic instruments <DEASPK>. It was then amplified and processed by a recording chain <DEASPK>. The result was probably stored and processed, passing thousands of transistors, in a DAW <DEASPK>. The end result was burned on a metalized plastic disc <DEASPK> using a recording system <DEASPK>, or transferred as a digital file through numerous routers and switches on the Internet <DEASPK> and downloaded to your computer <DEASPK>. It is then processed, amplified and turned into sound waves in your listening system <DEASPK>.

Yes, it is possible that in that whole long chain, the weak component is the use of inferior caps at the output of your amp, and that they make a significant contribution to the resulting sound. But before I take that as a given and generalize it to the systems of other people, I might want to spend some time verifying it. But that's just me.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 3 Oct 2013, 08:51 am
I have not read the last two post yet and will do with interest.

One thing I'm not sure if it is being understood I'm not just talking about improved SQ but sounds that you don't hear with the stock caps and standard speaker post.

The modified NC400 with Mod WIMA caps by Ric Schultz and hard wired speaker posts I can hear instruments and sounds not heard with the unmodified NC400

Thanks
John
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 3 Oct 2013, 12:40 pm
I trust my own experience completely.

It's just that I don't trust your experience, or others, completely. It is subjective.

Different doesn't mean better for everyone.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 3 Oct 2013, 02:38 pm
How about the fact that I can hear sounds not heard with the stock unit and can't hear them with the modified unit not just that the SQ is improved. How about a focus on that particular point, I like that aspect a lot and is a big winner for me  :thumb:

These three facts made me mod my second pair after listening and comparing the units - there is more music heard and the SQ is improved also of great delight was the fact that the sound stage is more defined, at low volumes is like you have a pair of headphones on, the imaging just beautiful 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 3 Oct 2013, 02:44 pm
How about the fact that I can hear sounds not heard with the stock unit and can't hear them with the modified unit not just that the SQ is improved. How about a focus on that particular point, I like that aspect a lot and is a big winner for me

We are of course happy to hear that it worked for you! Excellent!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 3 Oct 2013, 06:55 pm

Yes it did get benefits exactly as I have described in my previous posts, what has been the point of all the previous questioning and placing doubt to my word is if not to trust my experience.


In the very first reply to my post when I ask for people with experience in having worked with these mods, the reply was none of advice but try it for your self that I did and am totally confident to advise as I have.

A one sure way to be certain then is anyone having such a strong opinion then try the mod yourself go to the small expense and trouble and report back the effect after listening a week - reverse it if not happy with the result :thumb:
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 3 Oct 2013, 08:39 pm
Yes it did get benefits exactly as I have described in my previous posts, what has been the point of all the previous questioning and placing doubt to my word is if not to trust my experience.

We trust your experience, but we aren't sure it can be generalized to anyone else.

Quote
A one sure way to be certain then is anyone having such a strong opinion then try the mod yourself go to the small expense and trouble and report back the effect after listening a week - reverse it if not happy with the result

I don't have a strong opinion, but I don't feel it is likely enough to cause any improvement in my system to go through the trouble. Others might, and hopefully report back - some might even do some blind tests.
Title: WIMA capacitor modification - polyester to polypropylene
Post by: cheap-Jack on 4 Oct 2013, 03:18 am
Hi.

So to sum up we don't have instruments available to day which can measure the difference we can hear with our ear yet we cannot make measurements to explain the difference in what we hear with our ear. There is lacking in a tool and a measurement, please find this tool and measurement to explain what we hear with our ear.
 John


As an audiophile/DIYer & an EE, I fully agree that the the objective measurement done with the instrumentatioin available todate can't tell what we HEAR.
So until that day in the remote future when such instrumantion is available to provide data relevant to what we hear, let us
let our ear to have the final say.

Back to the issue of replacing the stock PE caps with PP caps to get better sound that most most audio fans fond of doing. I've got the opposite sonic conclusion with the O/P coupling caps for my one-stage RIAA tube phonostage.

The WIMA metallized film caps I installed to replace the exsiting no-name PE film caps sounded much much worse that the PE film caps! Givng them the benifits of the doubt - the WIMA new PP caps need breaking-in to give good sound, I carried out a crash breaking-in process with a 20Hz-20KHz sweeping signals into the new WIMA PP caps already installed in my amp for 8 hours non-stop
at pretty high voltage (higher than its normal audio voltage range) to achieve the intended quick breaking-in result.

Such crash breaking-in process did improve a bit the sound of the new WIMA PP caps, but they still sound relatively dull, veiled, & lack of transparancy & details than the old PE film caps. The sonic difference was so huge that I can conclude such PE to PP caps swap is a complete failure (w/o need of any DBTs at all).

I had no choice but to swap back to the old no-name PE caps & threw out the new WIMA PP caps. The sound comes right back to fast, clean, transparent & musically like before.

Well, listening is believing.

c-J
   
Title: Any other polyproplene or polyester cap that would fit ?
Post by: EuroDriver on 4 Oct 2013, 05:30 am
I have known about Ric for about 15 years back in my Maggie modding days and I have great respect for his knowledge and experience.

I have had my dual mono NC400 running for close to a year now.  The mids and highs sound so good I can't imagine them sounding any better ( the system is playing in a heavily treated room)

For me, the report that one Wima poly had steel leads is pretty alarming.  Over the years I have become convinced that each material has its own sound signature, with rhodium, silver and copper at the top of my list.

About 18 months ago, I had a conversation with Andreas Koch of Playback Design about why conductor materials sound different.  He said it was all about the electrical resonant frequencies of the materials.  That's why the different materials have their sonic signature and why annealing, cryo treating and crystal structure all make a sonic difference.  The different sonic signature of dielectrics fits this elelectrical resonance theory well.

I am not fired up to try the mod, but I am always loth to leave SQ improvement on the table !

Are there any other polyproplene or polystyrene caps with the right package format and value that can be used ?
Title: Re: Any other polyproplene or polyester cap that would fit ?
Post by: Julf on 4 Oct 2013, 07:22 am
About 18 months ago, I had a conversation with Andreas Koch of Playback Design about why conductor materials sound different.  He said it was all about the electrical resonant frequencies of the materials.  That's why the different materials have their sonic signature and why annealing, cryo treating and crystal structure all make a sonic difference.  The different sonic signature of dielectrics fits this elelectrical resonance theory well.

Just to clarify, was he talking about the electrical resonance (as determined by the inductance and capacitance of a conductor - more dependent on the geometry of the conductor than the material) or perhaps some form of nuclear resonance?
Title: Re: Any other polyproplene or polyester cap that would fit ?
Post by: EuroDriver on 4 Oct 2013, 01:37 pm
Just to clarify, was he talking about the electrical resonance (as determined by the inductance and capacitance of a conductor - more dependent on the geometry of the conductor than the material) or perhaps some form of nuclear resonance?

Good question !  I would imagine the electrical resonance determined by inductance capacitance and impedance changes at junctions and boundaries for sure, but also nuclear resonance or perhaps molecular dipole resonance would have an effect too.  I am reminded about some development work done by NAIM many years ago with lead acid battery power for preamps.  The sound was very muffled and the work stopped.
Title: Re: Any other polyproplene or polyester cap that would fit ?
Post by: Julf on 4 Oct 2013, 01:49 pm
I would imagine the electrical resonance determined by inductance capacitance and impedance changes at junctions and boundaries for sure

The Q value of any of those resonances would be extremely low (except at very high frequencies - way above audio), and as I stated, they are mainly determined by geometry and layout (and isolator material), and not by core material choice.

Quote
but also nuclear resonance or perhaps molecular dipole resonance would have an effect too.

Hmm, "maybe any possible resonance might have some effect" doesn't sound like much of an explanation to me.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 4 Oct 2013, 04:11 pm
while I try to eliminate steel and other magnetic materials from the signal path as well, I must point out that the Ncore modules have a lot of steel parts in and close to the signal path.  Note the screws which terminate the speaker leads are steel (in my amp, they, and the terminals are removed and the wiring to the binding posts are soldered directly into the board).  But, what is probably even more of a potential problem, is that all of the SMD resistors on the board likely have steel endcaps, and all the electrolytic caps are almost certainly have steel leads as well.
Just something to think about...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 4 Oct 2013, 07:53 pm
After reading all these post about the comparison I made between the stock NC400 amp and the NC400 with swapped out capacitors and speaker posts. I suggest other opinions have little ground as they are comments and just that, they don't have any solid proof behind them as the commenters have not heard the results with there ears themselves.

Comments are pure speculation and are same thoughts I had before I commenced and proved to myself following taking the required steps to prove the changes to myself using my hearing as the test tool. The change has not impacted the musical rhythm, is unaffected too the toes continue to tap

Thanks
John
 


 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 4 Oct 2013, 08:00 pm
I suggest other opinions have little ground as they are comments and just that, they don't have any solid proof behind them as the commenters have not heard the results with there ears themselves.

True. They are just based on common engineering knowledge, not the much superior subjective opinion of one person.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 4 Oct 2013, 11:35 pm
Opinions not based in reality (direct experience is the only reality) are pure conjecture....and are therefor lies.  The truth about how something sounds is how is sounds.  Not what you THINK it should be.  So, a listening test is always superior to conjecture.  You, my friend have no direct knowledge on the subject....you are essentially ignorant.  Nothing wrong with not knowing.  When it is disguised as "superior common engineering knowledge" then it is just the ego pretending to be superior.  You have no clothes on.  You have no knowledge.  You only have book learning.  You have not experienced this with your own ears.  The most pure and sensitive instrument there is.....is our ears (relating to sound reproduction).  If you do not use them then you are just in your head and pretending to actually know something.  Your comments are useless.  It's as if someone lived in a cave and never saw the sky but had a book on what the colors are but was told by his cave teacher that the sky outside was green.  So, one day this person finally goes outside the cave and looks at the sky and thinks to themselves....hey, it does not look green to me....looks like it is blue.  So, was his cave teacher correct or is his experience correct?  So, are you the cave teacher/student stuck in your cave or are you ever going to go outside and look (listen) for yourself to see (hear) what is REALLY TRUE?!!!!?

This openness to experiencing what is.....is what makes us more than animals....even more than human.  We have curiosity.  We have imagination.  We have will.  We can experience all life.  We can know the truth....about anything....including our own basic nature.  Would you like to know the truth....or just be right?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 5 Oct 2013, 08:02 am
All I can say is that I am very glad Bruno Putzeys relied on his book learning, theoretical understanding and engineering skills when designing the nc400, instead of sitting in a coffee shop trying to experience all life.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 5 Oct 2013, 10:09 am
Opinions not based in reality (direct experience is the only reality) are pure conjecture....and are therefor lies.  The truth about how something sounds is how is sounds.  Not what you THINK it should be.  So, a listening test is always superior to conjecture.  You, my friend have no direct knowledge on the subject....you are essentially ignorant.  Nothing wrong with not knowing.  When it is disguised as "superior common engineering knowledge" then it is just the ego pretending to be superior.  You have no clothes on.  You have no knowledge.  You only have book learning.  You have not experienced this with your own ears.  The most pure and sensitive instrument there is.....is our ears (relating to sound reproduction).  If you do not use them then you are just in your head and pretending to actually know something.  Your comments are useless.  It's as if someone lived in a cave and never saw the sky but had a book on what the colors are but was told by his cave teacher that the sky outside was green.  So, one day this person finally goes outside the cave and looks at the sky and thinks to themselves....hey, it does not look green to me....looks like it is blue.  So, was his cave teacher correct or is his experience correct?  So, are you the cave teacher/student stuck in your cave or are you ever going to go outside and look (listen) for yourself to see (hear) what is REALLY TRUE?!!!!?

This openness to experiencing what is.....is what makes us more than animals....even more than human.  We have curiosity.  We have imagination.  We have will.  We can experience all life.  We can know the truth....about anything....including our own basic nature.  Would you like to know the truth....or just be right?

I realize you posted that at 11:35 pm on a Friday evening. I remember Google having an experimental feature, "Mail Goggles", that required you to successfully solve some simple math problems before letting you post late at night on weekends. Maybe forums should have a similar device?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 5 Oct 2013, 11:37 am
All I can say is that I am very glad Bruno Putzeys relied on his book learning, theoretical understanding and engineering skills when designing the nc400, instead of sitting in a coffee shop trying to experience all life.
+1
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 5 Oct 2013, 01:10 pm
+2....

Funny how these ignorant engineers design these things then along come the zen tweaker gurus, always on the coat tails, who despite never designing a complete piece of equipment in their lives, somehow know better than the designers with claims they have "improved" them. "Stupid" Bruno was smart enough to design the amp but not smart enough to know how a simple piece of wire or a capacitor can take the amp into the twilight zone.....

Like the guy who paints racing stripes on his car and claims it goes faster because it looks faster....

If you have such a command of what it takes to design a top flight class d amp, why don't you design and build your own instead of hacking the work of Hypex, Icepower, etc.? My guess is because you lack the fundamental engineering skills to do so and it is much easier way to make a buck by simply changing a wire or capacitor and claim you have "transformed" the amp...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: fsimms on 5 Oct 2013, 01:15 pm
You are like the guy who paints racing stripes on his car and claims it goes faster because it looks faster....

Everybody knows that the only way to make a car run smoother and faster is to wash an wax it.  :nono:

Bob
Title: TIME OUT ! Let's be civil !
Post by: EuroDriver on 5 Oct 2013, 03:36 pm
Personal attacks have no place in a forum where the members are sharing their knowledge and experience in a common pursuit of good sound !

Although my experience is that a heavy majority of posters are actually misinformed, I still appreciate every one who takes time to post ! 

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 5 Oct 2013, 04:37 pm
Or you can switch to a Job 225 amp and never buy another Class D amp. No Class D amp made today has the transparency of a Job.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 5 Oct 2013, 05:08 pm
Or not, and wait till next month for the new flavor...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Jon L on 5 Oct 2013, 05:20 pm
Or you can switch to a Job 225 amp and never buy another Class D amp. No Class D amp made today has the transparency of a Job.

JOB's reasonable pricing introduces some interesting issues in my estimation. 8)  Since it really does not add any extra richness, bloom, or forgiveness, users who match it with similarly-priced front-end and speakers, not to mention cabling, may find the sound a bit "naked" so to speak..
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 5 Oct 2013, 05:55 pm
Or you can switch to a Job 225 amp and never buy another Class D amp. No Class D amp made today has the transparency of a Job.

What hypex modules does the Job 225 use?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: *Scotty* on 5 Oct 2013, 06:32 pm
References to the Job 225 are off topic. See review at 6Moons  http://www.6moons.com/audioreviews/job/1.html
also http://www.jobsys.com/
Scotty
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 5 Oct 2013, 06:33 pm
Since this is the Hypex circle, you would expect that it did indeed use Hypex modules. Truth be told, it isn't class d. Just an off topic, gratuitous plug....
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 5 Oct 2013, 07:08 pm
Truth be told, it isn't class d. Just an off topic, gratuitous plug....

Kind of what I was noticing. But I am sure we can squeeze a few more off topic, gratuitous plug links in...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 5 Oct 2013, 07:21 pm
References to the Job 225 are off topic. See review at 6Moons  http://www.6moons.com/audioreviews/job/1.html
also http://www.jobsys.com/
Scotty

 :duh: Oops, forgot.

I still see anybody modding their NC 400's is off-topic here also. I feel sorry for revelinhifi whom is getting bashed for just modding his to make them sound better.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 5 Oct 2013, 07:45 pm
OK.


Time to get back to the thread of modding the NC400.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 5 Oct 2013, 07:55 pm
I still see anybody modding their NC 400's is off-topic here also.

If you say so.

Quote
I feel sorry for revelinhifi whom is getting bashed for just modding his to make them sound better.

Bashed? I think all we said was "good if it works for you, but there is no evidence it would work for anyone else". Is that a factually false statement?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 18 Oct 2013, 03:23 pm
I just had a thought, is it possible to use fewer capacitors? Maybe even just on? The performance may improve slightly for audio signal (this wouldn't be advisable for power sections)

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 23 Oct 2013, 02:25 am
I tried listening to the amp with just two caps in parallel (1.36uf total)...sounded thin and wirey.....a no go.  Did measure a little wider bandwidth, but not much.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 24 Oct 2013, 03:32 pm
I wouldn't lower capacitance, but in the audio signal higher ESR might perform better and the obvious is one big cap, maybe a small bypass one but I dunno if it'd be needed.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 26 Oct 2013, 02:11 am
Know it all engineer types here who seem to imply that Bruno Putzeys relies only on "book learning" and measurements need to read his responses at DIY audio.  He designs both by measurements and confirms by listening.  If things do not sound right he goes back and does revisions.
Not only that, he is well aware that different capacitors do affect the sonic performance of his Ncore amplifier designs.  A specific example is the Mola Mola amplifiers.  Mola Mola's own website mentions specifically that the output filter capacitors for the amps were carefully chosen monolithic types for best performance.  (Note that these are different than the caps included on the OEM NC-1200 modules).
Often parts are chosen not for the best sound quality possible, but for other reasons: ease of manufacture, form factor, availability, cost, etc...  anyone who thinks a cost no object design process was applied to the NC-400 modules needs a wake up call...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 02:53 am
Certainly not a cost no object process, more a max performance process.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Rclark on 26 Oct 2013, 06:34 am
A wake up call? That's exactly what the nc400 was.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 26 Oct 2013, 03:36 pm
Rclark:  I'll bite, in what way?  Measured performance?  I have a NC-400 amplifier here, so I am experienced with it.

Cab: If the NC-400 parts were chosen for maximum performance, how would you explain why the Mola Mola amplifiers use a completely different type of capacitor in their output filters (and completely different from that used on the NC-1200 OEM modules)?  Are you suggesting that Mr. Putzeys has used a worse performing part in his flagship amplifier design?  As Mola Mola notes this capacitor choice in their marketing, it certainly appears to me that they feel the different capacitor offers better performance.

IMO, the use of a different type of cap on the flagship Mola Mola amps indicates that Bruno Putzeys is well aware that different caps do effect the performance of the amps, and that, additionally, the caps on the NC-400 are not the best possible ones to use.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 03:57 pm
Look at the specs and tell me how a cap change would make a meaningful (i.e. audible) improvement in the measured performance.

Different cap might make it sound different, maybe better to some, but that is a subjective change that might not be interpreted by all listeners as an "improvement".

If you want to know why they use something different in the Mola Mola, why don't you go to the source and ask them instead of speculating here? Speculation is rather pointless, but perhaps you hit the nail on the head when you used the word "marketing"...In that vein, perhaps those that spend $15K on an amp would find comfort in knowing they are getting something "special" that sets it apart when paying 10x as much....
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 04:13 pm
The industry is based on subjectivity. There are capacitors people greatly prefer that are expensive, but perform on paper just like cheap ones.

Thing is our ears are sensitive in the terabytes worth of information, every second. While our frequency and sound level sensitivity isn't that high, we can read the subtle differences in sonic qualities very well. We are sensitive to types of distortion we don't know we are hearing; we can hear the difference in capacitors.

Maybe I overlooked something, I'd only refer to input caps the signal goes through. If the output caps are parralel to the load then I doubt there is a big difference. But in that case the more smaller overall caps with low ESR/ESL the better. If signal passes the opposite will likely be best.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: undertow on 26 Oct 2013, 04:17 pm
Alright Kids... Lets get to the brass tacks.

I actually was one of the first to ever build and purchase this DIY KIT.

That's the point its a DIY KIT!

First off remember a few things. They buy 10,000 caps at a time, and guess what at that point 23 cents more PER cap adds maybe 5 dollars to an entire unit, but multiply it by hundreds of units and yes you end up with the cheapest possible

"SMD" mounted materials vs. trying to one up everything.

So do I believe in fact simply "Steel" Leads vs. "Copper" Leads can make a pretty significant difference in such a precise and accurate designed circuit... HELL YEAH!

No question. For example I have worked around Steve McCormack’s gear for years. Modified and not modified. Well guess what when he came back with his Revision series for DNA amps, and several other:

"TWEAKS"

These amps virtually sound nothing like the other. Everything improves period.

Why would these companies NOT do this in the first place then?

Well a set of standard Nichicon industrial production caps in an amp might cost you something like 1.50 each... No big deal right? The Equivalent "ELNA" or "Nichicon Muse, Gold Tune" caps only cost about 4.50 to 6.50 each...

Why not use the Gold caps? Well literally now if you do that to every part in the amp including better resistors, caps, wire adds up to 5 times the price in parts to build that amp!

So on an individual basis it’s much easier to sell the masses on 2000.00 worth of part upgrades years later when they realize they want it and the design is solid vs. trying to charge 7000.00 for an amp you guys right now are building instead for 2000.00.

You have to remember these companies make no more money on selling you on the better “Chinese” part. They only make money on the design from the beginning.  All the extras would just put these designs well out of reach for most and posters on this forum would never even consider these kits at those prices.

So be happy you can go out and simply spend a couple hundred on your own to upgrade, besides your handy already and built these items in the first place.

So I commend the attempts on both sides of the "Snake oil" believers, and those that think they can debunk the "Snake oil" with their "fundamental" measurements and you need to prove it to me stance.

Bottom line you can measure anything with a copper wire, and it’s a good conductor for most applications, but believe me if you go PURE SILVER in that same spot your measurement won’t  necessarily change it, but you will HEAR IT trust me.

I want to make very clear none of this reflects directly on this “Mod” in contention here for the NC400, just simply don’t believe the hype, but also don’t believe that you cannot make significant improvements using better materials in any circuit plain and simple.

By the way another thing that was fought over for months on the SM600 power supplies was they did not run hot enough to effect performance.

Well I had one fail, they replaced immediately with great customer service, however I went steps further not only improving the heat dissipation, but in fact making the unit perform and sound better as a whole.

I no longer own the NC400, but that has nothing to do with any of it.

There is nothing wrong with this amp... It does just as it should. Is it the most refined most powerful do it all amp on the planet?

Bottom line its efficient, compact, and a good design for you to put in your own case. It meets the requirements the market demands, but its not the last word and really even if it was marketed by some as being so that's for you to decide.

Lets just get one idea straight :

Sound is the key, tone, quality, musical capability with consistent results. Sometimes this takes more than a measurement showing a difference between materials, thats all I want to contribute to that.

Maybe this goal is met by a paper graph to many, maybe its met by pure enjoyment in listening to one unit over the other.

Regardless which is better than the other, bottom line things do sound different, if they did not you would not be in this crazy hobby still searching!
 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 04:29 pm
Bruno has gone on the record repeatedly as saying his goal when designing an amp is to make it as neutral as possible, that is, with no "sound" of its own. No doubt come parts may sound different, but "better" is in the mind of the listener. Claiming a mod or tweak has improved the amp is valid for you and your tastes but it means nothing in an absolute, objective sense and as such, doesn't necessarily mean that everyone would agree. If you like it, good for you.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 26 Oct 2013, 05:45 pm
Bruno has gone on the record repeatedly as saying his goal when designing an amp is to make it as neutral as possible, that is, with no "sound" of its own. No doubt come parts may sound different, but "better" is in the mind of the listener. Claiming a mod or tweak has improved the amp is valid for you and your tastes but it means nothing in an absolute, objective sense and as such, doesn't necessarily mean that everyone would agree. If you like it, good for you.

What?  Absolutely untrue.  First, let's accept the premise that neutral/transparent performance is the goal.
OK, now, if you change the output capacitors (they are in parallel, this is a low pass filter L/C), and the amplifier becomes more neutral/transparent, then that is an improvement in performance, not a "different flavor" sound.  First, understand how a capacitor degrades sonic performance: the dialectric absorbs some signal, and then releases it in a delayed fashion.  This time delayed release of the signal smears the sound, degrading it from absolute transparency.  The closer the capacitor comes to "perfect" performance, the less smearing of the input signal,  and the closer the amp is to absolute transparency.

It is a mistake to assume that changing an output filter capacitor cannot impove the perfromance in an absolute sense (improved transparency).
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: undertow on 26 Oct 2013, 05:55 pm
Agreed...

If it sounds better @ "neutral" with one part over the other its still "neutral"  and it just still sounds better. Whether it just has a better quality, balance, or "Transparency" about it whatever the case may be; it can be an improvement with more of the same thing.

Plus this is never about what you gain putting in a different part or wire -

It's more about what you have no idea your losing until sometimes putting in a better part!

You can never add better sound which is simply there if the parts, and wiring allow it in the design without causing further damage to the delicate signal.

This in general can only be recognized via true listening with experience on what a unit is doing in the first place and this is a PERFECT example of what the original poster is trying to illustrate in this case.

The conversation simply went beyond that.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 06:09 pm
The upgrade might have been from doubling the amount of capacitors. Lead changes alone are unlikely to make a particularly noticable improvement by them self for somethingusic signal does not pass through.

Using audio grade capaictors here would be a mistake unless you greatly increased the number of them to counter their higher ESR.

Trick is to use as many capaictors with low ESR as possible, that equal the same value as oroginal 3.

Doing this means a lower noise floor from speaker. That is not subjective. Music signal doesn't go through the caps. The discharge of caps grounds through the amplifier at any significance, and not your resistor know as a speaker.

I was wondering why you'd have 3 input caps!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: undertow on 26 Oct 2013, 06:17 pm
I agree with this as well, but remember the more tricky thing in a circuit like this or many is "Value" vs. "Size"... Caps for quality cost money, but they also come at a cost of realestate and values available many times. Obviously you have very little working room in this unit, look at just the example in this case, even in the photos going to the smaller .33 value went larger, but had to stack 2 on top of each other just to come close to the original value!

By the way traces in a silicone board would be much worse in Steel vs. Copper so why not just use steel then just like in other leads? Its a sum of all parts so using any inferior link could shift this whole thing in such an intricate circuit.

One cap with steel leads vs. copper may or may not make or break anything, and that was not my point to be honest normally higher grade components use better materials as a whole, not just one metal vs. the other.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 06:24 pm
Sure, to an engineer it'd seem silly, but to my ears I'd be fine with having little gardens of capacitors.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: undertow on 26 Oct 2013, 06:29 pm
That's correct... Because the bulk of engineers use these parts for industrial applications where the "sound" or related frequencies in the outside acoustic world have nothing to do with it!

Some of these parts are perfect, reliable, and do just what you need to handle the thermal requirments running a DC motor or something all day.

For Audio this gets way more tricky, and why so many details matter which may not be measurable within the "Industrial" standard sets of measurments. Sure you will get it to work just "fine", but is it that "refined".

If Hypex wants to provide a module like this larger than a Hockey puck I am sure they can get all the audio grade components on board these guys want.

But it will come at a cost.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 06:42 pm
I prefer to concintrate on key areas. Non-signal areas don't need $12 vishay resistors, but in the signal path it is worth it. But I do remember that Hypex said something about using surface mount because recently greatly improved parts on the market made it a practicle way to make a high end unit.

I understand the cost part. Small price changes in parts mean a lot. $5 can translate to $40 after labor, markup, shipping, and retail. Safe to say I think most making products do their best to not waste money on anything less than significant.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: undertow on 26 Oct 2013, 06:48 pm
Of course!

By the way I think the NC400 module is great for what it does. Not the point.

Development in all the SMD stuff had to happen. IPOD

Actually an ipod is not all that bad in sound. Advancements in micro sound circuits are far beyond what they were 10 years ago no question.

And hey Hypex is one on the forefront of putting them into more conventional stereo applications.

Now the question is would you use your Ipod with its Headphone out as a full on Preamp direct into an amplifier?

Probably will not compare to a Preamp loaded with gain, larger power supplies, and great hi end film caps all over the place, but hey it does exactly as advertised, and for most people thats a big step in the right direction.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 06:52 pm
What?  Absolutely untrue.  First, let's accept the premise that neutral/transparent performance is the goal.
OK, now, if you change the output capacitors (they are in parallel, this is a low pass filter L/C), and the amplifier becomes more neutral/transparent, then that is an improvement in performance, not a "different flavor" sound.  First, understand how a capacitor degrades sonic performance: the dialectric absorbs some signal, and then releases it in a delayed fashion.  This time delayed release of the signal smears the sound, degrading it from absolute transparency.  The closer the capacitor comes to "perfect" performance, the less smearing of the input signal,  and the closer the amp is to absolute transparency.

It is a mistake to assume that changing an output filter capacitor cannot impove the performance in an absolute sense (improved transparency).

How do you measure "more neutral/tranparent"?  How do you measure "smear"? I am not saying you can not improve absolute performance with component changes. I am saying what you think you hear and what is actually happening on an objective basis may not be the same thing. Just because it sounds better to YOU doesn't mean you have improved the measured performance.

First show us some measurements before and after the cap switch. Then prove any objective improvements are actually audible.

By the way, my comments attributed to Bruno are public record. You can search the net and easily find them.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 26 Oct 2013, 07:07 pm
First show us some measurements before and after the cap switch. Then prove any objective improvements are actually audible.
Bam!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: a.wayne on 26 Oct 2013, 07:08 pm
Tuff group ......:)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: undertow on 26 Oct 2013, 07:20 pm
Maybe I am in the wrong argument here. Not sure what measurement is necessary or quite honestly what people are actually doing arguing this fact?

I have actually in the past taken a Cartridge for turntables for those not very familiar with...

Now these cartridges were all measured...

Same output, lets say .4 mv, same impedance, same compliance, etc...

On anybodys spec. sheet says the EXACT SAME THING. All of these cartridges should just simply work exactly the same in every single system right?

Guess what? Some sounded WAY different than another with identical meausured specs.

This can be due to the type of WINDING inside, I guess you can argue that being similar to the capacitor design vs. application, and or other materials, due to the fact its a copper based , Silver based.. Whatever.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Occam on 26 Oct 2013, 07:26 pm
Sure, to an engineer it'd seem silly, but to my ears I'd be fine with having little gardens of capacitors.

Twaddle. EEs are quite aware that the constraints of an LC lowpass filter, preventing them from functioning ideally is the IWC (interwinding capacitance) of the inductor, and the ESL (equivalent series inductance) of the cap(s). And they obviously know that paralleling caps lowers net ESL, as they tend to be quite good at high school algebra. Paralleling caps has been used by engineers for decades in RF, digital and ps applications.
http://www.n4iqt.com/BillRiley/multi/esr-and-bypass-caps.pdf
http://www.ultracad.com/esr.htm
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: undertow on 26 Oct 2013, 07:29 pm
By the way all of this pretty much only applies to AUDIO related sources. Hell take a flat panel TV and put another capacitor all over the place vs. the old ones and you probably will care less! Same overall performance. The acoustic generation of sound is a very different world and why this forum exists.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 07:34 pm
Sorry cab, in this case it can all be measured by changing the capacitors. It isn't a subjective thing, as some of the language would make you believe.

Doubling the capacitors halfed the circuit ESR. Think of it in simple terms.

8 ohm resistor in parrallel with .5 ohm. Now the .5 ohm gets turned into .25 ohm, less curent will go through the 8 ohm speaker. However that is only true of current in the frequency range the LC circuit affects. ( it's more complicated but that's the concept)

Hence it will be whatever adjective you use for closer to input signal.

Smear can be measured in the same way, impedence of the speaker vs impedence of the ground.  Luckily speakers don't go negative impedence, but often increase, so the capacitors discharge towards circuit ground mostly. This can be measured, but realisticly the only way to improve it is create negative resistance to ground.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 07:40 pm
Sorry cab, in this case it can all be measured by changing the capacitors.

as I said, I have no doubt that there can be an improvement in objective performance (measurements). I said first, show the measurements, then prove the improvement is audible.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 07:42 pm
Twaddle. EEs are quite aware that the constraints of an LC lowpass filter, preventing them from functioning ideally is the IWC (interwinding capacitance) of the inductor, and the ESL (equivalent series inductance) of the cap(s). And they obviously know that paralleling caps lowers net ESL, as they tend to be quite good at high school algebra. Paralleling caps has been used by engineers for decades in RF, digital and ps applications.
http://www.n4iqt.com/BillRiley/multi/esr-and-bypass-caps.pdf
http://www.ultracad.com/esr.htm

What's your point? I said they don't care, not that they don't know. Obviously at Hypex they decided 3 was the best compromise. 

Now do our ears say the same thing? Well given that the type of noise they filter, any reduction, even in what we typcially think of as neglegent amounts in theory, might be an improvement. Which is what everyone is saying to be true that listens to the mod.

Cab, what about trying to prove it is not audible?  :green:

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: undertow on 26 Oct 2013, 07:45 pm
Cab,

I think the issue here is somebody going to the time, and expense doing this to prove something that may or may not matter for a 10 dollar upgrade.

I would guess the only way to get a true call on this would be to have Hypex actually do the test and post their results.

So trying to squeeze juice from a stone on this forum does not look like it will get the results necessary to end the debate.

The original poster obviously never had the intent to get "Professional" results measured from this change, but simply was giving some DIY guys the heads up he thought it was a nice improvement as part of the audio community. I don't think anybody here is making money off trying to get someone to waste a few bucks and a couple hours of time to do a small mod.

I could understand the resistance to it more if this was someone trying to sell you a 1000 dollar upgrade to modules that cost about that much, but in this case they are not.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 07:47 pm


Now do our ears say the same thing? Well given that the type of noise they filter, any reduction, even in what we typcially think of as neglegent amounts in theory, might be an improvement. Which is what everyone is saying to be true that listens to the mod.

Cab, what about trying to prove it is not audible?  :green:

Might be. Might not be. What is the level? Ncore's distortion is already below the noise floor and well below what is considered the threshold of human hearing. Thus I have my doubts that improvements in distortion performance will be audible.

Everybody? How many is everybody? DBT testing? Lots of things can influence one's perceptions. If the tests weren't scientifically conducted, I question the validity of the results.

You can't prove a negative.....
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 07:53 pm
Cab,

I think the issue here is somebody going to the time and expense doing this to prove something that may or may not matter for a 10 dollar upgrade.

I would guess the only way to get a true call on this would be to have Hypex actually do the test and post their results.

So trying to squeeze juice from a stone on this forum does not look like it will get the results necessary to end the debate.

The original poster obviously never had the intent to get "Professional" results measured from this change, but simply was giving some DIY guys the heads up he thought it was a nice improvement.

I could understand the resistance to it more if this was someone trying to sell you a 1000 dollar upgrade to modules cost about that much, but in this case they are not.

I agree that Hypex would be the logical choice and that they are in the best position to do so.

I am not saying that the OP didn't get an improvement in HIS listening experience. What I take issue is calling this an improvement in the performance of the ncore and claims that this is an objective improvement based solely on subjective listening. If the OP wants to say,"hey, check this out, it sounds better to me", fine. But saying more is an unfounded stretch. Again, like I said, if it sounds good to you, great.....
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 26 Oct 2013, 07:54 pm
Alright guys, whoever wants to have their modded amp measured on a dScope (http://www.prismsound.com/test_measure/products_subs/dscope/dscope_home.php) let me know and I'll make it happen.  Then we can compare back to the published measurements.  I do find it comical how nobody will ever step up though but yet talk all about measurements.   :duh:   
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: undertow on 26 Oct 2013, 07:57 pm
Again seems to me that logically this is a pretty cheap upgrade, yet not that critical to go this deep.

I have seen debates on several other types of upgrades that cost hundreds or thousands, at least this unit is virtually nothing to do the change and find the results.

I really doubt the unit would be "Worse" which is funny with some upgrades as they could go that direction!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 08:16 pm
Cab, have you watched the videos drom ESS talking about how the type of distortion mattered more than how low it was below the noise floor, for whatever reason, to the human ear?

I have only found support for this based on everything I read and test. I have no reason to believe otherwise.

There for I conclude that the typical noise from a not tube no matter how small, should be reduced or changed as much as possible.


And trust me, I'd love to know why since it doesn't make sense given what we know about audible sound levels.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 08:58 pm
Are you saying the ncore is a digital device?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 09:14 pm
It's a switching device. I think digital vs analog, but its actually tube vs not. Switchers require an oupit filter because the device operates with high frequencies above the music spectrum. It's not a pleasant distortion to the music like tubes.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 09:29 pm
First you were talking about ESS and digital arifacts/distortion types. Then you edited it to say tubes vs. analog....

Your original argument was that there were distortions identified by ESS in digital that were audible despite not being measurable. So I asked if you thought the ncore was a digital device. It's not.

Now you are talking about ss versus tube distortion spectra. Tubes are often said to soft clip-producing even, rather than odd harmonics that most solid state amps produce...This is only relevant in clipping situations. I am not talking about clipping situations.

The output filter removes the carrier residual.  I think you need to do a little more research into class d.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 26 Oct 2013, 09:48 pm


First show us some measurements before and after the cap switch. Then prove any objective improvements are actually audible.

So do you say that all amps will same exactly alike if only they would get their distortion specs exactly the same as Bruno's?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 09:50 pm
The ESS example was for after conversion to analog. The point is still the same, the type of noise matters, even at levels below what we consider audible.

The phenminon isn't constrained to digital specifically. Also tubes are very different even not clipping. All devices create some distortion/noise. The Wikipedia article on tubes is pretty extensive these days, have a look.

The LC circuit doesn't remove 100% of what the switching device adds to the music. That's why "everybody" (the people that have tried the mod) believes to hear something, a reduction in something that the noise caused or was. If the noise was from tubes they may not care; but the point remains it's the type, not the level, that can exlain "inaudible" differences in taste.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 09:55 pm
So you are saying that while the measured distortion from the ncore is below the noise floor of the measuring equipment and the threshold of human hearing, there is some type of residual distortion, not measured, made by the caps, that is audible? And that by changing caps, this heretofore unmeasured distortion is now reduced to a level where it is no longer audible? Pardon my skepticism.....what might this distortion be called and can you explain why we can't measure it or why it doesn't show up in any of the measurements done by Hypex?

I have seen nothing that proves noise spectra below the threshold of hearing is audible in general, and class d spectra, in particular. Isn't that what "threshold of hearing" means?

Instead of arguing the point with me, as I really don't matter, why don't you ask Bruno his opinion. He is usually very open and willing to discuss his work and these types of topics. While you are at it, you can ask him what he thinks of these cap mods.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 26 Oct 2013, 09:56 pm
Instead of arguing the point with me, as I really don't matter, why don't you ask Bruno his opinion. He is usually very open and willing to discuss his work and these types of topics. While you are at it, you can ask him what he thinks of these cap mods.
Great idea and please report back here with the answer. 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Regnad on 26 Oct 2013, 10:05 pm
I do find it a bit strange that mods almost aways improve the sound and equipment only burns-in until it is perfect, not more.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 10:07 pm
No I'm not saying any thing about capacitors creating noise/distortion. That doesn't make sense.

The capacitors are part of a filter. I am saying due to how-no-one-knows-low-noise-effects any improvement in the filter is positive to our ears. If what was being filtered was a different type, we perhaps wouldn't notice the change.

I'd love to hear from Bruno so long as he tries the mod.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 26 Oct 2013, 10:10 pm
[size=78%]I'd love to hear from Bruno so long as he tries the mod.[/size]
Maybe he has.  Ask. 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 10:12 pm
No I'm not saying any thing about capacitors creating noise/distortion. That doesn't make sense.

The capacitors are part of a filter. I am saying due to how-no-one-knows-low-noise-effects any improvement in the filter is positive to our ears. If what was being filtered was a different type, we perhaps wouldn't notice the change.

I'd love to hear from Bruno so long as he tries the mod.

It makes no sense that a filter already outputting a signal with measured distortion below human hearing now outputting distortion even farther below human hearing can make an audible difference. Below audibility is below audibility.

My advice was for you to contact Bruno and posit this theory and mod to him. See what he thinks. You can reach him via hypex.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 26 Oct 2013, 10:29 pm
Or if the mod sounds better to your ears, who cares what anyone else thinks?

So are we back ro the 70's again where low distortion only matters? I remember being young and naive back then and falling for this hype.

Never again.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 10:30 pm
Or if the mod sounds better to your ears, who cares what anyone else thinks?

So are we back ro the 70's again where low distortion only matters? I remember being young and naive back then and falling for this hype.

Never again.

You've missed the entire point of the discussion.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 10:34 pm
No one said the affects of inaudible things exerted with audible ones are inaudible. We don't understand it, but it seems to happen.

Also our measurement for audible is based on detection, but given the massive amount of information (terabytes) we might hear and not know it. It's possible maybe mood changes could be detected or something, even when the person can't tell you they hear a noise.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: *Scotty* on 26 Oct 2013, 10:38 pm
Which is the more important criteria to base a decision to buy an amp on? How the amp measures or how the amp sounds?
While the Ncore 400 was designed to be a "neutral" sounding amplifier, neutrality is only a good starting point. Once this goal has been achieved additional performance parameters need to addressed, such as the preservation of dynamic contrast, the height, width and depth of the sound-stage, depth layering within the sound-stage, three dimensionality of the sound-stage,(ie does the amplifier image in front of the plane of the speakers as well behind the speakers). The foregoing was obviously an incomplete list of subjective amplifier characteristics.
 Any or all of the above subjective parameters can be affected by the choice of passive parts as well as the active circuit design. To debate the audibility of a change in the sound of the amplifier based whether there was a change in a measurement is rather pointless. Especially considering that the amplifier was primarily designed to meet a subjective goal based on how it sounded to the designer..
The hobby is listening to music, an activity based on subjective experience, not reading objective specifications.
If one argues that a certain level of measured distortion THD, IM or what ever is well below the threshold of audibility and therefore could not impact what is heard, then you are very close to arguing that all amplifiers measuring below .05%THD will sound the same. Shades of  StereoReview and Julian Hirsch.
Scotty
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 26 Oct 2013, 10:42 pm
You've missed the entire point of the discussion.

Not really. Months ago I asked you how your low distortion figures translate into the quality of sound stage and transparency. I have heard other neutral amps that has more of those features in my system. But maybe the right mod can improve that on the Ncores.

Isn't that is what this is all about?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 10:50 pm
No one said the affects of inaudible things exerted with audible ones are inaudible. We don't understand it, but it seems to happen.

Also our measurement for audible is based on detection, but given the massive amount of information (terabytes) we might hear and not know it. It's possible maybe mood changes could be detected or something, even when the person can't tell you they hear a noise.

Sorry, but I really can't make heads nor tails of what you are saying here....
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 10:51 pm
Which is the more important criteria to base a decision to buy an amp on? How the amp measures or how the amp sounds?
While the Ncore 400 was designed to be a "neutral" sounding amplifier, neutrality is only a good starting point. Once this goal has been achieved additional performance parameters need to addressed, such as the preservation of dynamic contrast, the height, width and depth of the sound-stage, depth layering within the sound-stage, three dimensionality of the sound-stage,(ie does the amplifier image in front of the plane of the speakers as well behind the speakers). The foregoing was obviously an incomplete list of subjective amplifier characteristics.
 Any or all of the above subjective parameters can be affected by the choice of passive parts as well as the active circuit design. To debate the audibility of a change in the sound of the amplifier based whether there was a change in a measurement is rather pointless. Especially considering that the amplifier was primarily designed to meet a subjective goal based on how it sounded to the designer..
The hobby is listening to music, an activity based on subjective experience, not reading objective specifications.
If one argues that a certain level of measured distortion THD, IM or what ever is well below the threshold of audibility and therefore could not impact what is heard, then you are very close to arguing that all amplifiers measuring below .05%THD will sound the same. Shades of  StereoReview and Julian Hirsch.
Scotty

Debating subjective parameters is even more pointless.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 10:52 pm
Not really. Months ago I asked you how your low distortion figures translate into the quality of sound stage and transparency. I have heard other neutral amps that has more of those features in my system. But maybe the right mod can improve that on the Ncores.

Isn't that is what this is all about?

No, that's not what this is all about.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 26 Oct 2013, 11:05 pm
No, that's not what this is all about.

 :duh:
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: *Scotty* on 26 Oct 2013, 11:13 pm
A good first step, based on the posted listening impressions of the NC1200, would be to install into the NC400, as many of the passive parts used in the NC1200 as practically possible. Starting with the 12ga. wiring harness used in the NC1200.
Scotty
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 26 Oct 2013, 11:24 pm
Humans appear to be able to differentiate music with different types of noise/distortion that on an analyzing device have such a low volume that we are baffled as to why.

I can only offer speculation. Like we don't know we hear it, but it affects us subconsciously and we need ques to know it, some association. Perhaps it is a mechanical affect that occurs with speakers and feedback or something. I don't know. But I know the lower the noise/distortion seems to pay off. That's why I care about power conditioning so much, no matter how good you think your mains are (not the only source of noise).
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 11:32 pm
A good first step, based on the posted listening impressions of the NC1200, would be to install into the NC400, as many of the passive parts used in the NC1200 as practically possible. Starting with the 12ga. wiring harness used in the NC1200.
Scotty

So you are certain that these listening "impressions" are objective fact that resulted from the differences in passive parts, and have nothing to do with subjective factors on the part of the listeners, the room, the speakers, the other components, or the amp-system interactions?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 26 Oct 2013, 11:34 pm
But I know the lower the noise/distortion seems to pay off.


Well you better ask OzarkTom about that as he knows that the low distortion debate was settled in the '70's....
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: *Scotty* on 27 Oct 2013, 12:31 am
Quote from cab at 06:51PM
Quote
Debating subjective parameters is even more pointless.
Discussing subjective impressions of an amplifier is not pointless. See link: http://www.audiocircle.com/index.php?topic=105310.0
Ironic, considering that most people chose audio equipment based on how it sounds to them.
Quote from cab at  07:32 pm
Quote
So you are certain that these listening "impressions" are objective fact that resulted from the differences in passive parts, and have nothing to do with subjective factors on the part of the listeners, the room, the speakers, the other components, or the amp-system interactions?
Yes.
Scotty
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 27 Oct 2013, 12:35 am
Well you better ask OzarkTom about that as he knows that the low distortion debate was settled in the '70's....

It's not either or, Tom is saying you have to find something you like the sound of first, and it may not be the lowest in distortion. That doesn't mean taking your not lowest distortion device and plugging it into a conditioner or modifying it is invaluable.

Also if 90% of people subjectively prefer something, you might want to think about it.

Subjectivity is just objectivity we can't define.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 27 Oct 2013, 12:46 am
Quote from cab at 06:51PMDiscussing subjective impressions of an amplifier is not pointless. See link: http://www.audiocircle.com/index.php?topic=105310.0
Ironic, considering that most people chose audio equipment based on how it sounds to them.
Quote from cab at  07:32 pmYes.
Scotty



Subjective impressions I take with a grain of salt.

I won't even attempt to ask for any evidence of this.....there is no arguing religion.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 27 Oct 2013, 12:51 am
Well you better ask OzarkTom about that as he knows that the low distortion debate was settled in the '70's....

The only conclusion anyone could make back then was a highly distorted stock Dynaco ST-70 sounded much better and a Frank Van Alstine modded ST-70 sounded tons better. Unfortunately, I never bought a ST-70 in the 70's.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 27 Oct 2013, 01:07 am
It's not either or, Tom is saying you have to find something you like the sound of first, and it may not be the lowest in distortion. That doesn't mean taking your not lowest distortion device and plugging it into a conditioner or modifying it is invaluable.

Also if 90% of people subjectively prefer something, you might want to think about it.

Subjectivity is just objectivity we can't define.

My argument is first about the validity of subjective listening impressions- do they necessarily imply an objective improvement in amp performance, or as I have asserted, can people think something sounds "better" when in fact, it simply sounds different. You can't tell me with a straight face that without measurements you can make this distinction.

Secondly, if you can't define it, you can't measure it. See the first part of the argument.

Thirdly,  it is indeed about personal preferences- if one, or a thousand people think something "sounds better", does than mean that I will? No. That means that when someone tells me that this cap tweak improved the ncore, unless they can show me an objective improvement, it means nothing to me because odds are, it just sounds different. Maybe I will like it, maybe not. You can't call it an improvement, all you can say is it's a modification that was found preferable to stock. And, as I have said repeatedly, there is nothing wrong with that.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 27 Oct 2013, 01:10 am
My argument is first about the validity of subjective listening impressions- do they necessarily imply an objective improvement in amp performance, or as I have asserted, can people think something sounds "better" when in fact, it simply sounds different. You can't tell me with a straight face that without measurements you can make this distinction.

Secondly, if you can't define it, you can't measure it. See the first part of the argument.

Thirdly,  it is indeed about personal preferences- if one, or a thousand people think something "sounds better", does than mean that I will? No. That means that when someone tells me that this cap tweak improved the ncore, unless they can show me an objective improvement, it means nothing to me because odds are, it just sounds different. Maybe I will like it, maybe not. You can't call it an improvement, all you can say is it's a modification that was found preferable to stock. And, as I have said repeatedly, there is nothing wrong with that.
According to my measurement, this is truly the perfect post.   :thumb:
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 27 Oct 2013, 01:46 am
From a perspective of goals for an amplifier, it is an objective improvement if you increase the amount of capacitors. That isn't in question. The question is, does it matter to the ear, and could the ear measure it.

Objectively, from purely an engineering perspective that had the goal to have low noise/distortion, it is an improvement. You don't need to even bother to measure it because point blank as Occam put it, it's simple algebra.

You need to separate out the different things you that thinking about. You keep creating linear points that don't work with each other.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 27 Oct 2013, 03:17 am
You need to separate theory from practice....In theory yes, adding caps might add up to better measured performance. in a class d amp trace lengths, paths, and lead lengths can have a huge effect. Bruno has said that changes that can have a serious impact are measured in millimeters. How can you tell me that piggybacking caps on top of each other with the long leads, like in this mod, have not had any such effect on performance without measurements? Simply saying, "because it sounds better" is meaningless- there are amps with large amounts of distortion that some people find enjoyable, so that is no indication you have improved the objective performance.

And let's say that yes, these additional caps have been implemented in a benign way such that they actually do improve the objective performance in some way. How can you say that this improvement is large enough to be audible without measurement? How can you say this improvement is audible if the performance is already at the point where measured distortion is below the limits of human hearing? If you say, "there are things we can't measure", then I will say again, if you can't measure it then you can't know if it is an objective improvement or a mod you find subjectively pleasing.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 27 Oct 2013, 04:02 am
Again seems to me that logically this is a pretty cheap upgrade, yet not that critical to go this deep.

I have seen debates on several other types of upgrades that cost hundreds or thousands, at least this unit is virtually nothing to do the change and find the results.



I bet it would void the warranty. I wouldn't call that cheap if you need repair/replacement at some point.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 27 Oct 2013, 04:36 am
Doubling the capacitors changes the ESR/ESL value of the filter's capacitance. It's not subjective, and it is measurable. And it does increase a goal of the amplifier. Is it worth it, that's the question since all know physics to humans tells us exactly what I said. It's not disputed information, like said people have been doing it forever.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 27 Oct 2013, 08:52 am
given the massive amount of information (terabytes) we might hear

As you have mentioned the "terabytes" multiple times, I can't help wondering what that is based on.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 27 Oct 2013, 08:55 am
Doubling the capacitors changes the ESR/ESL value of the filter's capacitance. It's not subjective, and it is measurable. And it does increase a goal of the amplifier. Is it worth it, that's the question since all know physics to humans tells us exactly what I said. It's not disputed information, like said people have been doing it forever.

As cab mentioned, doubling the capacitors also changes the parasitic effects, and increasing the length of the leads definitely change things in a negative direction. How do you know that the supposed benefits of doubling the caps aren't dwarfed by negative effects?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 27 Oct 2013, 01:08 pm
Doubling the capacitors changes the ESR/ESL value of the filter's capacitance. It's not subjective, and it is measurable. And it does increase a goal of the amplifier. Is it worth it, that's the question since all know physics to humans tells us exactly what I said. It's not disputed information, like said people have been doing it forever.

What Julf said....Do you understand parasitics and their effects in class d? RFI/EMI issues and layout in class d? I think you missed the point I made above about theory and practice. And you have ignored the point about the possible improvements being potentially inaudible.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 27 Oct 2013, 04:13 pm
You are propsoing that a filter that includes the frequency range of possible mentioned interferance, and yet  halfs the noise to the output, could be a concern? Maybe if the leads could increase RFI three times.

Given that there is no concer for integrity of signal within this filter the differences of milimeters means so very little. Within the rest of the amplifier and characteristics of parts that carry signal, I am sure it is a huge concern.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 27 Oct 2013, 04:20 pm
Again, this is all speculation and opinion. Like I and others have said, end the speculation and ask Bruno yourself. There is nothing more to say.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 28 Oct 2013, 10:03 pm
(http://www.audiocircle.com/image.php?id=89012)
Things are not always as they appear.  I assumed all the .68 caps were oriented the same way.  I am just now doing my first mod using all .33 modded Wimas and just now realized that the caps in the middle are turned around.  At least they should be.....meaning....the ground is on the inductor side on the outside pair of caps but the middle cap has the ground pointing towards the ourside of the module.  So, no one has heard the totality of this mod yet.  The only person who has tried it has the middle set of caps backwards.  It will be interesting to hear his findings if he turns them around (so the outside foil is now to ground like all the other two stacks).  It may not make much difference since most are in the correct direction....but who knows?....except those that listen....they are the only ones that know.

#7 times infinity!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 28 Oct 2013, 10:14 pm
Here's my prediction: veils will be lifted, the soundstage will fill the room, and he will stay up all night playing his entire music collection, hearing things he has never heard before....
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 28 Oct 2013, 10:15 pm
Here's my prediction: veils will be lifted, the soundstage will fill the room, and he will stay up all night playing his entire music collection, hearing things he has never heard before....
:lol:


Where are the measurements?  Oh, that's right, can't do that.   :duh:
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 28 Oct 2013, 10:17 pm
I put #7 times infinity.  That means all objectivists concerns are already considered and heard and are already disregarded....he he.

The most "predictable" thing is what you guys always say.  Its always the same.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 28 Oct 2013, 11:19 pm
The most "predictable" thing is what you guys always say.  Its always the same.

Yeah, of course, it's called a conditioned response.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 29 Oct 2013, 06:46 am
except those that listen....they are the only ones that know.

I totally agree. Only the ones who listen, under controlled, double blind conditions, will know.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Rclark on 29 Oct 2013, 08:22 am
Modding the caps on an nc400. Isn't that a bit like trying wooden carriage wheels on an F1 car?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 29 Oct 2013, 11:08 am
Modding the caps on an nc400. Isn't that a bit like trying wooden carriage wheels on an F1 car?
No, it's like bringing the F1 car to the local tire store for tires after "the team" has handed you a track ready car.   :duh:
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 29 Oct 2013, 12:49 pm
No, it's like bringing the F1 car to the local tire store for tires after "the team" has handed you a track ready car.   :duh:

No, it's like bringing the engine from the F1 car to the local mechanic for a tune up after the engine building team has just finished tuning it....
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 30 Oct 2013, 01:44 am
Its a grand meeting of the objectivists....how perfect.

Why don't you take your act over to the tube tweakers forums....that would be funny.  You guys would be laughed right off the forum.  All those guys talk about is what brand of tube, cap, resistor, wire, tube socket, etc. to use to make the amp "sound" a certain way.  Of course, on this forum we have the perfect amp that has .0001 percent distortion, one milliohm output impedance and over 120db dynamic range.....so, therefore it is perfect.....he he.  Of course, everyone who has heard the NC1200 (which measures the same) says it sounds better in every way.  And now you have Bruno using "better sounding caps" in the Mola Mola amps....oh God, what are you guys going to do?  The NC400 is perfect, but the NC1200 is more perfect? and the Mola Mola with Bruno approved caps is even more perfect?  That simply cannot be!!!.....the NC400 is absolutely perfect and we all know it.  he he.

No, its like taking a stock BMW to your local hot rod place and making it do 50 more horsepower and put on better tires and fix the suspension and remove the steering wheel with air bag and use a tiny steering wheel and put a Recaro seat in it.  Hmmmm....exactly what a friend of mine did.  He said it was so fast around corners after that it scared him to death.  I guess you guys are scared of really burning rubber.  When I was a teenager we used to go down to Colorado Blvd. in Pasadena and yell "stocker" at passing cars.  Guys would feel so insulted they would turn around and chase you down to pound you into the ground.  I guess you guys don't mind being called "stockers".  Enjoy your stock "perfect" equipment.  But if its so perfect, why do you keep coming here to bother people?  I mean.....you have reached heaven.  Play those harps boys!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Rclark on 30 Oct 2013, 02:33 am
That's not it. We're saying it's far more likely with this tech that it's the design here that is not fundamentally reliant on caps, such as an older technology. The NC1200 might sound better for a variety of reasons but I highly highly doubt that caps chosen are a main factor at all.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 30 Oct 2013, 02:40 am
No, its like taking a stock BMW to your local hot rod place and making it do 50 more horsepower and put on better tires and fix the suspension and remove the steering wheel with air bag and use a tiny steering wheel and put a Recaro seat in it.
50 more horsepower? ... what a nonsens!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 30 Oct 2013, 03:17 am
That's not it. We're saying it's far more likely with this tech that it's the design here that is not fundamentally reliant on caps, such as an older technology. The NC1200 might sound better for a variety of reasons but I highly highly doubt that caps chosen are a main factor at all.

Rclark:  I would tend to agree, except that Mola Mola specifically notes the output filter capacitors…  Personally, I would suspect that the unique (completely different from that in the OEM NC-1200 module) input stage would be more responsible for the sound quality of the Mola Mola amplifiers.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 30 Oct 2013, 03:25 am
Sorry, the passive filter on the output of a class D amp literally defines the level of transparency that can come through.  This includes the inductor, of course.  Everything has a sound.  Sorry but true.  No free lunch here.  I changed the inductor on the older Hypex modules to a custom litz wire wound donut.  Sounded better than the stock inductor.  The inductor that is in the Ncore is a litz inductor (look real close).  This is good!  Even a Zobel network on the output of any amp will add its sound.  I have changed these parts many times on amps with the better parts giving the better sound.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 30 Oct 2013, 03:25 am
No, it's like bringing the engine from the F1 car to the local mechanic for a tune up after the engine building team has just finished tuning it....

WRONG: the NC-400 modules are mass produced parts, not finely honed, totally custom, F1 engines.  NC-400 modules incorporate many compromises in parts quality, design, and manufacture in order to make them cost effective in the marketplace for consumers.
If one wants to make an accurate analogy between an F1 engine and an audio component, one is going to be considering cost no object designs produced in very limited quantities, without regard to costs: the Light Harmonic Da Vinci Dac comes to mind, but even that is produced in numbers far beyond those of F1 engines, and is for sale to consumers, unlike F1 engines.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Rclark on 30 Oct 2013, 03:27 am
Nc1200's are a $12,000 amp. Higher end caps, because, why not at that price. I just don't think caps are a fundamental reason for the performance of the nc1200, nor do I think putting fancy caps in an nc400 would make any improvements.

Changing caps in a tube amp or a big SS class A amp makes perfect sense, not here.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 30 Oct 2013, 03:47 am
Thinking something does not make it so.  What did the person who started this thread say?  He listened.  He A/Bed two different stereo modules.....one modded and one not.  What he said is truth....it is based on direct experience.  His truth.  If your truth is based on what you "think" then it is has no basis in reality....reality is what you experience.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Rclark on 30 Oct 2013, 04:52 am
That's fine, I just don't buy it.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 30 Oct 2013, 10:58 am
WRONG: the NC-400 modules are mass produced parts, not finely honed, totally custom, F1 engines.  NC-400 modules incorporate many compromises in parts quality, design, and manufacture in order to make them cost effective in the marketplace for consumers.
sure, the NC400 incorporates many compromises in parts quality, but Bruno has the outrageousness to call the NC400 a "no-compromise power amp module for audiophile DIY projects"???
Sorry, but i'll take Bruno's word anytime over yours!

Please tell me somthing: you made changes many times and you got "better" sound. "Better" compared to what? To some "objective reference" or to your personal liking?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 30 Oct 2013, 11:09 am
Of course, if you cannot afford it, you are going to deny it. The NC 1200's sounded quite a bit  better than Jason's NC400  tour amps going around in my system. So how many companies were using NC400's at RMAF rhis year? Zero? Why, if they are the best?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 30 Oct 2013, 11:49 am
The NC 1200's sounded quite a bit  better than Jason's NC400  tour amps ...
please expand "a bit better".
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 30 Oct 2013, 12:29 pm
please expand "a bit better".

Smoother, more open, and more holographic. And by quite a bit.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 30 Oct 2013, 12:47 pm
and you are sure that was like that on the recording and intended by the artist / recording engineers?
How can you be sure that it's not something "exagerated" by the amp you liked more (and therefor call it "better") as oposed to the other beeing "truer to the source"?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 30 Oct 2013, 12:50 pm
So how many companies were using NC400's at RMAF rhis year? Zero? Why, if they are the best?

The NC400 is intended for the hobbyist market, the 1200 for the OEM market, so the fact that OEM companies use the 1200 and not the 400 proves that the Hypex positioning strategy works, but nothing else.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 30 Oct 2013, 12:51 pm
Smoother, more open, and more holographic. And by quite a bit.

At least 17.5

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 30 Oct 2013, 12:53 pm
I have changed these parts many times on amps with the better parts giving the better sound.

Better or different? Please share your measurements on the ncore "improvements" that lead you to believe it is "better".

Otherwise, you are just selling an opinion, not fact.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 30 Oct 2013, 12:55 pm
The NC400 is intended for the hobbyist market, the 1200 for the OEM market, so the fact that OEM companies use the 1200 and not the 400 proves that the Hypex positioning strategy works, but nothing else.

In other words, it is impossible to market amps with the nc400. I thought the fact that they were only sold to hobbyists was well known, at least to all of those who post in every hypex thread. Guess that shows that there is still a lot of ignorance out there about ncore.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 30 Oct 2013, 01:22 pm
WRONG: the NC-400 modules are mass produced parts, not finely honed, totally custom, F1 engines.  NC-400 modules incorporate many compromises in parts quality, design, and manufacture in order to make them cost effective in the marketplace for consumers.
If one wants to make an accurate analogy between an F1 engine and an audio component, one is going to be considering cost no object designs produced in very limited quantities, without regard to costs: the Light Harmonic Da Vinci Dac comes to mind, but even that is produced in numbers far beyond those of F1 engines, and is for sale to consumers, unlike F1 engines.

You have missed the point. The ncore is a state of the art class d amp designed by perhaps the leading class d designer in the world. It's measured performance is second to none. It is well known among people in the know that class d amp design is different than class a or b amp design- much more difficult, demanding, and exacting, with layout requirements down to the millimeter, completely different than other amp classes. Hypex says it is a no-compromise amp. The specs confirm this.

Now along comes someone who has never designed a class d amp, who probably couldn't design a class d. He makes his living doing his self-professed "improvements" on other people's work. He doesn't produce any proof that his mods have improved the amp, only his opinion. I have no doubt it sounds different, maybe to some it will sound better. But to insist, without any evidence other than his subjective opinion, that he has somehow improved the ncore, I say prove it or it's just self-servicing marketing bs.

If he took your F1 engine and told you he increased its performance, would you take his word for it or want to take it to the dyno?

Could the ncore be improved on an objective basis? Sure, Would such improvements be audible? Unknown. Secondly, I would place my trust in any changes to someone who has a demonstrated expertise in class d design and the issues involved, not someone ignorant of class d design.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Toaster on 30 Oct 2013, 02:38 pm
Gentlemen, you are wasting your time. If you're enjoying yourselves, fair play, but you are simply talking past each other, since the paradigms you are using as your starting premises for discussion are not the same. The 'subjectivists' are trying to convince the 'objectivists' that their claims about sound quality are valid based on observation, without protocols or controls. 'Objectivists' will not accept this- it does not meet their criteria as valid evidence. On the other hand the 'objectivists' are trying to tell the 'subjectivists' that they are not hearing what they claim to- or at least that it is not necessarily repeatable or universally true. Obviously if a 'subjectivist' hears one amp as sounding better than another, or finds that one glass of wine tastes better than another they will accept this as evidence. If enough people hear or taste the same thing a concensus may emerge. 'Subjectivists' will not accept being told that their sense perceptions are faulty by 'objectivists'- for them the subjective listening experience is the point of the exercise. This mirrors different perspectives in social science, particularly between functionalism and interactionism in sociology. The real debate centres around what is considered acceptable and appropriate as evidence of phenomena and also what kind of questions are being asked about external (objective?) and internal (experiential?) reality, and (on that basis) what kind of phenomena are being studied. To have an actual discussion, rather than a shouting match, you would need to agree on fundementals first, and that isn't very likely. Just saying...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 30 Oct 2013, 02:57 pm
The real debate centres around what is considered acceptable and appropriate as evidence of phenomena and also what kind of questions are being asked about external (objective?) and internal (experiential?) reality, and (on that basis) what kind of phenomena are being studied.

Indeed. So for the engineer designing the equipment, the question is "What is the goal here - to produce a system that reproduces the original signal as faithfully as possible, or to produce a system that sounds as pleasant as possible to the majority of people?". Two very different goals.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 30 Oct 2013, 03:17 pm
sure, the NC400 incorporates many compromises in parts quality, but Bruno has the outrageousness to call the NC400 a "no-compromise power amp module for audiophile DIY projects"???
Sorry, but i'll take Bruno's word anytime over yours!

Please tell me somthing: you made changes many times and you got "better" sound. "Better" compared to what? To some "objective reference" or to your personal liking?

Hahaha, you funny Waver!  Answer this question if you please:  If you really believe that the Ncore modules are no compromise designs, and that Mr Putzeys truly believes that, how do you account for the 3x cost of the Mola Mola amplifiers made by Mr Putzey's own brand?  I am saying 3x cost, becasue if NC-400s were produced in a finished product the resulting pair of mono blocks would run around $4K or so...
Are you really suggesting that Mola Mola (Bruno Putzeys) is trying to rip off customers by offering amplifiers with no performance benefit (besides 6 dB headroom) for 3x the price?

While making changes to my own NC-400 based stereo amp, I make direct comparisons to my Pass Labs X-150.5, the 150.5 stays constant, hence I have a static reference for comparisons.  Without the static reference, it would be more difficult to make accurate conclusions regarding any changes.  Note, that the poster of this thread, compared stock NC-400 modules directly with his modded versions, rather than trying to compare by memory.

It seems therer are quite a few folks on this thread who want very badly to believe that NC-400 based amplifiers are perfect in all regards-this is delusional.  They are very good, and especially very good for the price of admission, but they are far from perfect.  If one wants to continue to believe that the NC-400 is perfect, I would suggest not visiting audiophile forums.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 30 Oct 2013, 03:35 pm
"Indeed. So for the engineer designing the equipment, the question is "What is the goal here - to produce a system that reproduces the original signal as faithfully as possible, or to produce a system that sounds as pleasant as possible to the majority of people?". Two very different goals."

Julf, I respect your POV, but there is more at work here than the above.  Standard sets of measurements such as those published at Hypex site do not completeley describe the (objective) performance of any amplifier.  Noise and/or distortion under steady state signals are not enough to understand what may happen in circuit with complex and widely varying signals.  Intermodulation tests with many different frequencies, and square wave tests at many different frequencies might be more illuminating as to what makes for differences in amplifier sound.
Personally, I am not talking about making an amplifier which sounds "prettier" (adding its own color).  I am talking about making an amplifier which produces sounds out of a loudspeaker which are closer to real music.
While I find the NC-400 sounds very good, it does have its shortcomings as well.  Images are somewhat hollow, they are well defined in a single plane, but lack in body.  In real music, the image does not lack in body.  Consider just a cello, in a moderate size room...
What I also wonder about, is why would any self declared objectivist think that THD measurements define amplifier performance?  My understanding is that DBT testing has confirmed that humans cannot distinguish between levels of THD <1%!  By that standard all contemporary solid state amplifiers would be perfect, and all sound the same.  If we accpet that any of these amps sound different, we also need to accept that distortion measurements do not account for the differences in amplifier sound.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 30 Oct 2013, 03:37 pm
If the NC-400 modules are no comproise in build quality, I guess all the resistors on there are matched to .01% tolerances, right???  And furthermore, they must be metal foil types for the highest level of precision, right?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 30 Oct 2013, 03:41 pm
Noise and/or distortion under steady state signals are not enough to understand what may happen in circuit with complex and widely varying signals.  Intermodulation tests with many different frequencies, and square wave tests at many different frequencies might be more illuminating as to what makes for differences in amplifier sound.

Agree. But then we are just debating the best way to measure, not the issue of "is the final arbiter some silly number, or my absolutely perfect ears".

Quote
While I find the NC-400 sounds very good, it does have its shortcomings as well.  Images are somewhat hollow, they are well defined in a single plane, but lack in body.

And what measurable parameter corresponds to "body"?

Quote
What I also wonder about, is why would any self declared objectivist think that THD measurements define amplifier performance?

Do they?

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 30 Oct 2013, 04:28 pm
Hahaha, you funny Waver!  Answer this question if you please:  If you really believe that the Ncore modules are no compromise designs, and that Mr Putzeys truly believes that, how do you account for the 3x cost of the Mola Mola amplifiers made by Mr Putzey's own brand?
so, in other words, you say Mr Putzeys is a liar when he calles the NC400 a "no-compromise power amp module for audiophile DIY projects"?

Btw, i have not made any comment at all about the ncores! I'm just trying to quantify/qualify statements like 'sounds better' or 'improved quality' ...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 30 Oct 2013, 04:34 pm
so, in other words, you say Mr Putzeys is a liar when he calles the NC400 a "no-compromise power amp module for audiophile DIY projects"?

Btw, i have not made any comment at all about the ncores! I'm just trying to quantify/qualify statements like 'sounds better' or 'improved quality' ...

I see, it appears that you have no answer to my question.  And please, do not put words in my mouth which I did not utter.  Only Mr Putzeys can answer that question.  I would like to hear his response re the performance of the Mola Mola mono blocks vs the NC-400...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 30 Oct 2013, 04:41 pm
your question is not for me to answer. Besides you're comparing a DIY module with a comercial product ...
But it's clear to me that you don't believe it, so i didn't put anything in you mouth ...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 30 Oct 2013, 04:47 pm
Julf: Exactly, the standard set of measurements are inadequate.  Given that few people have the gear to do even a good job at the standard measurement sets (and for Ncore that means an AP-2, nothing else is going to have nearly the resolution on standard tests as the Ncore itself), it is unlikely that the many posters here are going to have a way to make these measurements.
Nordost tried to come up with a new measurement paradigm a couple of years back, using actual music signals, and comparing the input to the output-but they were met with such resistance from people who said they were "wrong" when the measurements actually showed differences between cables and vibration control devices, that they appear to have given up the pursuit, or perhaps they have decided to only use these measurements internally.

As to what measurement might be associated with "body" (and to be clear I was referring to body of a single image in space), I do not have the faintest idea what that might be, and neither do I need to measure it as listening is entirely adequate for me to note these differences.  For those who do need measurements, it is up to them to figure out what they will need to measure: my hint would be to look for problems in the time domain.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 30 Oct 2013, 04:50 pm
What's wrong with these (http://www.audiocircle.com/index.php?topic=108951.0)?  Done by a member here on AC.


Julf: Exactly, the standard set of measurements are inadequate.  Given that few people have the gear to do even a good job at the standard measurement sets (and for Ncore that means an AP-2, nothing else is going to have nearly the resolution on standard tests as the Ncore itself), it is unlikely that the many posters here are going to have a way to make these measurements.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 30 Oct 2013, 04:52 pm
And these. (http://www.audiocircle.com/index.php?topic=107040.0)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 30 Oct 2013, 04:53 pm
While making changes to my own NC-400 based stereo amp, I make direct comparisons to my Pass Labs X-150.5, the 150.5 stays constant, hence I have a static reference for comparisons.  Without the static reference, it would be more difficult to make accurate conclusions regarding any changes.  Note, that the poster of this thread, compared stock NC-400 modules directly with his modded versions, rather than trying to compare by memory.
making comparisions with another amp doesn't make an amp better or worse than the other, it's only you that like one better than the other. It says nothing about the amp itself.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 30 Oct 2013, 04:56 pm
What I also wonder about, is why would any self declared objectivist think that THD measurements define amplifier performance?
what i also wonder about is why all self declared subjectivists declare themselfs fully capable of discerning that one amp is 'better' than the other - yes there might be a difference, but at this level i doubt that a human is able to discerne that the change is for the 'better' and not accounting his personal preferences!

PS. just to be clear, i don't think that THD defines performance!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 30 Oct 2013, 08:36 pm
It seems therer are quite a few folks on this thread who want very badly to believe that NC-400 based amplifiers are perfect in all regards - this is delusional. They are very good, and especially very good for the price of admission, but they are far from perfect.
sorry to disappoint you, can't remember reading here that the NC400 is perfect!
But i have a hard time to believe that simply changing few capacitors will "greatly improve the sound", "the sound is more open", "the highs are significantly more detailed, vocals more etched and lifelike the bass has good weight but sounds more defined."

Now, you answer this question if you please: what could keep Bruno from using these capacitors in the first place (if all these improvements would be so obvious and true)?
The price of these few capacitors? I highly doubt it!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 30 Oct 2013, 09:58 pm
People here do indeed keep talking past one another.

I have never said the ncore is perfect, beyond improvement, or "the best". I have never said that modding the ncore won't result in an amp that sounds better to the modder.

I have never said that measurements determine the perception of an amp's sound.

What I have said repeatedly, though several readers seem to have trouble grasping the concept, is that without measurements, you can't say if your mod is an improvement in an objective, absolute sense. All you can say is that you prefer the new sound. It may indeed have improved the performance. Without any measurements, we have no idea if it is real improvement in performance or simply perception. How can anyone dispute this with a straight face?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 30 Oct 2013, 10:37 pm
I don't believe you can measure openness, detail, transparency, and holographic imaging by a measurement, only by the human ear.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 30 Oct 2013, 10:47 pm
I don't believe you can measure openness, detail, transparency, and holographic imaging by a measurement, only by the human ear.

Perhaps because those are all subjective and are open to interpretation. Like I said, if you can't measure it, you can't prove a performance improvement. All you have done is changed it, maybe for the better, maybe for the worse. There is no way to know without a set of before and after measurements. You may like it better, but that doesn't mean you have improved it.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 30 Oct 2013, 10:54 pm
4 Realities:

1.  The belief in objectivity (measurements)
2.  The ability to pull it off (technical know how and talent and perserverance)

3.  The belief in subjectivity (that all things sound different and you can hear them and know what is better sound and remember without blind tests)
4.  The ability to pull it off (years of listening tests on tweaky systems with heart and mind and ears open)

Let's say you quantify each of the above with a zero to 100 score.  I would say Bruno is 100% of number one....at least 90% of number 2......but what about 3 and 4?  Does he really believe that all things sound different?  Has he spent hours and hours doing listening tests to different brands of resistors, wires, solder, caps, damping methods, grounding methods, circuit designs, removing LEDs, removing steel plates from transformers, etc. etc.?  Has he taken Wima polyprop caps and ground off the ends and attached his own Wonder Solder signature tinned 6N copper wires and marked the caps for outside foil and done a listening test?  Not hardly.  The guy is making a fortune selling amps to all kinds of manufacturers (I bet mostly to sub amp people and the pro market).  He does not have time for such things.  He is designing all kinds of things right now.  He want to be successful (make a lot of money). 

I emailed Nelson Pass a few months ago about the fact that I was going to mod his First Watt amps and I told him I would help him with tweaking his products and even do it for cheap or free.  He replied that what I do is valid but "he has no interest in it".  He is making great money doing what he wants (circuit design) and has no interest in going down the long tunnel of tweakdom.  You see.....tweaking is like life....it is infinite....an infinite Pandoras box....yup.  You will never get to the end.  You will never reach "perfection".  Once you do a few straight wire bypass tests and realize that even a small piece of wire is audible....well....you realize that the game is never ending.  The objectivists live in a simple world.  I envy such simplicity.  Nelson had no problem with me playing with or modding his gear.  He does not resist tweaking........he just has no interest in it.

You realize that it has never been proven that lower measured distortion actually brings better sound (amps and preamps, not speakers).  No double blind test has ever showed that anything below .1 percent distortion is audible.  So, what is all this about measurements?  Why not use a 1975 Kenwood integrated amp?  Some of the most revered amps currently are the DiAgostino amps and the Dartzeel amps.  These both have no overall feedback and measure like it (highish distortion and highish output impedance).....but people LOVE how they sound.  What is real?  What is really neutral?  What is really transparent?  Only your ears will tell you.  Please try a straight wire bypass test on your Ncore or whatever.....it is possible to do.  Then you will see how transparent it really is or isn't.

Most things that change the sound are not measureable.  This is the truth.  Changing the caps will not change the measurements.  Using better wire, better damping, better jacks, better fuses, etc. etc. will not change any measurement whatsoever......but it does change the sound. 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 30 Oct 2013, 11:05 pm
but it does change the sound.

No one said it doesn't change the sound. What has been said is that the change, without measurement, can not be said to be an improvement, only a change. A change some people might find agreeable, some not. Your preferences are not universal.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 30 Oct 2013, 11:19 pm
Do all audiophiles a favor cab, never become an audio reviewer.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 30 Oct 2013, 11:22 pm
At least 17.5

Wow, you must have ESPN or something. You are correct.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Rclark on 30 Oct 2013, 11:28 pm
I would greatly trust Cab's impressions on gear. No ground unicorn horn or fairy dust in his appraisals.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 30 Oct 2013, 11:33 pm
The funny thing is that usually a big increase in desired traits is really obvious to all listener, while we lack words for it consensus is pretty easy to achieve. In fact so much so that people read reviews of equipment and find the word of learned-to-trust reviewers to be as good as objective data. I shit you not, outside of this website there are entire magazines and other websites dedicated to this obviously philosophical flop. Sadly a profound oppression of incoming money keeps these dishonest instituitions on every magazine rack and search engine.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 30 Oct 2013, 11:38 pm
Do all audiophiles a favor cab, never become an audio reviewer.

Don't worry, I wouldn't dream that my personal preferences mean anything to anyone but myself.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 30 Oct 2013, 11:43 pm
The funny thing is that usually a big increase in desired traits is really obvious to all listener, while we lack words for it consensus is pretty easy to achieve. In fact so much so that people read reviews of equipment and find the word of learned-to-trust reviewers to be as good as objective data.

No, it can also mean that certain people have similar likes. Find a reviewer that has similar likes, and maybe you can learn to trust their opinion. Doesn't mean it applies to everyone. How many times have people read a review and scratched their heads after hearing the equipment?

The fact that there are so many different makers of equipment means there are many differing opinions on what sounds "best". Look at all the differing opinions on rooms at audio shows.

The only opinion that matters is your own. If it works for you, great. Just don't tell me it will work for me.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 30 Oct 2013, 11:48 pm
No one said it doesn't change the sound. What has been said is that the change, without measurement, can not be said to be an improvement, only a change. A change some people might find agreeable, some not. Your preferences are not universal.

Cab: your statement is not true.  Here is why:  Take amplifier A (unmodded NC-400 amp) and amplifier B (identical NC-400, except with the cap mod described here).  Now, listen to a cello playing in your listening room, and at the same time capture the playback at 24/192, DSD 128, or whatever you prefer.
Now playback and compare the sound of the two amps, with the live cello sound as your reference.  Whichever amp sounds closer to the real thing is better, not just different.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 30 Oct 2013, 11:57 pm
Cab: your statement is not true.  Here is why:  Take amplifier A (unmodded NC-400 amp) and amplifier B (identical NC-400, except with the cap mod described here).  Now, listen to a cello playing in your listening room, and at the same time capture the playback at 24/192, DSD 128, or whatever you prefer.
Now playback and compare the sound of the two amps, with the live cello sound as your reference.  Whichever amp sounds closer to the real thing is better, not just different.


Interesting.  Then can you explain this to us?  What don't you like about it?


Ted: I really do not feel like I should comment further here.  There is plenty of information on the Amenero USB interface at diyaudio.com for those who would like to learn more.Personally, I feel the USB interface is a critical part of any DAC where the primary playback is going to be from a computer/server source, and there are big differences in the performance of different USB interfaces.It sure would be nice if all Async USB interfaces were equal, but that is surely not the case.  A USB interface can be a stumbling block for many manufacturers, especially smaller ones, who do not have the resources (computer engineers comfortable with high speed data design and programming) to develop and perfect their own interface.  Even the popular XMOS chip requires quite a bit of specialized skills to be implemented well.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 31 Oct 2013, 12:12 am
Cab: your statement is not true.  Here is why:  Take amplifier A (unmodded NC-400 amp) and amplifier B (identical NC-400, except with the cap mod described here).  Now, listen to a cello playing in your listening room, and at the same time capture the playback at 24/192, DSD 128, or whatever you prefer.
Now playback and compare the sound of the two amps, with the live cello sound as your reference.  Whichever amp sounds closer to the real thing is better, not just different.

No, it is true. Not everyone will agree on which amp is "better", it is subjective, therefore, different.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 31 Oct 2013, 12:22 am
Cab: your statement is not true.  Here is why:  Take amplifier A (unmodded NC-400 amp) and amplifier B (identical NC-400, except with the cap mod described here).  Now, listen to a cello playing in your listening room, and at the same time capture the playback at 24/192, DSD 128, or whatever you prefer.
Now playback and compare the sound of the two amps, with the live cello sound as your reference.  Whichever amp sounds closer to the real thing is better, not just different.
gotcha: you have no ideea how the cello really sounded as you were not in the room where the recordings (you use for testing) were done! And guess what, not all cellos sound the same, in case you compare it to the cello you might have in the room, as your (listening) room will color the sound of the cello in a different way that the recording room has done.
And there's one more thing: picking up the cello with microphone A will sound different from picking it up with microphone B. Enter the recording engineer that processes the recording, changing the sound of the cello to his liking.

So, what do you compare the sound of the cello from the recordings with, when you don't know how it really sounded originally?
And if you try to compare it with the sound from the concert last week, may i ask do you compare the sound of the cello listened from the first row middle, seventh row middle or the sound of the cello where the microphones were placed?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Folsom on 31 Oct 2013, 01:33 am
No, it can also mean that certain people have similar likes. Find a reviewer that has similar likes, and maybe you can learn to trust their opinion. Doesn't mean it applies to everyone. How many times have people read a review and scratched their heads after hearing the equipment?

The fact that there are so many different makers of equipment means there are many differing opinions on what sounds "best". Look at all the differing opinions on rooms at audio shows.

The only opinion that matters is your own. If it works for you, great. Just don't tell me it will work for me.

I'll write it again.

"Learned-to-trust" as in a combination word that becomes an adjective; describing a someone/thing that someone had learned (gained experiances that set in information to their brain) to trust (believing that whatever potential is suggested by, is reasonable)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 31 Oct 2013, 04:21 am
gotcha: you have no ideea how the cello really sounded as you were not in the room where the recordings (you use for testing) were done! And guess what, not all cellos sound the same, in case you compare it to the cello you might have in the room, as your (listening) room will color the sound of the cello in a different way that the recording room has done.
And there's one more thing: picking up the cello with microphone A will sound different from picking it up with microphone B. Enter the recording engineer that processes the recording, changing the sound of the cello to his liking.

So, what do you compare the sound of the cello from the recordings with, when you don't know how it really sounded originally?
And if you try to compare it with the sound from the concert last week, may i ask do you compare the sound of the cello listened from the first row middle, seventh row middle or the sound of the cello where the microphones were placed?

Read my statement again.  The example requires one to hear the cello playing during the recording session live in the room.  Yes, there will be small differences due to microphone choice, placement, etc, but anyone who has actual experience doing this kind of test will hear much larger differences between the live sound, and the playback sound.  Unfortunately, even high end audio systems are very far from sounding the same as the real thing.
So far, from what I am hearing here-it appears that folks calling themselves objectivists actually choose all their audio components based on measurements alone?!!  Really?  I have heard some awful sounding amplifiers with fantastic measurements, and yes, I am quite confident that the amplifiers I am referring to were bad, not just different.  Now I have nothing against measurements, indeed they are necessary to confirm that nothing is grossly wrong and that the circuit is behaving as expected-but there is no respectable audio engineer which I am aware of which does not also rely on listening (including Bruno Putzeys).
It is too bad that so may here seem to have little experience remembering what a real instrument sounds like, and being able to evaluate systems/components via a real reference.
I am done with this thread, as there is no further point to spending time here.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: farquad on 31 Oct 2013, 06:09 am

I emailed Nelson Pass a few months ago about the fact that I was going to mod his First Watt amps and I told him I would help him with tweaking his products and even do it for cheap or free.  He replied that what I do is valid but "he has no interest in it".  He is making great money doing what he wants (circuit design) and has no interest in going down the long tunnel of tweakdom.  You see.....tweaking is like life....it is infinite....an infinite Pandoras box....yup.  You will never get to the end.  You will never reach "perfection".  Once you do a few straight wire bypass tests and realize that even a small piece of wire is audible....well....you realize that the game is never ending.  The objectivists live in a simple world.  I envy such simplicity.  Nelson had no problem with me playing with or modding his gear.  He does not resist tweaking........he just has no interest in it.
It seams mr pass is a very polite man. Giving you such a polite answer. You practicly told him you could redo what he has done and then tell him how to do his job. I wonder why he declined.


You realize that it has never been proven that lower measured distortion actually brings better sound (amps and preamps, not speakers). 

You keep replying to posts which hasnt been posted.
Noone said low distortion, to a degree of 100%, equals better sound quality.
Low distortion measurement on its own says nothing about sound quality.
The thing with NCore is we already know it sounds great and it measures great.
So a measured improvement would most definately indicate an improvement in sound quality. If that sound quality is audible is another matter though.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 31 Oct 2013, 06:36 am
So far, from what I am hearing here-it appears that folks calling themselves objectivists actually choose all their audio components based on measurements alone?!!  Really?

No. Really. We just don't pretend what we happen to like is "better" in any absolute sense, and we don't assume other people necessarily agree with our tastes. What we are saying is that if you want to know if a change actually results in an improvement in an objective sense, measurements are essential. And measurements are much more than just distortion (that subjectivists seem hung up on).

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 31 Oct 2013, 07:59 am
12 pages of nothing! 

You either trust the direct experience of your being/mind and senses or you don't.  I trust what I experience.  It is beautiful.  You are beautiful.  Thoughts are like clouds....just drifting and changing....not really much there.  The beautiful truth is always waiting to be felt and known.  I wish you all wonderful joy and love.....for it is what we have come for.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 31 Oct 2013, 08:04 am
You either trust the direct experience of your being/mind and senses or you don't.

Exactly. You either acknowledge the imperfections (or maybe better call them "quirks" - the "imperfections" probably served us well during our evolutionary history as a species) or you don't.

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 31 Oct 2013, 08:18 am
What imperfections?  It is all perfect....yup...all of it...including the so called imperfections.  All I see is love.  All I am is love.  All you are is love.  Eternal infinite love.  Just as in audio truth (based on listening with our senses).....the truth of our being is experienced by directly listening to life with our hearts and minds totally open.  Practice makes perfection.  Please try to listen more.  You will be surprised by how glorious it all is.  Why practice when it is already perfect?  Because we have forgotten.....we must re-member ourselves.  We came to reclaim our glory!  Our Joy!  Our Happiness!  Oh Happy Day!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 31 Oct 2013, 12:38 pm
What imperfections?  It is all perfect....

So why mod? Oh, that's right, that's how you make your living.

I trust my hearing and perceptions. I just don't trust yours.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 31 Oct 2013, 12:44 pm
Read my statement again.  The example requires one to hear the cello playing during the recording session live in the room.  Yes, there will be small differences due to microphone choice, placement, etc, but anyone who has actual experience doing this kind of test will hear much larger differences between the live sound, and the playback sound.  Unfortunately, even high end audio systems are very far from sounding the same as the real thing.
Finally we agree, except for the microphone choice and placement that give rather big differences!

Now tell me, how many self declared subjectivists attended recording sessions of the recordings they use for testing?
I'll tell you: NONE! Never heard of studios complaining about too many atendees (audiophiles).
But lets pretend they were attending, it's mostly several years in the past. Do you really want me to believe that you (and them) have such a "perfect" memory, that you remember every detail (after years) and can compare it to the sound of the playing amp?  :o
And while comparing from memory you can account for the "much larger differences between the live sounds (back then) and the playback (today)", put your personal preference aside and quantify the much smaller difference between stock and modded NC400 and say which is "closer to the real thing"?
Sorry, but i don't believe it!

Let's keep it simple and say you like one better than the other and save all the BS about 'greatly improved sound' or 'significantly more details'.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 31 Oct 2013, 12:47 pm
Maybe PS Audio hired musicians to play for barrows & the design team so they could match their equipment sonically.   :rotflmao:
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 31 Oct 2013, 12:48 pm
No. Really. We just don't pretend what we happen to like is "better" in any absolute sense, and we don't assume other people necessarily agree with our tastes. What we are saying is that if you want to know if a change actually results in an improvement in an objective sense, measurements are essential. And measurements are much more than just distortion (that subjectivists seem hung up on).
+1
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 31 Oct 2013, 01:09 pm
No. Really. We just don't pretend what we happen to like is "better" in any absolute sense, and we don't assume other people necessarily agree with our tastes. What we are saying is that if you want to know if a change actually results in an improvement in an objective sense, measurements are essential. And measurements are much more than just distortion (that subjectivists seem hung up on).

that's it-exactly!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 31 Oct 2013, 01:55 pm
Funny how no one has bothered to ask Bruno his opinion.....
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Toaster on 31 Oct 2013, 02:02 pm
While the 'subjectivists' will groan, even though I tend to choose audio equipment based on what I think of the sound of it, limitations like expectation bias are a genuine issue. I also agree that comparing a modified amp to a fixed reference in a system context may not be useful. Using the example given, what if the recording of the cello really is lacking in 'body'? If an amp adds more 'body', this does not necessarily make it better- it may really be slightly worse but sound more like a real cello (or the listeners memories of real cellos) in that room, with that system, than it did before. But there is another side to the coin; experiential evidence has helped push developments in audio design and measurement techniques which have resulted in what many would regard as better sound and better engineering. Also, I have found that expectation bias is not quite as powerful and pervasive as is sometimes suggested. Just anecdotal I know, but I have listened to comparisons between pieces of hifi gear that have not gone at all as I expected. I have been surprised. Also, I have heard equipment that sounded so-so in one context sound excellent in another. So, while I respect those who are attempting to push the boundaries like Ric, I do have concerns about repeatability and consistancy. 'Context' is a really big deal in this context! I do worry that, even with the best intentions, it is easy to become involved with modifications and experiments to the extent that one is emotionally entangled with outcomes, to the potential detriment of accurate reporting. I'm not saying this is necessarily so, but it is a risk. There is a danger that if one is too sceptical, genuine and useful improvements might be ignored. Then again, 'subjectivists' need to be cautious about making pronouncements based on necessarily limited personal experiences as if (ironically?) they were objective.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Toaster on 31 Oct 2013, 02:16 pm
While I wouldn't presume to speak for Bruno, his response is really embodied in the amplifier itself. At some point, as a designer, you have to 'put the pen down' and call the design done. If he considers it to be a 'no-compromise' design, then he has done everything he thinks he can, that (in his view) makes a difference. Just because it is not someone else's idea of 'no-compromise' doesn't mean it isn't his at the point the design is completed. This doesn't preclude further improvements in the future. Knowledge can develop...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 31 Oct 2013, 07:04 pm
I do worry that, even with the best intentions, it is easy to become involved with modifications and experiments to the extent that one is emotionally entangled with outcomes, to the potential detriment of accurate reporting.

And then there are financial entanglements...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: bbest on 19 Nov 2013, 06:02 am
Hi guys!

Why you all wasting your time? Too many pages of "water". Who from you really tasted NC400 with or without tweaked PP caps? Please try to be more realistic against theorize. Ric Schultz you have did a great job. Thanks for sharing of your experience!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 1 Dec 2013, 06:00 am
Just been catching up on this post I started after being away awhile recladding my house. Work still in progress but over the hump.

Been an hilarious read catching up on things said, some just don't get it, if you haven't any real world experience your comments have no substance, my original post was aimed at people willing to make adjustment and speak for them selves.

I have adjusted my middle cap to face opposite to the caps each side, correctly facing the caps as Ric has specified, I'm extremely happy with the results, also PS Audio has made available a firmware release for the Perfect Wave DAC in tandem with the PS Audio WaveStream  software the Audio experience with my modified NC400 is the best I have heard. The audio experience allows me to easily feel as if I was there at the live recording. Before the recent mods this was not the case. :thumb:

If you haven't tried it how can you comment? If you base your opinion on anything other than real world experience, then your opinion has no basis for comment :nono: I want to hear from people with real experience. If you try the mod after having lived with the NC400 sound for a year+ then feel free to convey your personal experience on the resulting sound change :thumb:   

Cheers
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Rclark on 1 Dec 2013, 06:39 am
My guess is you're hearing things and need to spend a lengthy period of time with the mod. I just don't believe a cap change will "improve these amps". Change, yes. And change in these situations is always initially thought an improvement.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Rclark on 1 Dec 2013, 07:47 am
Hey everybody,  let's just be honest. You've had these amps in your system or you own these amps and you love these amps. Ncores kick ass, and have clearly audible superiority and power.

I have some other fairly high quality amps in my system and, or I've borrowed others.

Ncores are flat out amazing, period. I can't imagine not being heavily impressed by them, especially considering their size, efficiency, and the fact that even in a completely sealed chassis they never get more than slightly warm to the touch despite throwing Maggie panels around like ragdolls.

You all love these amps and you know it.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 1 Dec 2013, 02:27 pm
If you try the mod after having lived with the NC400 sound for a year+ then feel free to convey your personal experience on the resulting sound change :thumb:   

Cheers

No one has denied that there may be a sound change. What has been stated, and rightly so, is that there is no telling if this sound change will be perceived as an improvement by everyone, nor is there any proof that the amp has been objectively improved by the mod.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 1 Dec 2013, 02:32 pm
If you haven't tried it how can you comment? If you base your opinion on anything other than real world experience, then your opinion has no basis for comment :nono:
well, then let me ask you a question:

... the Audio experience with my modified NC400 is the best I have heard. The audio experience allows me to easily feel as if I was there at the live recording. Before the recent mods this was not the case. :thumb:
We all get it that you like the way the mod sounds. That's excellent and i am happy for you. Enjoy the wonderfull experiences of listening to music.

But how can you tell that with the mod it's like "at the live recording"?
I hate to repeat myself, but i don't beleive you were in the recording rooms when the recordings (you use for evaluation) were done! So you only assume it's "like at the live recording".
Now, if you base your comments on assumptions why am i not wellcome to comment?
I accept that you like the sound of the mod, that it's closer to you personal preference or to what you imagine would be the "perferct" reproduction, but i can't accept comments like 'improvement', 'natural', 'accurate', 'real' or 'like at the live recording' as you weren't in the recording room. period.
Sorry, but the more you repeat it the more your credibility goes down ...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 2 Dec 2013, 10:55 am
If you haven't tried it how can you comment?

I haven't actually tried jumping out of an airplane without a parachute, so how can I think and say it is a bad idea?
 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jackman on 2 Dec 2013, 05:16 pm
Guys, I'm not sure why everyone is giving this guy a hard time.  He made a modification and thinks it sounds better than the original.   These days people modify everything at every price point.  Heck, I believe there are people in this thread who own modded Magnepan speakers (Gunned) and I've never seen any evidence the Gunned Maggies measure better or sound better than the original.  If you like the results, more power to you .  How is this guy modifying an Ncore amp any different? 

I'm not going to modify mine because they sound pretty good as-is, and I don't want to mess up resale value if/when I decide to sell them.  Plus, I can't imagine soldering sufrace mounted components.  That's asking for problems...

Cheers,
J
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 2 Dec 2013, 05:20 pm
Nothing wrong in modding, and great if he enjoys it, but claims about the superiority of the mods are just that, claims, subject to debate.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jackman on 2 Dec 2013, 06:32 pm
Nothing wrong in modding, and great if he enjoys it, but claims about the superiority of the mods are just that, claims, subject to debate.

Come on, you know that 99.9% of all people who mod anything think it sounds better!  There is a guy (not on this thread and I'm not going to say his name) who makes minor changes to his system every few months and is "Blown away" by the massive improvement to his overall sound.  He also spends big bucks on things like Stillpoints for his speakers (something like $3k) and is rewarded by improvements beyond the imagination of the common man.  Every month the proverbial "veil" is lifted from his speakers and he is hearing music for the first time...until the next month or two when it happens again. 

The OP in this thread made a change and feels it sounds better.  I'd like to hear it but will not mod my amp because I want to sell it someday.  Hopefully some people can get together and do some blind listening. 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 2 Dec 2013, 06:44 pm
Every month the proverbial "veil" is lifted from his speakers and he is hearing music for the first time...until the next month or two when it happens again.

The Dance of the 1001 Veils? :)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: mjock3 on 9 Dec 2013, 02:29 am
Here is a great quote by someone well respected in the audio community. I thought I might share here:

"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: waver on 9 Dec 2013, 11:31 am
@mjock3,
you are missing the point!
No one here goes by the numbers and uses these numbers as a subtitute for human judgement.
As i said before, "appreciation of audio" leads you to say that you like your "subjective human experience" with the modded amp better than the "experience" with the stock amp. And that's perfectly fine - no one has ever doubted that part.

But comments like 'improvement', 'natural', 'accurate', 'real' or 'like at the live recording' are not subjective appreciations, they are absolute statements relating to some objective reference (eg. the live experience). And even more, these statements are mostly bolded by adjectives 'greatly', 'huge' etc.
How can anyone make such absolute statements not even beeing in the recording rooms where the recordings were done, meaning without having that 'objective reference = live experience'?
I find it even more strange that these statements are mostly made after listening in rooms that have barely acoustic treatement or none at all ...
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: mjock3 on 9 Dec 2013, 05:39 pm
@waver,

my comment was intended to comments like posts 16, 20, 27, 31 to name a few.  :)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 9 Dec 2013, 06:06 pm
@waver,

my comment was intended to comments like posts 16, 20, 27, 31 to name a few.  :)
Actually, your missing the point.
Title: Modded Maggies
Post by: EuroDriver on 9 Dec 2013, 06:32 pm
Heck, I believe there are people in this thread who own modded Magnepan speakers (Gunned) and I've never seen any evidence the Gunned Maggies measure better or sound better than the original. 

I modded my Maggie 1.6 QR with Hoveland caps and Alphacore copperfoil inductors.  I organized a group buy for the caps and inductors and 15 out of 17 participants were happy with the improvement.  There was nothing measureable in terms of frequency response, but boy could you hear the difference. 

Not that surprising as $ 12 Hovland caps were replacing 50 cent Solens and a $150 copper foil inductor was replacing a $10 iron cored inductor

No one has yet to measure the effects of burn in,  but most of us can hear it
Title: Re: Modded Maggies
Post by: Julf on 9 Dec 2013, 06:40 pm
No one has yet to measure the effects of burn in,  but most of us can hear it

It would be interesting to find out if people could hear burn-in before audiophile mags and forums started to talk about it.
Title: Power cord burn in story
Post by: EuroDriver on 9 Dec 2013, 07:30 pm
It would be interesting to find out if people could hear burn-in before audiophile mags and forums started to talk about it.

I recently borrowed two indentical fancy power cords from a local HiFi shop for a weekend trial.  These were put together by the shop using premium components.  I used them on the CD player and the power amp. One sounded pretty good, the other sounded terrible.  I could not believe the difference.  I marked the bad sounding cord with a piece of masking tape and took the two cables back to the shop, and told them my listening observations.

The shop owner explained, one cable had been burned in for 2 weeks, but the other had just been assembled the day before he lent it to me.

When I bought my Euro 500 speaker cables they took about 3 days of burn in to sound better than my Euro 70 cables and another 2 days of burn in before I could no longer detect any differences.  The speaker cable experience could be explained away by saying my ears and brain were adjusting over time, but there is no conceivable alternative explanation of why the direct AB comparison of two identical power cables was so different, especially on the CD player

40 years ago, I thought all the cables were the same, but my experience over the years has clearly been different
Title: Re: Power cord burn in story
Post by: Julf on 9 Dec 2013, 07:46 pm
40 years ago, I thought all the cables were the same, but my experience over the years has clearly been different

30 years ago, I thought cables were different, but my experience (mainly realizing the power of the "psycho" part of psychoacoustics) over the years has been different. And I am not being flippant.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: daveeigler on 10 Dec 2013, 05:41 am
Amazing. On other threads that statement would be called trolling. Get help!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 10 Dec 2013, 07:17 am
Amazing. On other threads that statement would be called trolling. Get help!

I am sorry you are having a bad day. I suggest you go an buy yourself some new cables, I am sure that will make you feel better.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: daveeigler on 10 Dec 2013, 08:11 am
Actually, I was having a great evening listening with my NC400 dual monos built by James Romeyn and cap mod with speaker cable mod done by Ric Shultz. Both gentlemen did a fabulous job. The sound is by far the best amp that has ever been in my house. I never did any measurements, my ears do not lie in this case. I just have a feeling I have more fun with my system/music than trying to prove with numbers it is better. Another tweak is to use EMI/RFI paper to cover SMPS portion of case. I also have mono blocks coupled to Symposium shelves with HRS Damping plates on top. Verastarr Grand Illusion (gotta love that one) power cords bring clean conditioned regulated power. Vinyl and digital sounds great through Harbeth P3ESR / Rel R305 sub speaker combo. I love using tweaks to get the best out of my equipment and room, an extension of this crazy hobby. Nothing personal, it is just your comments take the fun out of this thread, and that is all we are here for. Peace-out!
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 10 Dec 2013, 09:54 am
Nothing personal, it is just your comments take the fun out of this thread, and that is all we are here for.

Some of us find subjective tweaking fun. Others prefer to base their tweaking on scientific methods. Both can be fun.

Quote
I never did any measurements, my ears do not lie in this case

Then why does someone disagreeing with you spoil your fun? You believe your ears, I believe my own - verified by measuring instruments and controlled blind listening. We don't need (and probably won't) agree on what sounds good to us - and there is no need to, as long as we don't start making universal statements (such as "damping plates improve the sound").
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 10 Dec 2013, 02:10 pm
Hey Julf,  why does this topic bother you so much that you spend so much of your time here debating the mod? Start another thread on why only measurements matters and nothing else is relevant. I am sure you will get a few followers there.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 10 Dec 2013, 02:17 pm
Hey Julf,  why does this topic bother you so much that you spend so much of your time here debating the mod? Start another thread on why only measurements matters and nothing else is relevant. I am sure you will get a few followers there.

Hey OzarkTom, why does every ncore thread, despite not owning an ncore and having posted it wasn't for you, bother you so much that you spend so much of your time adding essentially nothing of substance to each and every thread?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 10 Dec 2013, 02:22 pm
Start another thread on why only measurements matters and nothing else is relevant. I am sure you will get a few followers there.

Measurements are a way of verifying/calibrating. What matters to me (if judging sound quality) is listening - but with my ears, not with my eyes or biases. What matters to you might be something entirely different.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: OzarkTom on 10 Dec 2013, 02:54 pm
Measurements are a way of verifying/calibrating. What matters to me (if judging sound quality) is listening - but with my ears, not with my eyes or biases. What matters to you might be something entirely different.

Then start a new thread saying that and leave this one alone.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 10 Dec 2013, 03:31 pm
Then start a new thread saying that and leave this one alone.

The OP asked for responses to the idea of the capacitor modification. He did not state that evidence-based responses were excluded. If an open and balanced discussion bothers you, you should probably ignore this thread.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: audio-heaven on 10 Dec 2013, 03:49 pm
This is an age old argument and I have yet to see any of them end well. Measurements are the most important thing 'up to a point', the Ncore's overall distortion is so low as to be inaudible to the human ear. The highest levels of distortion are always made by the speakers. I cannot agree with the view that nothing at all will effect's the performance of an amplifier. Or that science has an explanation for every phenomena that can be experienced by changing certain things in the audio chain. However I would always caution anyone against the 'modification' of a piece of electronics unless they know at least as much as the engineer that designed it.

The choice of a component by an engineer is not always determined by the necessity or desire to cut costs, there may be other very important reasons why they've carefully selected a part that we are unaware of.

It would seem that it's a part of human nature to 'always blame the new guy' when it comes to an apparent or perceived drop in performance. The countless times I've seen people say on audio forums - "I tried this new 'wonderamp' in my system and it sounded terrible, this thing has great reviews, really low distortion...... I just don't understand it"! The replies to this are usually "you tried it and you just didn't like it, send it back and try another" - and so it goes on. On the face of it that all sounds perfectly reasonable BUT not once have I ever seen anyone suggesting that the new amplifier is not poor at all, it's the rest of the system is not up to scratch. The new amp is only revealing the shortcomings that were previously masked by the lesser amp.

Why is that? After all that would explain the "good reviews" as well as the poor ones!

The point I am leading up to it that unless you are supremely confident that you have a 'well balanced' system and it is performing at the very best of it's ability it would be very unwise to tamper with the electronics. For starters you have no baseline to work from, all you will be doing is altering the sound and not necessarily for the better. Before judging an amplifier I would advise anyone to hear it coupled to the very best source and speakers you can possibly manage!

I own a pair of Ncore Monos and I've tried them out in quite a few different systems some better than others. Interestingly but rather unsurprisingly they always sounded great in the better systems.

Confession time: One thing I will say ~ and this bugs the hell out of me because it should not exist. I have always noticed a very real and dramatic improvement in SQ when some serious anti vibration control is used. Why this should effect solid state electronics I cannot begin to imagine, all I know is that it works but only if it's used throughout the entire system. I have tested it time and time again using double blind testing with different sets of ears. to date not one person has said they cannot hear a large improvement. Science has no explanation for this but my ears tell me otherwise.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Toaster on 10 Dec 2013, 06:57 pm
Good points well made. This is part of what I was alluding to earlier; a change that sounds better or worse in a particular system context with the expectations and preferences of particular listeners doesn't necessarily mean that the sound is qualitatively better- it may just be more complimentary to system and tastes. Like audio-heaven I have heard several pieces of equipment sound good and bad- or at least not as good- in different systems and rooms. Also, it isn't just some kind of crude polarisation or battle between 'subjective' and 'objective', there is a whole range of opinion on what can and does sound different, why this might be and what constitutes reasonable evidence. It is the absolute claims that some equipment (or tweek) is universally superior, without any qualification, that causes incredulity in some. On the other hand very 'hard' so-called 'objectivism' that pretty much denies anything except loudspeakers make a difference is also difficult to accept for anyone who listens before they buy or build. I can't see how Julf is that objective- he owns Isobariks!  :wink:
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 10 Dec 2013, 07:12 pm
I can't see how Julf is that objective- he owns Isobariks!  :wink:

:)

I never claim they are the peak of transparency or neutrality, or "better" in any absolute sense - I simply recognize that I like them, sonic warts and all. And when coupled with active filtering and EQ, and driven with high-current, high-damping-factor amps, they are actually somewhat better than their reputation (as long as you accept the tradeoffs of indirect sound).
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: audio-heaven on 10 Dec 2013, 07:36 pm
:)

I never claim they are the peak of transparency or neutrality, or "better" in any absolute sense - I simply recognize that I like them, sonic warts and all. And when coupled with active filtering and EQ, and driven with high-current, high-damping-factor amps, they are actually somewhat better than their reputation (as long as you accept the tradeoffs of indirect sound).
I think you need to do a few tweaks to those Isobariks Julf  :wink: a few Teflon caps, a bit of platinum wire, solid kryptonite binding posts (to keep those pesky Supermen away).......... go on you know you want to  :green:
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 10 Dec 2013, 07:42 pm
I think you need to do a few tweaks to those Isobariks Julf  :wink: a few Teflon caps, a bit of platinum wire, solid kryptonite binding posts (to keep those pesky Supermen away).......... go on you know you want to  :green:

Hmm... yes... And some chrome exhaust pipes and furry dice... :)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: audio-heaven on 10 Dec 2013, 07:46 pm
Hmm... yes... And some chrome exhaust pipes and furry dice... :)
:D that's the spirit, I knew your resolve would crumble eventually. Just paint some flames up the sides, pop a chrome skull on top of em and then you'll have some really serious speakers  8)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: cab on 10 Dec 2013, 09:06 pm
I would always caution anyone against the 'modification' of a piece of electronics unless they know at least as much as the engineer that designed it.

Good advice.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Toaster on 11 Dec 2013, 10:49 pm
I'd be interested to hear them Julf- I've only ever heard them 'back in the day' with contempory Naim stuff. Kind of like a cross between hi-fi and a good PA system. Diffuse stereo but solid and punchy. I'm veering completely OT though, sorry folks.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 12 Dec 2013, 07:05 am
I'd be interested to hear them Julf- I've only ever heard them 'back in the day' with contempory Naim stuff. Kind of like a cross between hi-fi and a good PA system. Diffuse stereo but solid and punchy. I'm veering completely OT though, sorry folks.

Not wanting to continue much further OT either, but Isobariks definitely seem to be in the Marmite category. If you disable the top tweeter and mid, and compensate for the gain loss, they really change character - much more precise stereo, but those lovely room reflections are gone - it's  not a brik anymore! Some people complain about the "bextrene quack" of the B110 mid driver, but it doesn't seem to bother LS3/5A fans... :)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 13 May 2014, 05:18 pm
To revisit the idea of output filter capacitor mods to the NC-400 modules...  I was giving some thought to perhaps trying a previous poster's idea of using stacked PPS film caps, as these are small in size, and avaialble in .22 uF 100V, so a small stack of three would give .66 uF in each position, and keep the loop area very low.
First, I decided to do a little research, since there is not a lot of anecdotal sound quality reports for the PPS film caps.  I went in search of the technical specs (yes actual technical specs for you measurement types...) on various types of film caps.  So here are a few dielectric constants for various caps (for our purposes, lower is better). 

Air: 1, FEP (AKA Teflon): 2.1, Polypropylene (MKP): 2.2, Polyphenyl Sulfide (PPS): 3, and Polyester (PET, stock type): 3.2

So, the potential performance advantage of PPS over the stock PET caps is quite small (of course I would it would also eliminate the steel leads...), and the Polypropylene caps which Rick uses are considerably better.  I really wish Hypex had just had some custom sized polypropylene caps built for these modules... 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 13 May 2014, 06:05 pm
I would love to see a graph mapping dielectric constant to sound quality.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 13 May 2014, 07:12 pm
I really wish Hypex had just had some custom sized polypropylene caps built for these modules...
You should send Bruno an email about this. 


I would love to see a graph mapping dielectric constant to sound quality.

+1
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: gstew on 13 May 2014, 10:00 pm
I would love to see a graph mapping dielectric constant to sound quality.
See Jung & Marsh's 'Picking Capacitors' articles available here:

http://waltjung.org/Classic_Articles.html

In part 1, they list the various capacitors dielectric constants, then in part 2 they discuss the impact of dissipation factor & dielectric absorption on capacitor goodness & sound quality. As I read the articles, lower dielectric constant directly relates to lower dissipation factor and dielectric absorption and to better sound quality.

No direct graph, but pretty strong evidence.

Greg in Mississippi
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 14 May 2014, 05:55 am
As I read the articles, lower dielectric constant directly relates to lower dissipation factor and dielectric absorption and to better sound quality.

Lower dissipation factor and dielectric absorption, yes. The jump from that to audible effects is a leap of faith and speculation, and the articles you link to don't provide any evidence (or even rationale for) that leap of faith.

Quote
No direct graph, but pretty strong evidence.

Not really. Speculation. Not evidence.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 21 May 2014, 04:27 pm
Hmmm: lower dielectric constant sounds better.  Pretty simple really.  Dielectric constant tells the amount of loss of the signal into the dielectric (and subsequent delayed release, the memory effect).  This is the science, not speculation.
Now subjective evaluation of capacitors generally finds that capacitors with lower DA sound better.
So, we have actual technical specifications (measured) which show the DA of various types of caps, and we have a technical explanation of why higher DA would result in signal loss, and we have a correlation between these technical properties (measured) and subjective evaluations.
I am not seeing where there could be any doubt as to why and how different types of capacitors in the signal path can effect sound quality.  Perhaps the absolute level of the effect could be debated (and whether it is audible), but that there would be an effect is not. 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Julf on 21 May 2014, 08:41 pm
Hmmm: lower dielectric constant sounds better.

If you say so.

Quote
Dielectric constant tells the amount of loss of the signal into the dielectric (and subsequent delayed release, the memory effect).  This is the science, not speculation.

Science tells a higher dielectric constant means a higher amount of loss into the dielectric. Any extrapolations from that into audible effects is speculation.

Quote
So, we have actual technical specifications (measured) which show the DA of various types of caps, and we have a technical explanation of why higher DA would result in signal loss

In an attenuating circuit, the higher resistance of a resistor corresponds to higher loss. Does that imply that lower resistance values sound better per se?

Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: *Scotty* on 21 May 2014, 09:27 pm
Julf, you could easily test the hypothesis that one cannot hear the difference between capacitors if you have access to a soldering iron and some film capacitors with differing dielectric construction. who knows what you might learn.
 The simplest test is to insert a series capacitor into the IC that is between your preamp and power amp. You can calculate the size required to give a subsonic rolloff characteristic to 1st. order filter that results when the capacitor is in-line. Theoretically you shouldn't be able to hear that a capacitor is even in the circuit if the pass-band is unaltered. Of course if you can hear the presence of the cap then it is possible that a capacitor with a low dielectric constant might be preferable in this application.
Scotty
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 21 May 2014, 10:48 pm
If you say so.

Science tells a higher dielectric constant means a higher amount of loss into the dielectric. Any extrapolations from that into audible effects is speculation.

In an attenuating circuit, the higher resistance of a resistor corresponds to higher loss. Does that imply that lower resistance values sound better per se?

Actually, yes.  Ask any good analog circuit designer about this.  If it is possible to use less R, it is better, even just from a noise perspective. 
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: gstew on 22 May 2014, 02:21 am
Barrows,

Good to see you posting over here again... and an interesting post on PPS capacitors. You inspired me to go back and look up the Jung and Marsh Picking Capacitor series that I referenced above. Fun to see that seminal article again and remember how it turned the audio world upside-down 32 years ago!

Your dielectric constant comment got me to start a little research on PPS capacitors... I downloaded papers from AVX, Vishay, Kemet, Dearborn Electonics, CDE, and Toray (basically the first few when I googled "PPS film DF") and have done a quick scan of the AVX paper. In their table III, they compare the DA of several capacitor materials and list PPS with a DA of 0.02-0.05, which compares well to the <0.1 values cited for polyprop/polystyrene/teflon capacitors in table III of Picking Capacitors Part II. This suggests that the dialectric constant may not be the only determining factor here.

I also have seen little published information on comparisons of PPS capacitors to polyprops. There is one here:

http://mysite.verizon.net/vze4c5pt/id11.html


Then I have been watching for their use in gear that I respect and found they are used or likely used in the following:

- EUVL's ES9022 DAC module, current version (from DIYAudio)

- Chaki's SD Card Player (as an optional add-on, also from DIYAudio)

- K&K RAKK DAC (based on examination of a number of photos of the board)

- Ayres QB9 (based on examination of a couple of photos of the board)


I agree that I wish Hypex had done some custom polyprops for this position... especially after changing out all three output filter caps in my NC400 to Ric Schultz-styled nuded/outer-film-oriented/stacked Wima polyprops... changing one was a nice upgrade, changing three (after about 3-4 weeks of break-in) was a much stronger improvement and I highly recommend it to anyone wanting to get away from the 'wowee-zowee' sound of the stock modules and gain a good bit of naturalness and increased delicacy without losing the dynamic punch and low-level clarity of the NCore.

I know you have some questions about whether this mod increases the module's perpensity to pick up RF... I can say that the increased clarity, cleanliness, and inter-transient silence I hear after doing the mod suggests it does not.

Julf, you seem to have a habit of taking over threads to push your own ideas and bias in audio systems and components instead of responding to or allowing others to freely respond to the questions asked. For example, earlier in this thread, you write:

"The OP asked for responses to the idea of the capacitor modification. He did not state that evidence-based responses were excluded. If an open and balanced discussion bothers you, you should probably ignore this thread."

What the OP actually asked was:

"Has anyone tried the Ric Shultz WIMA capacitor modification, (replacing a single stock wima cap .68mf with two .33mf polypropylene)"

He clearly DID NOT ask for "responses to the idea of the capacitory modification", but for feedback from those who have done this mod.

I did so, privately.

We are very clear you do not believe in this view of audio or that it has anything to offer in improving sound quality. Also that you believe that anyone who does believe so is deluded and not able to discern the truth. We get that. Please do not introject your views and bias into threads that clearly do not ask for them and are not served by them.

This is all I will say on this.

Greg in Mississippi (flame suit on!)
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: barrows on 22 May 2014, 03:15 am
Luckily I am flame proof as I really care not what others might think about me!
Anyway, from a technical perspective from my research into PPS film caps is that their big advantage is that they can be used as SMD parts with no fears because of the films high melting point.  Therefore they make for a good alternative to ceramic SMD caps, so in some palces are used for power supply decoupling.
I think that most of the examples you mention, they are being used in that way as an alternative to SMD ceramic power supply decoupling caps in analog circuitry.  For sure the RAKK DAC and Ayre QB-9 use polypropylene caps in the output filter circuits...  Ayre is a well know proponent of film decoupling caps right at the transistors in analog circuits, in the QB-9 it makes sense they would use PPS, in their higher end gear they have custom film/foil caps as the final decoupling elements (spendy yes).
My research indicates that there may be no (or very small) advantage to PPS vs PET, I suspect going to polypro is where the significant improvement would be.  At 0.68, a custom part really is in order there.  I suspect polystyrene foils would be even better at these frequencies (I use REL RTE parts for analog stage filtering in DACs and find them to be very good), but of course those would have to be huge-but I really think someone could make a metalized polypro to fit as a custom part.
Oh well... not ready to try the oversized polypros myself, maybe someday.  First I want to try transformers on the Ncore input.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 28 May 2014, 06:29 am
I’m about to receive my upgrade kit for the PS Audio Direct Stream DAC going from PS Audio Mk11. My NC400’s will sing with a more true sound - there certainly was no looking back after hearing the NC400 with the polypropylene stacked caps
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jonbee on 3 Jul 2014, 03:45 pm
I update the stock caps to stacked Wimas (bought from Ric). The improvement is immediately noticeable- more open, clear soundstage, smoother, more natural highs- just a cleaner, more transparent and focused picture, with less hash. Sonically, a no-brainer. I'm VERY pleased. I frankly didn't expect quite such an improvement. The amp now has the all the properties we've come to appreciate, but the improvement in the refinement of the presentation makes it sound a lot closer to real megabuck amps I've heard such as the Darzeel amps.
That said, because of tight spacing on the board, I would not recommend a novice DIYer do this themselves. Fumbling around or using too hot an iron could damage surrounding parts. If I was not confident in my soldering skills, etc., I think shipping the modules to Ric for him to upgrade them would be money well spent if you like the N-cores and want to take them to the next step.
I think it is a shame Hypex doesn't use upgraded parts here, as this mod really shows what these amps are capable of.
Of course I should add this mod will void the warrantee, another reason to put it into experienced hands.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jtwrace on 3 Jul 2014, 03:55 pm
Can you post a picture of the completed mod?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: jonbee on 3 Jul 2014, 04:13 pm
Can you post a picture of the completed mod?
Sorry, I've buttoned it all back up and re-installed it in my cabinet.
My install is nothing special; it looks just like the pics Ric has here:
http://www.audiocircle.com/index.php?topic=110782.0 (http://www.audiocircle.com/index.php?topic=110782.0)
It took about 2.5 hours start to finish. Working in such tight spaces makes me slow down to avoid clumsy or thoughtless mistakes.
I called Ric part way through it because there is a sensor mounted on the board that is also embedded in the aluminum base with grease. This prevented the board from separating from the base as easily as I expected once the screws were removed. Ric advised me to just give it an extra tug, and it did indeed separate properly without damage.
Other than that issue, only the usual problem of solder filling the holes on the board remained to work around, but that is pretty normal stuff when swapping parts.
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: revelinhifi on 15 Jul 2014, 02:50 am
If interested here is a view of mine

and still working after many months. The boards are reasonably resilient to the job of swapping caps. As I experienced this for myself after a few months I learnt that the middle cap is oriented opposite to its neighbouring caps. Therefore I desoldered the modded WIMA and replaced it correctly oriented.

The silver foil is a mastic type sticky tape on the top of the caps sticking and acting as a resonance inhibitor. not pretty but effective for the task.     

(http://www.audiocircle.com/image.php?id=102277)

(http://www.audiocircle.com/image.php?id=102280)

The new Direct Stream DAC from PS Audio is sounding amazing through the modified set of NC400

I could not hear any noise out the speackers with the MK 11 DAC from PS Audio  and Modded NC400's and having the Direct Stream DAC the sound is how can you say - less noise and more correct tones as heard in the natural world "Live" from music and instrument. I have not heard a hifi system that closely resembles the tones to instrument and vocal as I'm hearing now. 

That feeling and desire to upgrade components make mods now has gone and I'm enjoying listening to music  :D
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: EuroDriver on 20 Jul 2014, 05:59 am
What is involved, and how does one get a manufacturer such as Wima to produce a batch of custom caps ?

Besides Wima, who else would one consider ?
Title: Re: NC400 WIMA capacitor modification - polyester to polypropylene
Post by: Ric Schultz on 20 Jul 2014, 08:04 am
I modify the Wima .33uf 100V polyprop caps and sell them as stacked modified and marked pairs (can mail them overseas too) or I can install them in your amps.  You desolder the stock caps and solder in the stacks of replacements.  Please see this thread for more info:  http://www.audiocircle.com/index.php?topic=110782.0 

Wima would not make caps with no epoxy or case on the sides and the steel leads replaced by 6N copper leads and soldered with Wonder Solder Signature and then mark them for outside foil.....nope....these here are tweak thangs.

There might be some better sounding parts but if they are they would be much larger and way more expensive and might pick up noise with long leads.....these modded Wimas have had no problems.....they just give better sound.