NC400 WIMA capacitor modification - polyester to polypropylene

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Folsom

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #100 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!

undertow

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Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #101 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.

Folsom

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #102 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.

undertow

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Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #103 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.

Folsom

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #104 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.

undertow

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Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #105 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.

cab

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #106 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.

jtwrace

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #107 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!

a.wayne

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Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #108 on: 26 Oct 2013, 07:08 pm »
Tuff group ......:)

undertow

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Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #109 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.


Occam

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #110 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

undertow

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Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #111 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.


Folsom

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #112 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.

cab

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #113 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.

Folsom

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #114 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:


undertow

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Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #115 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.

cab

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #116 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.....

cab

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #117 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.....

jtwrace

Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #118 on: 26 Oct 2013, 07:54 pm »
Alright guys, whoever wants to have their modded amp measured on a dScope 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:   

undertow

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Re: NC400 WIMA capacitor modification - polyester to polypropylene
« Reply #119 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!