[Malcolm Fear]

Let's put all improvements to AKSA 55 here.
Using the Linn philosophy, first there was Nirvana, then Valhalla.

[cmscott6]

I just finished changing all of the electrolytic caps on my 55N to Black Gate Standard (except C3, which was earlier changed to BG FK).  Even though BG's are supposedly slow to break in, I can tell a difference immediately!  Cymbals and upper register piano chords are much more detailed and life-like.  Almost as if you are hearing all the harmonics connected with each note.  Same with the bass  - acoustic bass notes are rich and full of harmonics - you can really hear that it's a wooden instrument resonating.  It also seems to just improve on the already great imagery of the 55n/gk-1 combination: each instrument is entirely distinct.
Sorry, I don't have the audiophile lingo down, but I would highly recommend this tweak.  Referenceaudiomods had the BG caps for a little cheaper than usual, too.

[AKSA]

Hi Chris,

I'm listening hard, man.......

Now, I guess this makes a difference!

How much are these critters and where do I get 'em?  

Are they physically larger, Chris?

Also, IIRC the usuals are just 50V, so they can't be used for the 100W AKSA.  You have to go to the 100W AKSA, and they are VERY expensive, too expensive for the kitset as it stands.  

Cheers,

Hugh

[Occam]

1. Iff'n you doubt that powercords make a difference, buy the Volex 17604(5), 2 & 3 meters, 14ga, shielded powercords. At less than $1/ft, when ordered in quantites of 2 or more from -

http://www.carlton-bates.com/cb/invsrch/invframe.asp?srchfield=pmmpn&vendor=ALL&codevend=volex&sval=1760&submit1=Go

you really aren't at risk for much, even if I'm blowing smoke up your arse...  Buy eneough to replace all your component's OEM cords. Don't assume any equivalent cord will do the same; the equivalent from Unicable truly sucks. The Volex is the ultimate 'cheaper, next best' pc. There are certainly better (IMO subjectively) cords out there, but  'audiophile approved' cords tend to be rather expensive in comparison. You should be comparing these boutique products to the Volexs, not whatever vou had lying around to judge whether the incremental cost justifies incremental benefits. Can't make any suggestions for non US/Canada/Mexico builders.

2. Use a dpdt (on-off-on) power switch. This will allow you to reverse the Line and Neutral wires, while still preserving the fuse's needed function, and is far prefferable (and safer!) to using a cheater plug to minimize hum and/or noise. Anyone who has used an aftermarket 'table wart'  powersupply for their D/IO  (or the Parasound 3500amplifier) will testify to desirability of this feature.  The only vendor I know of that does this on commercial products is Bruce More Audio Designs. Lacking access to metal punches, I use a dpdt 20Amp, 1 1/2HP(indicated the ability to handle the surges associated with inductive loads) rated , toggle switch. These are substantially more expensive than a rocker switch.

3. Build a power/surge filter into your amp (or into your outlets, or a seperate box). I've never found, or know of anyone who has found Corcom, etc... industrial filters to be anything other that a negative on poweramps. And filters with inductors can be problematic also. What I'm suggesting is a simple X2 rated cap accross the line and Y2 rated caps from line and neutral to the ground (leaving out L1, L2 and C4 on Jon Risch's site).  Be careful as to the amount of capacitance so as to not trip your GFI circut, if you have one. Add MOVs for surge protection to suit. This shunts noise coming into and out of your amp. Please see Jon Risch's site for more detail, and remember that line voltages will kill! If you're unsure, don't do it! -

http://www.geocities.com/jonrisch/surge.htm



PS - As these comments pertain to both the 55 and 100 amps Nirvana or Standard, as would most all suggestions (except some voltage ratings on some electrolytic), wouldn't it make sense to combine their Valhalla threads?

[Regis B]

Hi Chris,

I'm listening hard, man.......

Now, I guess this makes a difference!

How much are these critters and where do I get 'em?  

Are they physically larger, Chris?

Also, IIRC the usuals are just 50V, so they can't be used for the 100W AKSA.  You have to go to the 100W AKSA, and they are VERY expensive, too expensive for the kitset as it stands.  

Cheers,

Hugh

Well the 100Watt is not that expensive $14,40 for theFK and $4,65 for the standat BlackGate. I had more gain over stock from using Panasonic FC Cap and just replacing the Suckout Cap with RELCAP - TFT capacitor.
I have also added 10000 elna cerafine main cap bypassed with Relcap RT Polystyrenecap witch provided a nice improvement.

PS don't ask me howthe gk-1 sound I'm popping $6 pill for a ear infection.
everiting sound and fell distorded .

Au revoir Regis.

[cmscott6]

I should be more specific that I replaced all of the main board caps with Black Gates: 100uf, 50V standard for C4, C10 and C12 ($2.95 from referenceaudiomods.com); C2 and C7 (10uF, 100V standard) from a generous friend; and C3 100uF, 50V FK from Michael Percy ($10.95).  The 100uF caps just barely fit with a little scrunching; the 10uF fit fairly easily.  You do have to drill the holes in the PCB slightly bigger to fit the thicker leads of the BG.  
Needless to say, I did not replace the PS caps with Black Gates - one look at the price list was all I needed     Just for kicks I am thinking of trying Nichicon FG caps in the PS.  I'm in no hurry now, tho - everything sounds pretty good (for now anyway)

[mb]

I'm all for exploring the limits to the improvements available based on Hugh's designs, but I'd like to just bring up to comments (not quite concerns, but edging that way...):

1) I'm not sure that will be ONE Valhalla for all of us. Even based on Nirvana, I believe many of us apply tweaks, use alternate components, and otherwise do many things to get our AKSAs sounding the way we each like.

2) I've made it a conscious point not to pour too much money into truly exotic parts for my AKSA. Hugh makes a remarkably musical range of products based on non-exotic parts, and that's a major attraction for me. I have substituted a couple of parts, but that's in part because I believe certain technology sounds better in my DIY projects (eg. schottky v FRED, polypropylene film v metallised polyester).

I'm reasonably confident that BGs or Gold Tunes, and TRT Dynamicaps can bring my AKSA up a notch, but luckily the thought of the cost + effort is holding me back .

3) Finally, if there is to be Valhalla, I hope that will be Hugh's offering to us, based on his choice of parts and his listening preferences. I'd rather not have this group hijack the Valhalla from him.

That said, I'm looking forward to reading everyone's favourite tweaks / mods. Mine is 1.0uF Auricaps at the input, replacing the Rifas. I know Hugh doesn't particularly like the Auricap as input dc blocker, but we usually agree on the 90% of his component choices.

[AKSA]

Thank you Mal, Mervin,

So - Valhalla it is!  I'm confident the Thor/Odin loving Vikings will enjoy this nomenclature!  

A few words about this sudden turn in the forum.

1.  I'm happy to research and develop a Valhalla upgrade.  I think it would be a good seller, but it should only be an option, never at the entry level.

2.  I need to very carefully account for the business realities.  Holding an inventory of Black Gates will be expensive, and the initial purchase will be a risk, since only a small proportion will buy this upgrade.  Until I rebuild capital holdings depleted after the R&D of the GK-1 (now on sale, lots of stock!!    ), I would be willfully indulgent to commit Aspen to more stock, particularly knowing that only a propportion of kitset purchases would require these valuable components.

3.  It is evident that there are a few people who take the 'cost-no-object' attitude to componentry.  However, to be fair, these guys (and Mal is one and I applaud him!) will only take this approach when they have satisfied themselves that the basic amp design can accommodate high quality components, and reward the builder with even better sound.  A significant factor in this is that five dollars spent by the builder 'tweaking' on spec is subjectively worth about two dollars spent on upgrade componentry at the time the kitset is purchased.  The concept of 'intellectual ownership' kicks in a different buying psychology altogether.  I believe a Valhalla approach would lock out first timers, who buy on two things - perceived price/performance, and the promise of tech support at little or no charge.

4.   I voice all the Aspen products how I 'see' it, with some regard for the impressions of others, whom I invite along to listen with me.  I do this with a gimlet eye on costs, and I work very hard to achieve the sound I want with careful component selection and appropriate dimensioning.  If the AKSA kits go upmarket, they should do so via optional upgrades so as not to lock out the all-important cost-conscious buyer.

5.  To offer Black Gates in the amps I would need to spend around $US600 just to hold minimum inventory.  Holding stock is expensive and risky, and of course I'd have to get it all from the States or Japan.  

6.  Lastly, it would seem the product can deliver even more sonic performance.  In truth, we have a product which is already very good;  even more performance on the back of component upgrades would be seriously competitive with some very high end amplifiers.  Whither Aspen then?  What will happen to the DIY direction of the company?  

Cheers,

Hugh

[Jens]

Hi Hugh,

Since I seem to have set this ball rolling (close followed by Mal and others) I feel I should add a few comments.

So - Valhalla it is!  I'm confident the Thor/Odin loving Vikings will enjoy this nomenclature!  

This Viking finds it somewhat funny that the religion of his forbears should actually end up having something to do with audiophile nomenclature!

A few words about this sudden turn in the forum.

1. I'm happy to research and develop a Valhalla upgrade.  I think it would be a good seller, but it should only be an option, never at the entry level.

2. I need to very carefully account for the business realities.  Holding an inventory of Black Gates will be expensive, and the initial purchase will be a risk, since only a small proportion will buy this upgrade. Until I rebuild capital holdings depleted after the R&D of the GK-1 (now on sale, lots of stock!! ), I would be willfully indulgent to commit Aspen to more stock, particularly knowing that only a propportion of kitset purchases would require these valuable components.

1. I totally agree. One of the charms of the Aspen products is their very good price/quality ratio - no point in destroying that image.

2. The BGs may not be the only upgrade that is more expensive than is usually seen with Aspen products. However, BGs and most other upgrade components are readily available from various mail order outlets specialising in this sort of thing, so it would not be necessary for you to hold a stock of these items, unless you wish to.

When I suggested collecting all known upgrades in one thread, it was just intended to make things easier for all of us Aksaphiles if and when we should want to upgrade our beloved AKSAs even further. I also thought that ultimately it might serve as a help and inspiration for you, if you wanted to put out even better products at some point.

6. Lastly, it would seem the product can deliver even more sonic performance. In truth, we have a product which is already very good; even more performance on the back of component upgrades would be seriously competitive with some very high end amplifiers. Whither Aspen then? What will happen to the DIY direction of the company?  

6. No doubt about it - the Aspen products have great potential and in many respects already compete with some of the very expensive stuff. And with further enhancements they could very well end up at the forefront. The question is, I think - which way do you want to go?

Cheers,  

Jens

[bluesky]

Fellow Elder Aksaphiles

I am going go show my ignorance here but....... if you don't ask you'll never know.

Could someone explain the various types of Black Gates and just why they are so good?  I see people refer to standard, FK etc.  What do these mean and which is the best for our purposes.    

Thanks Ian

[mb]

2.  I need to very carefully account for the business realities.  Holding an inventory of Black Gates will be expensive, and the initial purchase will be a risk...

I agree, and more. Many who are keen on a no-holds-barred version probably already have some experience with BGs, Cerafines, Gold Tunes, etc, and have also tasted Auricaps, Hovlands, Jensens, etc. They know where to get the BGs at the best prices for their market.

At a Valhalla level, I'd also be looking into the 'best' attenuator (41-step TKD?), Dale/Vishay or other high-end resistors, etc, etc. Aspen will never be able to compete with our local / regional / US-based stockers of these exotica.

Otoh: if Hugh does have a Reference top-top end version, call it Valhalla or "HD Signature" or whatever, I would be open to paying to access the proprietary information for this model, then choose to selectively this top-end version. One possible advantage of have a Reference model is the bragging value. On a practical front, the Reference will potentially lead to trickle-down improvements on standard and Nirvana versions.

[EchiDna]

at the risk of going further off topic...
IMHO of course!
I agree with everything MB said and go even further to suggest the "Valhalla model" should be a completed, built and designed by Hugh, packaged amplifier ONLY.

What we as DIY constructors choose to do with our tweaks etc should be our experimentation, not Hugh's new nomenclature...

I agree with sharing tweaks, ideas, cost no option additions etc... as a reference database of a sort, just not naming a new range on behalf of Hugh. I think that is unfair to him and his future business options on the products.

Unfortunately for Hugh, he is not quite in the PASS labs business size yet so he doesn't have a range of off the shelf amps and a secondary DIY  business, the DIY side IS the business...

Ok sorry, I went way off topic...  

[Raj]

Hi,

With regards to caps especially the standard polarised black gates as well as the FK/K variety, these are said to be outperformed in tests against regular non polar electros's, the types you often find in loudspeaker crossovers, although the standard Bg's are not that expensive, the non polar electro's are cheaper still and introduce less distortion.

Distortion may not be the key to great sound but perhaps in caps it helps......

Given the price of non polar electro's it shouldn't hurt for some experimentation in this department. The reason these havn't quite caught the buzz in the tweaker league is cause the price is so cheap that many don't have faith in their ability.

Thanks
Raja

[PSP]

I had an experience last night that suggests that you can get some nice improvements in AKSAs without necessarily replacing all your electrolytics with Black Gates.  Personally, I ordered my Black Gates over a week ago, but I tell this story for the benefit of those who would rather find a lower cost option.

When I built my first 55w AKSA (two years ago?), without even thinking about it, I replaced all of the stock electrolytic caps in the kit with Panasonic FC caps (I think Harvardian, Dale Herman, suggested this initially).  Later, when I applied the Nirvana upgrade, I used the caps Hugh supplied.  So, I then had a 55w AKSA in which all of the electrolytic caps are Panasonic FC, except for C2 and C7 where I used the Nirvana upgrade parts Hugh supplied.  I'll call this amp AKSA #1.

I liked that amp a lot, so I bought a second (and a third, but that's a different story) 55w AKSA.  This amp was put together with stock parts, then upgraded with Nirvana parts.  I'll call this amp AKSA #2.

For the last year, AKSA #2 has been in my bedroom system (Luxman Z111 CDP, Foreplay preamp, GR Research Paradox-1 speakers).  I've been very happy with the way this rig sounds.  Last night, I replaced AKSA #2 (stock caps except the Nirvana parts) with AKSA #1 (Panasonic FC caps except for the Nirvana parts) and immediately noticed a significant improvement in detail, clarity, and maybe the bass as well (the Paradox 1s are pretty good to 55 Hz).  Now the AKSAs have always been excellent in these areas, so to say that there was a clear improvement is saying quite a lot, I think.

It is important to note that I did not have "amp with different caps" on my mind when I made the switch... I was simply shuffling the amps around to facilitate putting the Black Gates into AKSA #1 when they arrive... in fact I made the switch, then left the bedroom for a couple of hours to do some work, and then went to bed, and when I turned on the music found myself very pleasantly surprised by how good this amp sounded.

End of story.... except that my third 55w AKSA (also Nirvana) is a twin of AKSA #1 (has Panasonic FC caps) so I am all set up to make an excellent comparisson of Black Gate vs. Panasonic, vs. stock electrolytic caps... that will probably take a few weeks or a month, but it should be very interesting, yes?  By the way, all my AKSAs have been carefully biased to 55mv and have DC offsets (measuring between speaker hot and ground with RCA inputs shorted) under +/-10mv.

Peter

[Malcolm Fear]

Hi PSP
I look forward to your comments on the Black Gates.
Living in Australia has some disadvantages. It will take a while for my Black Gates to arrive.
I am also going to try a Riken Ohm carbon film resistor at R9 (82K).
I tried on in the GK-1 (playing around with a shunt attenuator), and it sounds better.

[U4EA]

PSP,

No disrespect intended.  I don't know how the heck you keep track of all your amps/caps!!!

[PSP]

Good question... no disrespect heard, seen, or felt.  First of all, the caps are all soldered into the amps, so they are easy to find, and the amps themselves are too heavy for the cat to carry away...  

OK... the real answer:  One amp is in the bedroom, one is in the main system, and the third was intended to be used in a biamp setup in the main system.  Since I just bought a pair of Danny Richie's (GR Research) last remaining Paradox-3 floorstanders (at a really excellent price, BTW) it will at least a year or two (maybe never) before I biamp that speaker (I want to listen for a long time before I try to "improve" on Danny's work... I have the same respect for him that I have for Hugh... these guys are profound masters IMHO).

So, since AKSA #3 won't be used for biamping in the near future, I will use it for A-B comparisons as I tweak... and I will also likely use it to drive the rears in my "pretty basic but getting better" HT setup.

Keeping track of things... for the most part I make changes very slowly, listening as I go.  

Peter

[Vinnie R.]

For my aksa 55, I built separate L and R power supply boards that each use a 6,800uF 63V Panasonic TSHA cap per rail (separate grounds, so this is true dual mono, as nothing is shared).  I also used international recifier MUR1020CT 10amp, 200V diodes (TO-220 package).  The TSHA caps are very good, very clean, and not nearly as expensive as BG's, and I find them better than Nippon Chemicon.

There was much improvement over the original Nippon Chemicon KHM 4,800uF 63V caps.  The bass was tightened a fair amount (I love tight and punchy bass), mids stayed the same, highs became a little more focused and present, but still a pleasure to listen to.  I was very happy.  It's just a matter of taste, but I think all would find the bass improvements awesome.

http://photos.yahoo.com/vinnie822

I need to update these pics somewhat and finish the front panel, but take a look at the power supply boards and the two relay boards that use Potter and Brumsfield 5V coil, 250Vac, 30A relays.  I added protection diodes for the coil and also the cap and series resistor across the mains as Hugh suggests.  

The  volume controller is a passive APOX unit, which is a stepped attenuator that I found sounded even better than my DACT CT2, and it provides the 5V for the relays when I turn on the unit (remote controlled or manual).

-Vinnie

[PSP]

Hi Vinnie (and other folks),
A while back, there was a thread or two on dual mono power supplies for the AKSAs.  Now that a couple of months has gone by, I'm wondering how happy people are with their dual-mono setups, and if there are any additional "cool recipes" to share (in addition to yours).

Thanks,
Peter

[Malcolm Fear]

Hi Vinnie R
I have a DACT CT-2 stepped attenuator.
I turned it into a shunt attenuator using a Riken Ohm resistor. Made a considerable difference.
Nice schematic at Goldpoint
http://www.goldpt.com/schm_shunt.html