Gainclone <again>

[wotsascott]

I've gone a little crazy building PSU's for gainclones? I build 1, then see another, then do my own design, find another and so on, I'm addicted? Is there a local GA group?
Anyhow, which PSU at 36volts rules the roost? Also, has anyone had hum problems with veroboard, using the overture opamp series? My work mate thinks that the veroboard tracks act like inductors on the signal path? Is he mental? Or????????
Well, I've now got 4 PSU's 1X 36 volt dual of ESP, ! X Brian's at chipamp, 1X Carlos 'snubber and 1X Scott's ridiculous resevoir, light dimming balls up!!!! Which one guy's? Ulp, nope, too late, I've found another 1, save me, help, I need to build?
wotsascott.

[DocLorren]

Sound like the right time to connect one of your PSUs to a Gainclone, put on some good music, have a few beers and relax a little.
Roll some dice a week later to select a different PSU.
Repeat above.
Tell us about the big (...) differences in a month or two.
Dont tell me you only build PSUs and no GCs...

[Nigel Goodwin]

Originally posted by wotsascott

I've gone a little crazy building PSU's for gainclones? I build 1, then see another, then do my own design, find another and so on, I'm addicted? Is there a local GA group?
Anyhow, which PSU at 36volts rules the roost? Also, has anyone had hum problems with veroboard, using the overture opamp series? My work mate thinks that the veroboard tracks act like inductors on the signal path? Is he mental? Or????????

Yes he is! - of course the tracks on veroboard do act as inductors, but so do the tracks on a PCB, and so do the leads on the individual components.

But the inductance of all these is generally far too small to have any effect, until you get to VHF radio frequencies, where you need to take great care over the layout.

Probably a large concern with veroboard is the capacitance between tracks?, but again it's not a problem until you reach VHF frequencies - and many tracks on PCB's will have greater capacitance between them anyway.

Personally, if I'm doing anything on veroboard which might possibly be affected, I remove all unused strips and sections of strips - this also helps if you're using high voltages as well!.

Well, I've now got 4 PSU's 1X 36 volt dual of ESP, ! X Brian's at chipamp, 1X Carlos 'snubber and 1X Scott's ridiculous resevoir, light dimming balls up!!!! Which one guy's? Ulp, nope, too late, I've found another 1, save me, help, I need to build?
wotsascott.

I think you're concentrating FAR too much on PSU's, get a couple of electrolytics, a bridge, a transformer, and get some music listened to!. If you REALLY want to get deeply involved make different ones and listen to them, preferably in blind tests - I suspect you probably won't be able to hear any difference?.

[Nuuk]

Another 'which is the best PSU' thread that is a little irrelvant if we don't know what speakers are involed!

The best PSU (and I have tried most, if not all variations) is a good SMPS followed by the Pedja Rogic discrete regulated supply. But much depends on how efficient the speakers are.

I do agree with the advice to sit down and listen to some music!

[wotsascott]

Well,
Thanks guy's! Got lost but now I'm found?
I put together a LM3886 board and am going to try it out soon. <keep you posted on that>
Ok, is it considered best to us a dual supply psu, one for each channel, possibly 2 transformers, or can I use a single supply and run both channels from said single?
Also, does it matter if 1 transformer is 250va and the other is 300va, although both have twin secondaries of 25v? <so I get around 34-36v>
I've spent so long secondary listening to music while I work on the computer I've lost site of the reason I've started this in the first place, so thanks you guy's it is much appreciated to be reminded it's all about the music!!!! <and beer>
Cheers,

[Nuuk]

If this is for listening for music while you at the computer, I would use any one of those transformers, a couple of rectifier bridges and leave it at that.

[phn]

Stereophile has a few interesting things to say about the Gaincard and single/dual PSU. Here's the Review.

[Nuuk]

Stereophile has a few interesting things to say about the Gaincard and single/dual PSU. Here's the Review.

From that article:

In some areas—the lack of intermodulation distortion, the superb squarewave performance, the wide bandwidth—the 4706 Gaincard offered excellent measured performance. In fact, almost all the measured problems I encountered can be laid at the feet of the Humpty power supply. Given the very high sensitivity of Robert Deutsch's Avantgarde speakers and the fact that they use powered woofers, it's possible that these problems didn't impinge on his auditioning. It should also be noted that the negative effects of the Humpty power supply's current-delivery problems would be eliminated were each channel of the Gaincard driven by its own supply. However, this would add $1800 to the amplifier's cost, which makes the package seem expensive for just 25Wpc.—John Atkinson

or (in the system mentioned above) for 22UKP (42 USD) you could use an SMPS for each channel, probably get better sound, and have 1758 USD to spend on something else!

[DocLorren]

Fully agree with Nuuk,

Try whatever PSU you got on hand (and you got quite a few already), be it single or dual or switched but first listen and appreciate what can already be achieved by the simplest set-up. Using two transformers with identical sec voltage but (slightly) different VA rating is not going to be noticed. Especially not since around 200 VA is already plenty for normal GC use.

[!]

Keep in mind that like tube amps, use of a SMPS will always introduce distortions if it sounds different at all from a textbook linear regulator with a fair amount of capacitance after it. That is why SMPS sounds different which some describe as better. It may indeed sound better, to some people.

SMPS cannot track as close as a regular linear, they always have dirtier power in addition to HF components. Apples/apples, filters can be added to SMPS output but then if one put filters on the linear too, the linear is technically still superior as an analog audio supply.

As both are beefed up to make an ideal comparision, then the differences between them disappear and the SMPS becomes as expensive, as large (once the additional filters are tacked on), but still lighter weight due to less bulky transformer.

That's not to knock SMPS though, but you have to know if that is the sound you want by trying it and contrasting it.