High-End Regulated Buffered Inverted GC

[carlosfm]

We are reporting VERY good results with the LM338 and LT1083.
You can test other regs, it's up to you, if you don't believe the hype...
I'd rather spend 4€ on each reg than have inferior parts for free, the PSU takes some work to do, you know?

[chrish]

Yes, I know what you are saying
Just that I finally got my act together and mail ordered all the parts required for my 4 channel gainclone and active crossover when I read this thread with regulated power supply

Another question, I am running a pair of Brian's premium kits at the moment with 1000uF Black Gates, I don't feel like spending the money required to buy 8 4700uF Black Gates for the regulated supply (or 16 for 4 channel!). Is the circuit critical of the quality of the capacitors between the transformer and the regulator? I would like to buy low price here if it makes little difference and get high quality for the rest.

Thanks,

Chris

[carlosfm]

Chris, good news: it's not critical the caps before the regulator.
You can use normal caps there (well... except those ultra-cheap light green cheapies ) and bypass with 0.1~0.47uf polyester caps.
It's what I've done.
The influence of the quality of the caps before the reg are not nearly as big as on the unregulated PSU/GC.

[jackinnj]

if you are going to regulate a GC -- take a look at this baby from Power-One
http://cgi.ebay.com/ws/eBayISAPI.dll...821319758&rd=1

PWER is a major supplier of power supplies to Cisco, Lucent, Nortel, etc. Mostly they make switchers.

[jackinnj]

Originally posted by Microchip_Usa

Any chip based amp is a JOKE.

It's not a joke, it's actually quite a nice compromise. These chip amplifiers do sound good, and the measurements stand up well to criticism.

With respect to regulation -- the LM3875 and LM3886 have PSRR of 120dB -- there is no need to regulate the power supply -- what Carlos should do if he believes so firmly that regulation is necessary is to build the DC measurement test jig shown in illustration 1 of the LM3875 datasheet -- then measure the PSRR with and without regulation.

One of the reasons that Nelson regulated one of his Audio Amateur designs (must have been 1991 or 1993) was the poor PSRR.

[Peter Daniel]

Originally posted by Microchip_Usa
For a good example once again take the Pass labs Zen Amp simple, easy to make. It’s high end and it works fine

Originally posted by Microchip_Usa

What is simpler then Zen my friend?

I've built at least 5 Zen amps. To me they are more complicated designs that chip amps.

Also, I prefer the sound of chip amp to the sound of Zen. I sold all my Zen amps.

I have also built Aleph X amp and I still prefer to use chip amp as it sounds better to me.

The truth is, I didn't tweaked my Aleph X as much as I tweaked the chip amp and Aleph hasn't got red solder mask

I believe that both of those amps, (Aleph and chip amp), when properly set up and tweaked, may deliver very satisfying listening experience. I can't say which one is better, as it depends on many other factors.

I hope that SOZ might be better than chip amp. I will be building one soon

[BrianGT]

Originally posted by Peter Daniel
I've built at least 5 Zen amps. To me they are more complicated designs that chip amps.

Also, I prefer the sound of chip amp to the sound of Zen. I sold all my Zen amps.

I have also built Aleph X amp and I still prefer to use chip amp as it sounds better to me.

The truth is, I didn't tweaked my Aleph X as much as I tweaked the chip amp and Aleph hasn't got red solder mask

I believe that both of those amps, (Aleph and chip amp), when properly set up and tweaked, may deliver very satisfying listening experience. I can't say which one is better, as it depends on many other factors.

I hope that SOZ might be better than chip amp. I will be building one soon

What about trying a highly tweaked X-SOZ?

--
Brian

[Peter Daniel]

I might try it too, but first i would be tempted with a regular SOZ.
There are many stories of improved circuits, but usually the simplest ones do sound the best

[carlosfm]

Originally posted by jackinnj

With respect to regulation -- the LM3875 and LM3886 have PSRR of 120dB -- there is no need to regulate the power supply -- what Carlos should do if he believes so firmly that regulation is necessary is to build the DC measurement test jig shown in illustration 1 of the LM3875 datasheet -- then measure the PSRR with and without regulation.

No measurements, just my ears.
If you read this thread carefully and the other one (link on the first post), you'll understand why.
It's not a question of PSRR at all.
It's a question of stable voltage, and also because these chips sound good with only 1000 to 1500uf capacitance on the (unregulated) PSU.
I think that you understand that this is a huge limitation for a 50 watt amp.
If you increase capacitance you muck up the sound, if you regulate...
I'm the one that always tell people to don't banalize the word high-end.
I only use it when I LISTEN to something special.
This is one of those things.

[Peter Daniel]

Originally posted by Microchip_Usa

What is the Aleph X amp based on? Have not heard of this amp yet?

It seems like it's based on two regular Alephs It's the latest commercial offering from PassLabs.