again and again, which amplifier?

[SDF]

Hello DIY'ers, I open this thread hoping somebody will be able to give me some advice to choose, one more time, which amplifier built.

I made a Proac 2.5 clones and research, now, a low power amplifier (but very good of course) about 25W.

I don't know which choose between an aleph5 schematic with +-25V supply, a Penultimate Zen amplifier . The third amplifier is the Aleph X but I believe it needs balance line...

So my preamp have, only, unbalance output line so I just want to know which between this two or three amplifier wil be the more electricaly appropriate for my speakers?

More I have a +-25V voltage supply made with 4*10mF (for each channel), can I hope to obtain good results or not?

Thank for your answers

[Peter Daniel]

If your PS delivers +/- 25V after filtering, it's too low for Aleph5 but good enough for Aleph 3, which is about 30W. It's way too much for low power version of Aleph X. 40,000uF for ea. channel should be sufficient.

You might also check this: http://www.diyaudio.com/forums/showt...4122#post84122

[SDF]

First thanks for your answer.
It seems the alephx has a greater sound with symetrical input and I don't have.
I think I will made the regulated supply of son of Zen rated at +-20V. I will use a 2*18Vac transformer and 40 000µF/40V (by chanel, I precise) .

So, anyboby know if made that with the aleph3 amplifier seems to be, or not, a possible project?

And if I can also hoped to have a great sound, near to a 'normal' aleph3 with, of course, less power?

ONe last question to finish, in the alep3 and 30 owner's manual, the 3 has 2.12A bias current and the 30 has 1.6A, what is the best bias?

[Peter Daniel]

Higher bias is better, so if your heat sinks allow it, go for higher bias. Aleph 3 or 30 will work with lower supply voltage with no problem. BTW, Aleph X works equally well with single ended input.

[SDF]

Hi Mr Daniel, thank for your advice, if I use single endeed input it means the -input should be plug to the ground, isn't it?

I know you have made some amplifiers, and I can you say me which is your favorite between an Aleph3 and an alephx, considering an unbalanced input?

More if you would sent to me the schematic of the last version of the alephx, I will be very happy...

I see it on some thread but with the high number there are, I don't really know which is the 'good' (and last) version.

[Peter Daniel]

It seems like Aleph X is everybody's favourite now. I've seen people dropping their regular Alephs projects and deciding on an X project. I had my reservations about single ended driving the inputs on Aleph X, but Nelson Pass responded that it won't be a problem.

Large number of boards is being ordered for that project, so support would be great, you shouldn't worry about any difficulties. Here's the schematic:

http://www.diyaudio.com/forums/attac...=&postid=43959

[SDF]

Thank again.

Sorry for my unceasing questions but on the schematic, the PS is +-12Vdc so how power can I hope ta have with the minus input plug to the ground?

[Nelson Pass]

The difference in sound between balanced and single
ended input on an Aleph X is very minimal as long as
you terminate the unused input in something resembling
the source impedance of the circuit driving the other input.

For less than 100 ohm sources, a direct short to ground on
the unused input is fine.

[Peter Daniel]

If the positive input is coupled through 0.022u (for high pass filter), should the negative be connected to the ground through the same capacitor value for single ended operation?

[Fred Dieckmann]

And yet only 2 or 3 besides the Passlabs folks have heard one,
what ever that particular version was, which is not quite clear........... You people are giving me a bellyache from laughing so hard. Maybe a few people should build it, listen to it, and actually document what exactly what they built and what they compared it to. You guys are confusing "actually hearing" with "hearing about" again.

Amused to death,
Fred