Power supply for Super Leach amp

[supernet]

I am going to build a stereo Super Leach amp. It will not operate at full power with my 8 ohm speakers and I just want good supply down to 4 ohm. I am listening at normal sound level and the most important thing for me is good headroom and dynamic response!

Thank you for any idea!

 

[BrianGT]

I am confused at what exactly your question is?

Prof. Leach specifies between +/- 85vdc (270wpc) and +/- 93vdc (300 wpc).

I recently finished making some Superamp boards, and I tested them in Prof. Leach's lab at +/- 50v, as that was the highest setting on the bench power supply, and it worked fine. With this in mind, I would assume as power supply between 50v and 93vdc would work. If you want lower then this, just test it with a dc power supply at the voltage that you want.

I personally see no reason why you would not stay withing the 85 and 93 range, and you could just not run it at full volume.

I have put off my Superamp project for now, as I have not gotten a chassis, transformer or power supply caps. I have my boards finished and they work fine. I am more interested in finishing my pair of Aleph 2 amplifiers, so I have shifted my interest.

Also, I have built a normal Leach amp, and it is 4 ohm stable. I would recommend just running that, if you have not been already.

--
Brian
gte619j@prism.gatech.edu

 

[supernet]

And what you suggest for transformer rating and caps?
I think of using 800VA transformer and bank of 10 caps 4700 microF, each rated at 3.2A. This is just for one channel.
Am I on the right way?

 

[BrianGT]

That should do it. There is really no concept of overkill in building diy amplifiers.

For the transformer, just make sure you have over 600VA per channel, and for the capacitors, that sounds great.

For my Aleph 2 monoblocks, I am using a 1.5kVA transformer and 200,000uF of capacitance for each channel, but this is lot more power hungry project compared to the superamp.

--
Brian
gte619j@prism.gatech.edu

 

[supernet]

Do you use any soft start circuit to limit the current of transformer?

 

[BrianGT]

I am still in the process of working on this project, and have not yet finished the power supply. I have bought some thermistors and was planning on using them as the service manual shows.

I also picked up two fairly large relays, that I am considering using in conjunction with a some large power resistors, as I read in an earlier thread, which I can't seem to find now.

I am pretty sure the thermistors will work fine. I plan on trying the circuit with them first.

The thermistors that I bought were:
Keystone CL-60

Digikey part number:
KC006L-ND

Cost:
$2.58 each

--
Brian
gte619j@prism.gatech.edu

 

[supernet]

Tell me If I use lower voltage for the Super Leach amp, is there a better chance that amp would go into clipping faster?