Is the output power tied to the rail voltage

[Shoog]

I am building the basic Zen amp and got hold of a scrap Pioneer professional amp rated at 400watts push pull. There is a really nice transformer in it which has an AC output of 55 0 55v. I really want to use this but only need a low powered amp (my Isophon drivers use about 4watts for average listening). Can I use this transformer without creating a 20watt amp.
I believe that by adjusting the Pot I can increase the feedback and so reduce the ac output. Is using that amount of feedback going to degrade the signal.
What dissapation can I expect on the Mosfets when running at this voltage, and could I use the IRF040. Will the amp run hotter at lower output wattages.

At a pinch I can always buy a new transformer.

Lastly, I dont want to build the Zen lite as I want a user friendly design.

Lots of question, thanks in anticipation.

 

[Nelson Pass]

Probably better to get a different transformer. A 4 watt
Zen is about a 25 volt supply, or about 18 volts AC on
the transformer secondary. A 100 VA transformer will
do a fine job for one channel.

 

[Shoog]

Thanks for that

I was coming round to that thinking.
I will have to keep this beauty for another project (any ideas).
I will be building the revised variable current source, what usable rms would I expect from a 20volt Ac tranformer and what VA rating should I look at.

Great to hear from the man himself on my first posting.