Powering amplifier from two coil transformer

[6c4c]

Hello!
I have U core transformer with two coils. Each coil has a two secondary sections (different), and I want to power each power amp channel from a separate secondary winding. What's better, power each channel from sections of one coil or use sections from both? Channels work in cl.A and needs unipolar supply.
Thanks!

 

[Mooly]

Powering from separate windings could in theory allow for better isolation and less problems with ground loops.

Very hard to say without knowing all the details. You make it sound as though the two secondaries are different anyway. It might be easier if you draw the proposed wiring scheme and maybe pictures of the transformer

 

[Elvee]

On this kind of transformer, all windings are normally spread 0.5/0.5 between the legs, both primary and secondary, and they are all meant to be associated in series or parallel.

Doing otherwise will increase the leakage inductance and lead to poor regulation.
Sometimes, that is the design goal: like in ballast/Xformer combo's for gas discharge lamps.

I don't know whether it is one of your design goals for this supply?

 

[6c4c]

I like more the version on the right

An externally hosted image should be here but it was not working when we last tested it.

 

[Mooly]

My instincts say use the one on the left to avoid modulating one supply from variations in the other.

Beyond that I wouldn't like to say without doing tests to see what really happens with random unequal loads on each.