Rails do not have to be balanced at all, even wild differences like +15 and -25 or +25 and -15 should make no difference to the operation apart from asymmetric clipping as the output hits one rail before another.
OK
so I would need to see the correct version to make an informed choice over what transformers might be suitable. As you have a PSU (and assuming it generates a split supply) then try it and see what happens.
OK
so I would need to see the correct version to make an informed choice over what transformers might be suitable. As you have a PSU (and assuming it generates a split supply) then try it and see what happens.