MOTM

>b) the 4558 and also the low noise (but power sucking 5532) have a very
>distinctive 'peaky in the midrange' sound. They don't have a "big bottom
>end" and the overall sound is sort of 'grainy'.

Isn't the 4558 one of the op-amps that doesn't phase reverse and/or
latch-up? That should make a difference when you start punishing it.

-- 

Terry Bowman, KA4HJH
"The Mac Doctor"