MOTM

a) Sorry, I meant to say "1975-1995".

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'.

c) Look at the 'mythical' Ibenex Tube Screamer pedal for folks who even
like *certain date codes* of 4558s :)

Paul S.