[Paul Stamler]

"Arny Krueger" wrote in message
. ..

The scary thing is that Studer used the 301s in a bunch of consoles and
actually managed to make them sound good. I'd never have believed it if
I hadn't heard it for myself.

All things considered that drives another nail in the coffin of the theory
that slew rate always matters.

Not at all; it simply means that you need to take due care. Compensate the
301 for the actual gain being used (if it's unity gain it requires less
compensation, which means higher slew rate) and keep the levels low in
devices operating at low slew rates. If the peak level doesn't exceed
0.5Vpk, and you are conservative about loads, even a 741 will perform fairly
adequately. It won't win prizes, but it'll be all right. Try to get more
voltatge out, however, and you run into slew problems quickly.

My guess, without seeing the schematics, is that Studer kept operating
levels down in their board, compensated 301s for whatever actual gain they
had, and used feedforward for summing amps and, with current-boosting
transistors, outputs. (Feedforward got you something like 10V/us in a 301,
but could only be used in inverting mode.) Ed Gately did something similar
with his mixers in the 1970s.

Peace,
Paul