StephenGiles said:
That must be a Behringer marked chip in there
Actually there are two Beh-tles.
BE501, I guess, is for RMS detection
(either renamed DBX/THAT type chip, or -- less likely -- a CA transistor array. Would that make sense?)
BE267(?), not sure. But remembering Uli's philosophy of making gear as cheap as possible and thus making it available for all us peoples --> What generic 14-pin chip would perform the desired function? Vaguely informed and wild guesses...
- LM339 (a comparator) -- Uli B. likes sticking comparators where you wouldn't expect them (misused as opamps)
- 13600 or the like (transconductance amplifier) -- makes sense there?
Just ideas, no guarantee.
ADDED:
BE267 = LM1894 (Dynamic Noise Reduction System DNR)
http://www.alldatasheet.com/datasheet-pdf/pdf/8688/NSC/LM1894.html