Favorite quad op-amps for synth design?

Tim Daugard daugard at sprintmail.com
Wed Mar 22 16:25:53 CET 2000

>From recent experience:

>>But seriously folks... Its single supply only. Dual supply has a
>>crossover notch that makes it suck for audio.
>[...] piece-of-shit LM324..

* Now I can't see how a crossover notch would disappear only from calling
* +15V "30V" and -15V "GND".

I built a dual log (+ and - log of input) to tame the vocalist's level
variations. (Feed audio through a log amp and . . . instant compression -
and more gain when he pulls away to look at what chord he plays.)

TL074 - nicely behaved at cross over.

LM324 - Distortion highly visable as the negative input crosses from greater
than to less than the plus input reference level. Doesn't mater what the
supply is the cross over distortion has to be from switching some internal
trasistors. - This was more evident in a log amp than a straight amp. I
wanted to use the 324 for natural frequency rolloff but distortion was

Tim Daugard
Lurking and trying to make a living at real estate.

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