I built a modded version using ideas from Gus, Gary and Alf, etc. and really like the smooth yet ample distortion. I have tried the usual suspects for the dual op amp 4558, 4559, 353, 412, 072, and 052 and so far the 052 is my favorite. The 4558 has a "swirl" to the distortion that makes it appealing, but the TL052 has more "gain" and distortion.
I used a 1 meg resistor in both feedback loops, a single diode in the first for assymetry, and 2 in the second.
Yesterday I optained samples of an OP275 and it sounds nice for a few seconds then goes quiet. If I remove it, it starts up again when plugged back in. Both do the same thing, but none of the others do.
Also, if I use just 1 diode in the 2nd stage it cuts out until the signal dies down and then sounds OK.
I'm trying to figure out if something is wrong with it, or if the op-amp is just being overloaded and self protecting Any ideas?
HMMMMMMMMMM. Well I disconnected the diode in the first loop, didn't seem to be doing much, and now the OP275 is smoking, figuratively. Sounds nice. More Electronic Mysteries.
Interesting work, WGTP. What are the sound differences with the jfet/mosfet clippers? Is it a different shade of dirt?
Yes, the J201 and 2N7000 sort of have the characteristics generally attributed them in other circuits. I kind of like the Jfet, but the Mosfet is brighter. Just tried a SI/GE in series with an Led for the other direction. Really is a Mockman now with diode variations. Thanks for the design.
I'm trying different op amps and will report final results. 8)
I'll be waiting.