Some questions...

[Vincent Volta]

Hi all!
I tried this circuit in a kind of hybrid distortion, MXR+ style, and worked great! I changed the clipping diodes for a pair of LEDs and messed a little bit with the gain too. I found that it needed the diodes on the feedback loop too, like the TS9, or the sound would be destroyed. Cool sounds... Im a lot into amp building so my first question is, do you think this would be fine to try on a preamp circuit ( there would be several stages of course- 3 or 4) on BOTH the clean and lead channels? My last amp build has a discrete clean channel and is waiting for its lead channel, which will be the aforementioned circuit. But the voltage supply, as on many amps, is 12v DC. Will this work as well on that voltage or should it be lowered? Last but not least, has anyone tried a Rat circuit with the discrete opamp? Thanx a lot for your patience and help!

[Joe]

12v should work, but may require some tweaking of the 4.7k resistor to get the output at 1/2 supply voltage. Instead of multiple stages, try doing something like the first two stages of a Shredmaster with the discrete opamps. (2nd stage requires a 1uf cap across the lower 10k resistor as explained on the page.) My results with that circuit were very good.

I never had to use diodes in both feedback and shunt positions, just one or the other. But I never used LEDs either. In non-inverting mode it definately needs a diode clamp somewhere or the results are bad.