Here's a very cool Rat variant now out of production. Fairly straight forward Rat with a variation of the Ruetz Mod, LEDs for clipping and a switch to toggle a feedback loop. On the original this is a toggle (SPST), but would be fun to put on a momentary footswitch. Couldn't confirm the IC in the original, as the markings were painted over. Might be easy to assume the IC is an LM308 or OP07 since it's based on the Rat, but it's missing the compensator cap (30pF cap across pins 1-8 in a normal Rat) so I'm guessing a TL071/LM741, but an OP07 would work too. Fits nicely in a 1590B or 125B. Schematic here
Thanks for verifying!
ReplyDeleteVery cool. Tons of gain. I recommend socketing the LEDs so you can play around with different combinations, or different types of diodes. The green/red combo seems to work best for the Havoc switch. Standard issue red/red LEDs sound terrible. But, a pair of red LEDs I got from pedalhacker sound fantastic. A pair of GY102s gives it a completely different character. And -- "havoc" on a momentary switch makes it much more useful. Definitely going to box this one up.
ReplyDeleteWhat op amp did you use?
DeleteI used a TL071. And, after some experimentation, 3mm LEDs seem to get closest to what I can hear from youtube demos. Without an original in hand, it's hard to tell.
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