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|previous: Humbucker I have a 1991 re-issue RAT and I've... -- 1094220966||View Thread|
|9/3/2004 1:00 PM|
|JS||Re: Need info on RAT op-amp.|
LM 308N is the correct op-amp.
I´ve got an unit from the early eighties with the same op-amp.
Make the connection of the 2,2(4,7)uF to ground (that one that leads to a 47 ohm resistor) switchable (gives a better volume boost). Replace output trannie with a 2N5488 if it´s a BF245.
Replace bias resisters for op-amp and trannie with 1M trimpots for finetuning of bias-points (decreasing this values will mellow the sound, around 800k for op-amp and 150k for trannie gives a good punchy sound).
Use a Voodoo Lab Pedal-Power or something similar
(10V DC, 150mA at least),´cause batteries are to weak for powering a RAT (increases punch, crunch and clarity).
You can play with the RC-Network that goes to the feedback-loop. Replace it with 1uF,100 ohm and replace the 3,3nF cap of the tonestack with a 10nF.
(reduces the fuzzy topend screech).