I just got an old weird custom built bass as a present and I have found a 3 band pre amp in it. marked on the PCB as: IN Yeon Industrial,Co.stp 001amp. Anyone know anything at all about this pre amp?. It is connected to a stingray 5 pickup of some description (probably Nordy?) It seems to work ok and is very quiet signal to noise wise, I am just interested in trying to find out anything I can about this setup as I may want to modify its caps a bit, to bring down the frequency of the treble shelf band a bit as I would like it to pick out a bit more "clank" than "bing" if you know what I mean.