This is a bass preamp built off of the design first used in the Traynor TS-50b amp which is also used in the modern Rusty Box preamp. This is a very unique and colorful preamp that distorts high, mid and low EQ bands separately. It's not the best for clean tones but what it does, it does very well. My version runs off of 12v DC and it was built for Brian of Aseethe.