This preamp/booster pedal is inspired by the preamp section of 70s MusicMan amps. Those amps have opamps in the preamp, and EL34s in the power amp. Sometimes also a 12AX7 as the last preamp stage (one triode) and as the phase splitter (the other triode).
This pedal runs on 18V internally (+/- 9V) and has a copy of the MusicMan tone stack. Since it has a voltage doubler circuit, it must not run on more than 9V DC. The tone stack has Fender-like scooped mids, and the switch on the side switches between tone stacks from the “normal” and “bass” channel in the MusicMan amps. The switch on the front bypasses the tone stack and makes the pedal a very loud transparent boost.
Great pedal if you have an amp with quite flat frequency response and want it more Fender-ish. Or after, or before a dirt pedal to scoop out the mids. I use it when running through a DI-box and I want to tweak the sound some more.
The MusicMan amps were build in Anaheim, CA. That’s where I got the name from.