Man this hurts... I've been holding on to this pre-amp to use in a custom bass somewhere down the line, but I promised the wife I'd sell off all I could to buy my new F bass AC5. Here goes... This is a Bartolini DNTBT-18 pre-amp, most famously used in the Tobias Growler. It's an 18 volt system with tons of headroom. The controls are as follows: Vol, blend, front pick up Bass/treble (stacked knob), back pick up bass/treble (stacked), midrange switch for the front pick up, and midrange switch for the back pick up. There are internal controls to adjust the midrange as well. I also have all the standard plastic bartolini knobs to go with it as well. This is by far one of Bartolini's most flexible and best sounding pre-amps. The only drawback to this thing is that it's an incredible space hog. It's the equivalent of having 3 small pre-amp boxes, plus 2 9-volts, and all the associated wiring. If you can handle the space, it's worth all the routing you can handle! $110 shipped in the lower 48.