I use these on Les Paul®s, Strats and Telecaster® with equally breathtaking results- First of all you've got a nice fat bottom boost that turn a Fender® into a Gibson®, then as you turn the dial you begin to get the classic "Tube Drive" gain and mid boost- as you turn the knob up you get even more boost and a nice 3 dimensional expansion of highs and lows. Play this through a 4-10 Bassman with a Strat and it's just this ten foot deep- walking on clouds- Stevie Ray sound.
The Mini Expander Circuit runs on a single 9 volt battery, and battery life is excellent. The unit has it's own push-pull pot built in- Pulled up you've got a stock guitar- NO CHANGES to the sound- Pop the knob down and the effect engages.. I've sold a ton of these- and retail is $79 for the "Mini Expander" circuit and $50 for installation. I'm including my easy-to-follow installation instructions, as well as a 9 volt battery clip. All you need is a small soldering iron and a guitar!
This is a must-have device. I've put em in $350 Mexican Strats and into $2600 PRS Artists- everyone is always amazed at how this circuit makes any guitar a versatile rock machine.