The MXR Bass Preamp combines a pristine bass preamp with a studio-quality Direct Out in a Phase 90-sized box, providing clear tone without hogging precious pedalboard space. Use it to add a new voice to an old passive bass, sweeten up any amp, or put some special sauce on a particular song. Dial it in just the way you want it and send it straight to the house pre or post-EQ with the built-in Direct Out. The Bass Preamp features separate INPUT and OUTPUT level controls and a 3-band EQ section with sweepable midrange from 250hz to 1khz for extensive tonal flexibility. It s all delivered super clean with high headroom thanks to our own Constant Headroom Technology , and you can use the PRE/POST EQ switch to set whether or not your Direct Out signal is affected by the Bass Preamp s EQ section. And of course, the Bass Preamp features a GROUND LIFT switch in case you encounter ground loop hum. The Bass Preamp is factory preset to operate in ¼ out buffered bypass and Direct Out active. For players who only want to use the ¼ out, there are two internal switches that disable the Direct Out and ¼ out buffered bypass for true ¼ out bypass mode.