Designed to provide electric guitarists and bassists with a safe and versatile method of exploring the full spectrum of bias shift effects, the FX953 Bad Bass Pedal from Rolls lets you easily under- or over-bias your instrument signals for wild new avenues of sonic potential. With the simple bias control knob, along with independent input and output level controls, you can easily achieve striking changes in sound quality without risk of damage to your circuits from voltage spikes. The internal Class-A preamp provides up to 43 dBV of gain, helping to maintain usable results even when bias shifts cause massive changes in output levels and distortion/breakup points. Activation is easy with a simple metal footswitch, and you can deactivate the effect without any fear of tone suck or signal loss thanks to the true bypass circuit. For bass guitars, you can replicate the distinctive tonal qualities of different bass cabinets with the 3-way low-pass filter that lets you select 500 Hz, 1 kHz, or 3 kHz. This American-made pedal can either run on the included 15 VDC power supply or a 9V battery (not included). Born from Rolls' extensive experience in biasing amplifiers and preamps, the FX953 allows you to intentionally over- or under-bias a circuit, delivering striking changes in sound quality. Initially tailored for bass guitar applications, this pedal is compatible with any guitar, making it an invaluable tool for shaping your unique sound. The custom-designed Class-A preamplifier meticulously emulates the characteristics of tube amplification under both over- and under-bias conditions. Box Contains Rolls FX953 Bad Bass Preamp Pedal 1x 15 VDC Power Supply