Rolls FX953 Bad Bass Preamp PedalDesigned 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