Never used Beta Custom Shop LM308 Mosfet bass pedal. This thing gets some righteous distortion! Description from SolidGoldFX below: The Custom Shop Beta LM308/Mosfet is a hot-rodded version of our Beta bass overdrive platform. Featuring our JFET preamp and built around an LM308 Op-Amp, this variation is tuned for a higher gain drive section, slightly flatter mids and lows, and plenty of spongy, round compression. The addition of Mosfet and NOS Germanium clipping further enhances these characteristics, giving this version of the Beta plenty of saturation and sustain along with a pleasing smooth attack that really encourages you to dig in. If you are looking for a great bass drive with a touch more heat than our standard Beta and the classic LM308 flavor, you will enjoy the Custom Shop Beta LM308/Mosfet. Level Control: Allows you to increase or reduce your volume level. Drive Control: Allows you to increase or decrease the amount of Drive. The tone will get slightly brighter, as you increase the level of distortion. Tone: Allows you to adjust the amount of bass or treble content.