This pedal combines a three-control blues driver circuit with two switches to adjust Drive and Tone characteristics. Robert and Andy developed these switches to offer musicians a wide variety of drive tones. When the Tone switch is up and in the AT position, the tone control presents EQ with Andy's preferred bass response. Each note of a chord is clear and articulate. If the Tone switch is down and in the RK position, the legendary Phat Boost is activated, providing a lower frequency response ideal for boosting vintage or single coil pickups. The MUSE DRIVER circuit combines JFET saturation, diode clipping, and op-amp clipping to create this harmonic-rich tone. Drive switch high for AT Clipping: This mode features asymmetrical clipping with LED and silicon diode, which is Andy's Super AT Mod sound. Drive switch low for RK Clipping: The circuit uses two germanium diodes for clipping, and this mode can sound like a vintage fuzz pedal with a smoother, velvetier feel. Main features: • Classic blues driver circuit with decades of Keeley modification experience • Germanium-based overdrive designed under the direction of Andy Timmons • Tone Switch o AT: reduces bass for clarity o RK: ​​increases the bass for more power • Drive Switch o AT: asymmetric clipping with LED and silicon diode o RK: ​​two germanium diodes: softer, velvety feel with almost fuzz characteristics • Selectable Buffered/True Bypass switching • 9 to 18 volt operation for wide dynamic range and headroom • Made in the USA.