A/DA MP-1 Channel Preamp Pedal Selected, dual high-gain, low-noise 12AX7 vacuum tubes OD1 and OD2 dual Drive controls for smooth overdrives to crusty distortion 270 volt internal power supply from a standard 12VDC AC Adapter (AC Adapter included) The famous ADA Tone Stack includes a PRESENCE control for glassy definition CLEAN and DISTORTION Voicings