The Ultraphonix Overdrive is designed to re-create the overdrive produced by a Dumble™ Overdrive Special amplifier. Using a sample size of four generations of Overdrive Special amplifiers from 1970-1990 to voice and calibrate the pedal, the Ultraphonix is more than able to provide the D*style overdrive to any clean amp platform. THE FEATURES INCLUDE: Voiced alongside four Dumble™ ODS amps ranging from 1970's-1990's Quintessential D*style tone, note bloom, & harmonic overtones 100% Analog Circuitry Mechanical True Bypass Switching Designed & Assembled in California 9VDC center-negative power operation (adapter not included)