Rare vintage distortion/sustain pedal from Roland released in 1973, which was Rolands first year, this one has a Multivox sticker on the back for the serial number. Multivox had a long relationship with Ikutaro Kakehashi (Roland founder) as they imported Ace Electronic Industries products, which was the previous company founded by Kakehashi.
This unit has been serviced by our tech, here are his notes: Replaced the 9v clip, cleaned all controls, disassembled and cleaned footswitches and rotary (mode) switch. Replaced (1) tantalum capacitor. Identified version and PCB *old version with "module" pcbs. Modules are made using discrete transistors. Does not use Ic's.