Rare 1980s analogue drum machine made in Japan by Electro Dynamics Corporation, the big brother of the Soundmaster SR-88. Four analogue voices: bass drum, snare, hi-hat and cymbal.

Comes with the original box, operating instructions and rhythm patterns sheet, which are hard to find for this model.

Current condition: powers up and makes sound, but has faults.

• Powers on, LEDs work, and it produces drum sounds
• The start button starts it, but stop doesn’t work, so it runs continuously
• Pattern selection and the mode slide switches along the top have no effect
• Tempo runs too fast; just about usable at the minimum setting
• Slight buzz on the output
• The 4 × AA/AAA battery holder is missing; the battery clip is present. Runs on 6 V DC

What’s been done:

• Opened up and checked by an electronics repair technician
• Power path checked and battery lead resoldered
• Board cleaned around the main EDC-1001 chip; the existing jumper wire has been checked and is fine
• All switches, jacks and pots cleaned with switch cleaner

The fault looks like it’s in the sequencer/control side, not the sound circuits. I haven’t investigated further, as there’s no service manual or schematic available.

Please note: by design, the unit only powers on when a lead is plugged into the output socket. This isn’t a fault.

A great project for anyone into vintage drum machines, restoration or circuit bending. Sold as seen.