Wilgamat

Back in 2004, I was looking for a portable auto-accompaniment drum machine that generated chords and bass lines much like those home organs that were so abundant in the 1970s. On a combo-organ forum, someone suggested the Elka Wilgamat. I was able to find one on ebay that didn’t make any sound, but appeared to power up and run just fine. I believe I paid $50. It’s a Wilgamat III from 1982.

There is a Keyboard interface on the Wilgamat. When a keyboard is attached, the operator can generate chord progressions by shorting the note pins to ground. I was able to reverse engineer which pins activated which notes, and get sound happening after bypassing the LV pin for volume. There’s a lot to learn from the Service Manual!

There are 16 preset rhythms, and there are 4 sounds in the auto-accomponiment section: Brass, Bass, Piano, and Arpeggio. The Drums are divided between two parts.. One more for cymbals and high hats, the other for bass drum, snare, toms, etc. These sounds are adjustable via a small mixer section.

I took those pre-fader signals from the mixer section, as well as the two drum parts, and made them individually patchable. I also added a new sound I called “Synthi”. This is 4 different octaves of square waves available on the bass circuit. This sound follows the bass line, but several octaves higher. The octaves are selectable from a rotary switch.

The keyboard I used comes from a Casio CT-310 that I modified to bridge each key to a ground bus. I built a wooden case to house the Wilgamat, the keyboard, and the breakout sounds so it’s all one unit.