Wilgamat III v3

This is the third Elka Wilgamat I’ve modified since 2005. The Elka Wilgamat III was an Italian built “Groove Box" from 1982. It has preset rhythms, and it will play bass lines, arpeggios, horn lines, and other auto-accompaniments via a keyboard attachment. Since the keyboards are often missing, I came up with a way to activate these features using key beds from old keyboards. The first two I modified use a Casio CT-310, and this third one uses the key bed from a 1986 Yamaha PSR-12. To make those keyboards work, the switch matrix needs to be rerouted so that each key will individually switch to a common ground bus.

Like the other Wilgamat mods I’ve done, this one has switchable breakouts for the individual sounds. Six of the sounds come from the mixer section (bass, brass, piano, arpeggio, drum1, drum2), and a bonus sound called “Synth”, which are 4 selectable octaves of square waves that follow the bass line. Unlike the other Wilgamats, these sounds are accessible from a DB25 that breaks out to seven 1/4” cables.

The individual sounds can be turned on and off from the illuminated switches on the keyboard. There is also a 4 position rotary switch for the Synth octaves. The keyboard unit itself is made from Ash and Walnut that I cut on my CNC mill. A 50 pin SCSI cable connects the keyboard to the Wilgamat. This sends the 24 note switches from the keyboard, as well as 5V, ground, and the control signals. On the top part of the keyboard, there are momentary switches to activate Fill, Minor, and 7th. I also added “Roll” switch that taps into the internal programming to create a drumroll on the snare, and is not a standard feature. The Fill, Minor, and 7th is normally accessed through an optional foot pedal.

I replaced the original, proprietary Keyboards connector on the back with another 50 pin SCSI. Inside of the Wilgamat, I built a switching circuit to route the individual sounds to the DB25 and activate the Fill, Minor, 7th, and Roll. All switching is done using 4066 ICs. The 4066s switching audio are powered +/-5V.

I also installed a Tubbutec uniPulse on this version. This allows MIDI control for clock, as well as nine drum triggers. I repurposed the built in Rate Equalizer switch to act as Internal/External clock selection. Interestingly, the Clock Output 1/4” will output a square wave sync signal in time with either the internal 555 based clock, or the MIDI clock. The uniPulse is set to 24 PPQN.