THROD

THROD-a Hybrid-analog synthesizer built, and completed by Rich O’Donnell in 1974. Some SSM chips, Emu sub-modules, Electro-notes schematics, and some self designed circuts complete the workings. Forty-eight 8:1 multiplexers, (4051) allow patches to be set, in milliseconds by sending a 128 bit word to the patch bay. Patches could be changes at audio speed. I’ve never heard anything else like that.

A closer view of some of THROD’s panels. Aluminum, sprayed white, lettered with press-type, and clear coated for protection. The finish has lasted over 40 years.

An I/O box, (RO designed and built DACs), that provides 12 analog output voltages, and 8 gates. 8 bit words that “feed” the DACs, as well as the patch 128 bit words, were provided by a Commodore 128 computer; running in assembly language. In 1976, with so little RAM, I never ran out!

Other control voltages were provided by a custom designed analog sequencer, and a four track digital sequencer. The original keyboard, not shown, had no keys, but was touch sensitive.