Dewster asked: "I'm curious, have you ever examined the MIDI stream coming from it?"
When Bob Moog built the MIDI Ethervox back in 1996, there were no commercially produced MIDI receivers that were sophisticated enough to be controlled by it. The Ethervox is actually two instruments in a single cabinet: a traditional heterodyne theremin, and a MIDI gestural controller that can operate in 4 different modes. It has two entirely separate voices - VOICE ONE is the heterodyne theremin, VOICE TWO is a synthesized theremin sound like the Moog SERIES 91 instruments, the Moog THEREMINI, and others (which are not heterodyne). VOICE TWO is used for playback (via MIDI IN) when the MIDI Ethervox is recorded to a sequencer.
The Ethervox CHROMATIC MODE is able to send note on/note off commands to a MIDI receiver in user programmable configurations. This allows a thereminist to use the Ethervox as an instrument of accompaniment. The effect is quite stunning!
Although there were no sufficiently advanced MIDI receivers back in the 90's able to read pitchbend info over a nine and a half octave range, now there are. The Haken Continuum can talk to the E'Vox - no choking, no freezing, no zippering - and there may be other devices I am not familiar with that can communicate with it as well.
Yes, I have examined the MIDI stream coming from the E'Vox, and have recently had extensive communication with Rudi Linhard (of LINTRONICS) who is the designer of the E'Vox MIDI software. Rudi is a super guy, and he ironed out a couple of bugs in the MIDI software that should have been taken care of years ago, but they were never identified until now because nobody (other than yers trooly) was using the MIDI capabilities of the instrument. The board uses the old EPROM technology, so there was a lot of back & forth, burning and testing various new versions of the software before things got fixed.
Randy George has developed a software (MIDI Merlin) that is capable of accepting audio input from any theremin and delivering MIDI output. I have had limited experience with this amazing piece of engineering and it is WONDERFUL.