Placed an order for a Synthesis Technology MOTM-650 MIDI/CV converter today, to take advantage of their end-of-year sale. The 650 is just what I need to bring flexible MIDI control to The Discombobulator. I like the idea of being able to drive a lot of different control voltages with the sequencer, and with the 650, you can get up to 12 control voltages out -- a pitch CV, velocity CV, and aux CV (assignable to a MIDI continuous controller) for each of four channels. After thinking some about where to mount it, I'm going to build a fourth block, which will contain the 650, a pair of envelope generators, and a VC panner, along with perhaps a mixer and whatever else I can fit in. This block will serve as the modular's primary interface with the rest of the world, taking MIDI from the sequencer and sending audio outputs to the mixer.
Procuring the 650 will allow me to dedicate the JKJ Electronics (RIP) CV-5 to the EML 101. For the past several years, the CV-5 has done double duty, interfacing to both the 101 and the modular. This has been a pain because the EML uses 1.2V/octave scaling, so every time I move it from one to the other, I have to re-scale it. There are, however, a lot of convenient features about the CV-5, which I'm going to have to work a bit to get the 650 to do the same things. One thing I appreciate about the CV-5 is that it contains a built-in MIDI-controlled panner; you plug in a mono audio signal, and it produces a stereo out. The panning is contolled by the MIDI Pan continuous controller, and it's internal to the interface. This is nice for automating panning during mixing; I do a lot of virtual-mix techniques, and to make that work you need the mixdown to be absoultely as automated as possible.
Other handy features of the CV-5: It processes pitch bend messages and adds or subtracts pitch bend from the pitch CV output, and you can set the bend range via MIDI. It also has a built-in LFO which can be added to several of the CV outputs, and the LFO can be sync'ed to MIDI clock. (It also has the ability to convert MIDI clock to DIN sync, but I don't use that.) A built-in portamento can also be programmed via MIDI and added to the pitch CV output, and there are several choices for note priority, velocity and aftertouch routing, and gate/trigger modes. (This includes S-trigger output, which is another thing I don't use since I'm not driving a Moog with it.)
Those are the sorts of things I've been looking for in a replacement for the CV-5, and the 650 fills the bill. Plus, it is of course built in the MOTM form factor, which the CV-5 is not. And, the 650 has lots of additional goodies, including built-in sequencing, microtuning tables (which work by offsetting the pitch CV output depending on what note is played), and the ability to update the firmware via MIDI. One little glitch is that there is an updater program for Windows and Mac OS9, but not OSX. I'm going to ask Paul S. if he's willing to document the updater protocol; if so, I'll write an OSX updater program and give it away to other 650 owners under GPL-type terms.