I saw my name mentioned in this thread so I'll respond.
>>Anyone with pointers as to how to get started designing sounds for breath controllers would be greatly appreciated by me, too. Specifically, any recommendations as to which modules I should include in my MOTM rig?<<
I was using a Yamaha BC-3 breath controller going through the VL70m which would insert breath control info into the midi stream from my keyboard. Then that would go into a Kenton midi to cv converter where I could get the breath control as a voltage. It sound control loudness and brightness of the sound if not other things as well. This is where I needed an MOTM lag processor module to smooth out the digital midi voltage stepping, otherwise it sounds awful.
Since then I bought a second MOTM pedal interface so I could install Larry Hendry's breath control add on. I've put in the jack and bought all the parts, but haven't done it yet since he appears to be using voltages that aren't what the BC-3 specs say it wants. I need to modify it first. However, since that takes the use of Midi out of the chain and it's all analog, the lag processor shouldn't be needed unless you want to smooth out your human inflections.
If you're also looking for tips on synthesizing a brass sound for use with breath control, one problem I needed to try to solve was destinguishing the attack of the sound so I could synthesize a better brass attack. I needed some kind of differentiator module. Just my preliminary test seemed to show that you can use a module that has an AC coupled input such as a mixer module. A fast blow into the breath controller with part of its split output sent through an AC coupled input can give you a voltage bump with which you can use to add the initial brass gurgle type sound. The faster you blow the higher that voltage spike and the more of that brass gurgle type sound you can get. I was able to accurately simulate the attack of a brass instrument using a short burst of variable rate FM on the attack. Most of that experimentation was done on the Nord Modular though, but I do have one MP3 online where I spliced a synthesized french horn several places inbetween a real french horn to see how convincing my attacks matched up. Even I have a hard time telling fake from real. Sound file is here (224K in size):
http://home.att.net/~elhardt3/Horn_Real_Fake_Interleaved_FFT.mp3There's no high frequencing audio in the file as I chopped it off with an FFT filter so the horns would sound similar since I hadn't worked on bright french horn sounds yet.
-Elhardt