This project was partly inspired by the Vocal Filter in my Nord Modular and the Speech Synthesizer kit that I aquired (as a collectors item) that was put out by AT&T (no longer my favorite long distance company, nobody can justify $5.00/minute long distance rates). Well, actually it was Bell Labs (now Lucent), but I had to get my rant in there somehow.
What you see here are sketches I have made for making the breadboard. I had hoped to have it done in 2 days. Here it is, going on 11 now, and all I have done is the function mappers for the control voltage. Although, this was the most difficult task, or, at least I hope that was the most difficult task. I have never built peicewise linear diode functions before, so, it was a new experience for me. My first effort, while it worked, did not work very good. I got out my Analog Devices NonLinear Circuits handbook, and the good book showed me the way.
Well, I finally got the prototype finished. Here is a photo of the board:
Thing has more parts than a lot of synthesizers!
Here is an MP3 file. It is kind of big because it is 256KBPS. 128 sounded real strange. Guess it was one of those waveforms MP3 has a hard time with.
Vocal Filter MP3 (3.5MB)
Anyway, here are my notes from so far: