fonik's Jim Patchell Vocal Filter

I ran across an old thread from 2009 via fonik on electro-music.com.  I couldn't find a post here, so I thought I'd put one up.  I did get the start of it on flickr here. Below is a demo and to the left you'll find two pics, one of the front and one of the inside.  See the link above for additional details and demos.

"Recently i stumbled over Jim Patchell's Vocal Filter. i listened to the samples at his site which are amazing. these samples convinced me to want this filter. so i downloaded the gerber files and sent them to futurlec. they made this PCB for me (below). it's a huge project. i will keep you posted... "

VocalFilter 2 by fonitronik
"Klee2 Sequencer controls VCO and Vocal Filter to create a nerveous arpeggio. Some tracks added to show how it could sound in context."

via Jim Patchell's site:

"This is yet another huge project that I am working one. It was not intended to be huge, it just happened that way.

I would classify this as an advanced project. This is not for beginners. There are 479 components on the PC board (at the current count).

This filter was designed to simulate the vocal tract of a human. To do this, there are three resonant filters that will be tuned to different frequencies. To make it so that the phonems can be selected via voltage control, there are three CV shapers on the board. These will allow you to make a more or less arbitrary function to control the filter frequencies. Now, I will be the first to admit that setting the function generators up is going to be a big pain in the ass!, and to do so will require the use of a scope with X-Y display capability.

Now, as of today (7-3-2001), I have not really tried this circuit out. Now, I did another breadboard of a simpler circuit a while back (you will find it elsewhere on this website), and the results were encouraging, but, not very spetacular. And, with 479 components, I am not sure if I want to build up a bread board, and due to layoffs at the place I am working, I have imposed a spending freeze, so PC boards are out of the question. So, for right now, this project is on hold due to lack of funds. As soon as I get the PC Board layout done, I will post the gerber files, and maybe some other brave sole will give it a try."