Because of past talk about the Moog String filter and related stuff and Juergen Haible building a string filter, I figured I'd post an ad to an unknown string filter that I cut out of an ancient Contemporary Keyboard issue decades ago. According to somebody on I think the Virus list from a few years ago, only one was ever made and he ended up with it. Unfortunately he wasn't using it for its intended purposes but as a distortion unit he said. What a wasteful use of an interesting piece of gear. So here is probably the only time you'll ever see a picture of one in your life:
http://home.att.net/~elhardt/Formula_Sound_String_Filter.jpgEach filter has a 3 position switch under it, not sure what they do. I can only make out two of the knob labels, which looks like MODE on the 2nd knob, and RESONANCE SHIFT on the 4th.
-Elhardt