[sdiy] noise maker ...top octave IC

[PRCamann at aol.com]

Okay, for real TOG mayhem:

First, look at these:
http://hammer.ampage.org/files/Marston's4046circuits.PDF

Next, in the circuits for frequency synthesis, substitute the top octave generator for the divider circuit (e.g., the 4017).  VCO output goes to the input of the TOG.  Phase comparator input can come from any of the divided outputs.  If you pick the lower C, you get a full octave of notes above your input pitch; the upper C, you get a full octave of notes below your input pitch.  Pick any note in-between and you can build chords using notes both above and below your pitch.  Change pitch and the notes move with you.  Add waveshaping or other post-processing if square waves aren't to your liking.

Use of a 4024 7-stage binary divider in the same circuit, with the divide-by-16 output used for the comparator input, gives 3 simultaneous octaves above and 3 simultaneous octaves below the input pitch.

Use programmable dividers (4029 or similar) in the feedback loop and at the output for perverse frequency ratios or just intonation.

Absolutely nasty when used with a properly processed input instrument (processing as used with octave dividers -- compression, filtering, etc.).  Wonderful with an electrified trumpet...

The 4046 PLL has been one of my favorite ICs ever since the mid '70s.  The above circuits are why.

Paul Camann