[sdiy] Simple MIDI-syncable LFO...?

[WeAreAs1 at aol.com]

In a message dated 10/18/04 1:56:42 AM, ifrc at iar.se writes:

<< Why not make a regular analog LFO that is reset every NNth MIDI clock
message? Keep the LFO rate knob and use it to adjust the waveform. The WASP
LFO is very simple and has at least 4 different waveform outputs.  >>

Yes, this is a good idea.  The ARP Odyssey LFO circuit has a very simple and 
effective reset/sync input that would probably work great for this.  I think 
you can find the Odyssey schematics out there on the web.  I would use one of 
John Blacet's MIDI Clock PIC's, and divide the clock down via some simple CMOS 
counter circuitry.  If you went with this method, you would have to manually 
adjust the LFO's rate to be close enough to your target rate so that the sync 
pulse would not drastically alter the LFO's output waveshape (unless you liked 
that effect...).  Once you get the speed close, the divided-down clock pulse 
would keep the LFO in sync with the incoming MIDI clock.

I think that a simple old analog LFO would be much more practical and 
smoother-sounding than some kind of digital LFO (as was suggested by a few other 
people), plus, it would be decidedly easier to build and control.  

Michael Bacich