[sdiy] ASM-1 VCO section update

[Tom May]

"Tony Allgood" <oakley at techrepairs.freeserve.co.uk> writes:

> Magnus>Hoy! Tony! Do you recall the discussion we had on sync over at
> Paul's?
> 
> Yes, I remember it. I use a similar method to the ASM VCO in my own VCO
> design. Although I use a diode to clamp the negative going spikes to
> prevent any change in threshold in the comparator.

I tried that and the glitch was still too noticeable, which led me to
design the wacky circuit at http://www.you-bastards.com/asm-1/vcosync.gif.
It has the further advantage of not being dependent on the slew rate
of the sync signal, and not loading the sync signal.  But it is wacky.

> But I still find that triggering from another VCO's Sawtooth output
> gives a much better sound at lower frequencies. Using a square does
> sometimes result in 'slipped' sync, a bit 'soft' if you like. At higher
> frequencies the two are similar.
> 
> Regards,
> 
> Tony Allgood  Penrith, Cumbria, England
> 
> Oakley Modular Synth and TB3030:
> www.techrepairs.freeserve.co.uk/projects.htm
> My music: www.mp3.com/taklamakan

fTom.