Simple VCO

[Tom May]

Hallgeir Helland <hhelland at mailandnews.com> writes:

> I need suggestions for a simple VCO circuit. V/oct.
> 
> The good part is that it doesn't need to cover more than
> about two octaves.
> 
> That, what was it, the MS20 VCO; will that be good for a
> bass pedal synth, d'you think?

That one uses thyristor-connected transistors to reset the integrator,
right?  That seems pretty elegant and I tried it out a while back and
of course it worked but I always wondered if there were any bizzare
temperature dependencies or if they magically cancelled out or what,
and was too lazy to try to figure out how the thyristor thing worked
al all let alone try to figure out how it responded to temperature
either theoretically or by pointing a blow dryer at it.  I do know
that when I poked it in the wrong place with a scope probe it stopped
working.

Maybe this has been thrashed out while I've been gone, but what kinds
of advantages/disadvantages does this reset circuit have?  The parts
count is pretty good.

Tom.