OT: adding a pulse width modulation LFO to an existing square wave oscillator?

[axg20202]

A bit OT, kind of.

I have a monosynth that can already generate square wave, but I'd like to modify it with an additional PWM LFO, probably in a stompbox-style breakout box. Can anyone point me to some circuit diagrams that would help me to add this as a bolt on to an existing VCO?

[slacker]

What is the oscillator? Adding PWM might be anything from very easy to virtually impossible.

[axg20202]

In this case, its a moog minitaur. i havent got under the hood of it yet to see whats what - SMD aplenty I expect - but it might be possible....

[moosapotamus]

Just for clarification, are you looking to 1) modify the monosynth's existing (internal) LFO to add PWM, or are you looking to B) add another (external) LFO that has PWM capability?

Either way, if you haven't already, you might also want to try your Q at http://electro-music.com/forum/

~ Charlie

[axg20202]

I'm thinking it might be wiser to add a new LFO specifically for PWM duties, leaving the existing LFO alone so that it can still modulate the filter etc. as normal. There is only one on-board LFO, so adding one might give more flexibility. However, the internal LFO responds to midi to control rate and depth, so it might be cool to use the one board LFO.

Thanks for the link. Have posted there too.

EDIT:  also, its worth noting that the internal LFO is applied equally to both VCOs in the minitaur. Not sure whether it would make sense to have a similar implementation with the added LFO or to have the new LFO switchable between the two VCOs or simply available for one of the VCOs only. ??