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How to reset phase (hard sync) on an oscillator with another oscillator?

+1 vote
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I'd like to do something like oscillator sync on the analog oscillators where one oscillator forces the other to reset its cycle.

Kyma oscillators (or OscillatorTimeIndex) have Reset but it appears to be a capytalk rate trigger, and I'd need audio rate to do the Phase Sync stuff.
asked Sep 15, 2017 in Using Kyma by cristian-vogel (Master) (6,710 points)
Is the controlling oscillator a pulse? Or is the reset when the control oscillator crosses zero? In other words, what condition in the control oscillator signals the phase reset in the audible oscillator?
It depends on the analogue oscillator. Some have a comparator at the input so pretty much any signal will suffice. Usually anything but a sine wave will do the trick. There are also different ways of reacting to the sync if the oscillator is derived from a sawtooth or a triangle wave. In the first case it resets in the latter it reverses. Here is a link with some info on this: https://sites.google.com/site/watkinsmodularsynthesizer/vco-sync-study

I'd like to see it be implemented as well btw, it is a cool function to play with :)

1 Answer

0 votes

I think I've worked out how to do this by using an OscillatorWithTimeIndex and manipulating the OscillatorTimeIndex that drives it. 

(Correct me if I've got this wrong...) A hard synced oscillator would reset early before it has completed its full cycle (creating a nice discontinuity). 

If you attenuate the output of the time index Sound then the oscillator it drives resets before it reaches the end of the wave. 

Here's a trace of the index signal (top) and a sine wave oscillator that's being driven by it (bottom). 

The Sound looks like this:

It doesn't "feel" like resetting one oscillator with another (and I haven't made it convenient to specify the syncing in terms of two frequencies of two oscillators) but I think the outputted waveform is the same. 

Here's the Sound.

 

answered 5 days ago by alan-jackson (Master) (9,330 points)
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