Sync-ing Vox Repeat Percussion - can it be done?

[RandomGlitch]

Hi,

I've just built a Vox Repeat Percussion, tremelo effect.  It works well and sounds great.

What I'd like to do is synchronize the tremelo to a drum-machine, somehow, so that it stays "in time" throughout a song.

Maybe by taking one of the drum sounds from my drum machine (a side-stick click perhaps) as a "trigger"

Can this be done do you think?

I'm using this circuit:



Thanks!

[R.G.]

Can it be done? Sure.

It may be tricky. If you have a steady trigger, there all the time, you can do a variant of either an analog or digital phase locked loop. If the rates of the trigger and desired rate on the repeats is not 1:1, you get into some divider/multiplier setups on the phase locking. Not too difficult, but it affects the time to sync and follow changes.

If you have an intermittent trigger, it gets tough. Then you have to have some way of constructing a constant (or slowing varying) rate out of the intermittent triggering. That is technically tough to do right, although you might get it to work well enough with simpler means.

The reason this comes so glibly to me is that I designed a trigger/beat following setup that was made into a commercial product last year. I ran into many of the pitfalls.

If your drummer is not adverse, it's very much easier to feed a constant trigger stream (click track) to both the repeat percussion and the drummer to keep them in sync. Human drummers are not always steady.

[RandomGlitch]

That's essentially what I want to do - send the drummer and vrp a click. With my
Recording setup it shouldnt be too hard to send the drummer a 4 beat click
and the vrp double that, for instance. I guess I can look up those terms you said
and figure something out. Thanks!