Synching a Vortex?
n9540283 at gonzo.cc.wwu.edu
Fri Jan 31 06:38:08 CET 1997
Hi Gene, I thought I would let you know that I would also be interested
in a circuit like this if you decided to think one up. There's probably
quite a few people actually.
On Thu, 30 Jan 1997 gstopp at fibermux.com wrote:
> I think you are on the right track...
> It is distinctly possible that the Vortex tap footswitch input is
> looking for a short to ground as the trigger event, in which case you
> could skip the relay idea and just use the transistor to ground the
> input (like a Moog S-trigger). To turn on the transistor you could use
> a voltage trigger from a MIDI clock-to-voltage pulse converter, or
> like you say derive a pulse from an audio event such as a drum hit.
> Converting the audio pulse to a voltage trigger can be done with an
> envelope follower plus a comparator. Actually for such a specific
> application you can probably throw together a simple
> diode/cap/resistor peak detector into an op-amp into the transistor
> and be done with it. Probably you'll need a 10x preamp on the front
> end. It might have to be tweaked to the specific drum sound that you
> use, but since the Vortex is expecting a "sloppy" pulse like a human
> foot on a switch, it probably doesn't care too much about pulse
> The way I'd figure this out is with a protoboard, an assortment of
> components, and a scope. Hey I have a Vortex now, maybe I'll check
> this out some time (next week at the soonest...).
> A couple weeks ago I built a MIDI-clock to voltage pulse divider
> circuit on a single chip, but that's another story...
> - Gene
> gstopp at fibermux.com
> ______________________________ Reply Separator _________________________________
> Subject: Synching a Vortex?
> Author: "Arnim X. Sauerbier" <arnims at usa.globelle.com> at ccrelayout
> Date: 1/30/97 6:06 PM
> Hi folks!
> Not a synth question, but a musical DIY topic nonetheless:
> I've got a Lexicon Vortex (worth the $149 sale price IMHO). It lets the
> user set delay times by tapping a 'delay/tap' button twice. The box has
> no MIDI interface, but I'd like to sync the delays to my MIDI sequences!
> I was thinking of the following hack: use one of the outputs of my drum
> machine as a click, then build some kind of circuit that closes the
> contact of the 'tap' switch whenever a voltage peak (from the drum
> machine) is detected.
> What would such a circuit look-like? Perhaps a transistor that triggers
> a relay that closes the 'tap' button?
> What would you do? Any other solutions that wouldn't involve using-up an
> output on my Drumstation?
> Thanks! Sorry for my glaring ignorance.
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