[AH] Drum trigger for ARP Odyssey?

[Ken Balys]

If you wanted to do this right you would build an audio threshold
detector that you could plug any mike into and then produce
the correct trigger pulse using a monostable circuit so that
the trigger is debounced and has a regular pulse width.
This would be a simplified version of an LED VU meter circuit
except it would only have one LED that would light up only
past a certain audio amplitude. This signal then goes to
a 555 timer monostable that generates the standard +5V 1->2ms
pulse (or whatever).

I built a circuit to do exactly this with a slider for the
threshold. Components were a 555 timer for the monostable and
a 741 opamp for the audio trigger.

These circuits are the basics of most analogue circuits so
if you head down to the local university library and look for books
called "Electronics Cookbook", "Basic Electronics", "555 Timer
Cookbook", "CMOS Cookbook", "101 Electronic Projects",...
you will find many schematics that you can adapt to this.

(cost of such a circuit should be around $3 + about
$7->$10 for the case, jack and battery clip)

Cheers,
Kenny B.

> Years ago I saw a guy epoxy a small radio speaker to the underside of a
> congo drum head.  The idea was to use this as a simple pickup for a
> trigger mechanism.  The leads from this speaker he fed to some kind of
> bread board which he used to trigger his ARP Odyssey for drum effects.
> Does anybody have schematics for this kind of bread board?  Would just a
> Trigger work, or would there need to be a CV voltage too?