audio to gate trig device?

[lazydog]

just wondering if there is a simple/inexpensive circuit for producing
a gate trigger pulse from an audio trigger.
eg: producing gate pulses from a drum machine audio output.
(and then about multiples, for a multi-out drum machine)

main idea being to be able to build gate-triggered drum modules and
trigger them from a midi drum machine.

[voodoolikeudoo]

Is this what you're looking for?

[DDama]

Could I possibly use this with a Roland TR-8?

[voodoolikeudoo]

I haven't built it.
Circuitbenders do a kit for that though http://www.circuitbenders.co.uk/forsale/audio2trig/audio2trig.html