[sdiy] Roland drum trigger spec's

[Colin Fraser]

> -----Original Message-----
> From: owner-synth-diy at node12b53.a2000.nl
> [mailto:owner-synth-diy at node12b53.a2000.nl]On Behalf Of
> nss at hevanet.com
> Sent: 13 March 2001 22:58
> To: synth-diy at node12b53.a2000.nl
> Subject: [sdiy] Roland drum trigger spec's
>
> A couple of months ago I made a copy of the 808's tom/conga section.
> They are pretty much straight clones, the only difference
> being I used a
> tl082 instead of original.

I did much the same.

> But they all had a problem. The pink noise
> would not make it to the output. I copied the original noise
> generator,
> and it seemed to be putting out the correct voltage, but no
> mater what I
> played with it still would not work right.
> 	Then I remembered someone saying that the Roland
> trigger is suposed to
> be a 10ms pulse and some sounds would not work right if this
> was varied.
> I am using a PAIA midi-cv that puts out a 5ms pulse. Could this be my
> problem????

The 808 uses 1ms, 5 volt trigger pulses, and accent CVs between 4 and 14
volts.
But using a 5ms pulse shouldn't stop the pink noise working.

Disable the twin-t oscillator by removing the trigger input cap to it (C86
in the mid tom) and see if you are getting no noise, or just very quiet
noise.
Remember the original noise content on the 808 toms is very quiet anyway.

Colin f