converting s-tirg to v-trig with the CP-251

[godzilla]

or the other way round

as far as i can make out

S-trig
note off = +5 Volts
note on = 0 Volts

V-trig
note off = 0 Volts
note on = +5 Volts

So if you plug an S-trig out into the mixer of the CP-251 and plug its inverted output into another synth you'd get

note off = -5 Volts
note on = 0 Volts

if you then applied +5 volts of off-set you'd get a V-trig output

this is all just speculation, as i don't have a Cp-251 (yet) i can't verify if this works or not but i don't see why it wouldn't

[Duke Foog]

I thought and s-trig jack was a weird jack that moog used to use on their old modulars. i didn't think it was a quarter inch jack but a weird jack with two different size pins on it.

[eric coleridge]

A V-gate inverted would not be 0 volts, it would be negative volts. Most V-gates, I believe are around 8v. So, inverted it would be -8. And off, ground, would still be ground.

So, I think V-gate would be like:

+8 = on; inverted = -8
0 = off; inverted = 0

This, again I think, would cause a continuous On signal for an S-trig Moog.

The S-trig:

0, ground = On inverted = 0, ground
+5 = Off inverted = -5

This would result in no gate on a V-gate.

The problem is, the signals need to be offset, not inverted.
Also, the S-trig input usually only requires a voltage under 3V to trigger, and I'm not sure if negative voltages will work.

I think there might be some way to make this conversion work with the "Offset" control combined with the inverted output on the CP251.

The conversion from V-gate to S-trig can be accomplished using a simple circuit described in the MicroMoog user manual. It's only a few tiny components that can fit into a 1/4" cable.
Going the other way, S-trig to V-gate, is a little tricky.[/i]

[godzilla]

I think there might be some way to make this conversion work with the "Offset" control combined with the inverted output on the CP251.

if you look at my original post more carefully, you'll see the line about off-seting the inverted signal.

if you wanted to trim down that 8V signal you could do it using one of the mixers attenuators, but can the CP handle 8 Volts without gonig ?

[eric coleridge]

Sorry Godzilla, I didn't read you carefully enough. That looks right. Great idea.

I don't think the 8v would be a problem either.

[godzilla]

that's cool

[GregAE]

Why tie up a CP-251 to convert S-trig to V-trig? If you really have the need to do this, you'd be better off with a dedicated adapter cable as shown here:

http://www.synthesizers.com/moog_trigger-convert.jpg


For info on the various types of gates/triggers:

http://www.synthesizers.com/gates.html



Greg

[godzilla]

well i just thought i'd post the idea, as this is a forum where people are encouraged to post their new ways of using the foogers, if you don't like the idea don't use it.

also you might not want to get another bit of gear, you might just want to get the most out of your current setup, push the limits of what the 251 is capable of, it is a multi-purpose tool after-all and one of the functions of this forum is for it's uses to share some of the unknown uses for moog equipment

[eric coleridge]

I agree Godzilla, this is a really great application for the CP251, in case someone doesn't already have that S-trig/ Gate conversion circuit yet.

[godzilla]

cheers