From piero@cabernet.stat.unibo.it Thu Aug 24 09:54:24 1995
    24 Aug 95 12:54:05 +0500
    17 Aug 95 16:55:39 +0500
Date: Thu, 17 Aug 1995 22:29:00 +0200
From: piero@cabernet.stat.unibo.it (Piero Cavina)
Subject: cs30 squencer trigger in

Hi folks. I have found a simple but effective way to syncronize
the cute little analog sequencer of my Yamaha CS-30 to any external
trigger signal.
Maybe this can be useful for some of you...

What you need is just a tester and a short electrical wire.

We're going to use the CS-30 signal processor.
The CS-30 has an external signal input. It can be used
for signal filtering, as a modulation source or to trigger the envelopes.
Each envelope has a switch which selects the trigger source:
keyboard, internal sequencer, or external signal.
Turn the switch of any envelope to EXT. Feed the external input
with a trigger signal, (the old drum machine trick works, but use
a sound with short decay) adjust the trigger level/signal level knobs,
and watch the envelope LED blink.

I haven't the schamatics for the CS-30, so I had to use
the pulse signal which lights the LED to advance the sequencer.
Probably this isn't the best solution, but it works...

Turn the Clock/Manual sequencer switch to Manual. Now, the sequencer
advances one step each time you press the Start/Stop button.

Turn off the CS-30 and open it (you'll have to remove the side panels
and to tilt the front panel).
Locate the Start/Stop button: two wires are connected to it.
One has +15VDC on it, the other is the sequencer trigger input.
Use your tester to find which one is the trigger input.
You can use the metallic case as a ground point. Be careful,
because if you choose the +15V instead, you are likely to damage
something.

Each envelope LED is mounted on a small PCB which looks more
or less like this:

      ================
      I              I
      I (X)    o---\ I <------ wire the sequencer trig input
      I       LED  ! I         to this LED pin.
      I        o-\ ! I
      I          ! ! I
      I       /--/ ! I
      I  /---/     ! I   
      I  !     !---/ I
      I OOO   OOO    I
      I OOO   OOO    I
      ================
      
Turn everything on... and if that smoke comes from your cigarette,
everything should work.

Remarks: 
1) maybe connecting the LED with the sequencer through a diode and
a resistor would be safer;
2) better add a switch to disable this feature;
3) now, if I had the schematics...


Bye,
Piero Cavina

PS: I'm not on the list, I just read AH digests monthly.
If you have any question, please email to:

piero@cabernet.stat.unibo.it

Mike, Todd: archive this message if you think it's useful (and its
english isn't too much Roland-esque...)