[sdiy] DR110 repaired, possible trigger ins?

[Dave Magnuson]

At 08:07 AM 5/3/04 -0700, you wrote:

>I have been trying to put trigger inputs to
>the drum voices. I made a piezo trigger extractor years ago, which i
>unpacked and set up. Putting 5v triggers into the DR110 did not yield
>any interesting results.


A positive trigger or gate will not work on the DR-110.  The trigger lines
are held high (+6v) and shorted to ground to make the voice sound.  I used
a "gate to s-trigger" circuit like this one:
http://www.doepfer.de/faq/gen_faq.htm
which allowed me to use positive-going gates to trigger the voices.  Works
great. I connected the collectors of the transistors  to the trigger lines
into the voice board (I connected them to the former ribbon cable
location).  I then connected the emmiters to ground as shown in the
schematic.  

One thing to remember:  I disconnected the sequencer from the voice board
in my DR-110, and created a sound module out of the voice board.  If you're
still planning on using the sequencer, then you'll need to add some diodes
to protect the CPU.  I don't think it would like having it's outputs
shorted to ground by the transistor :)


 Neither on the first tranniez of the voices,
>nor on the drum pad buttons. I decided to try using the trigger
>generator as control signal to a 4016 CMOS switch, and connect the
>switch channels to the traces on the drum pad switches. 

This probably should work... I originally put the transitor across the drum
pad buttons and it worked fine. Perhaps you just had something connected
wrong?  Or maybe your gates to the 4016 weren't a high enough voltage?
Excuse me if these seem like dumb questions, but it's just a possibility.

Now I am
>confused, because according to all that I know (probably not very
>much!), the trigger 'should' cause the 4016 to close the switch, and
>the traces on the DR110 'should' then be closed, not unlike when I
>press the button on the panel. No such luck though. I am obviously
>confused about how this actually works. Anybody out there ever use CMOS
>switches to trigger push-button functions on gear? I'd be psyched to
>hear if there are some tricks to this which I am missing

I can't see a reason why it wouldn't work...  but I know it works if you
use the gate-to-trigger circuit.

Dave


Resonant Frequency:
resfreq at hoohahrecords.com
http://www.hoohahrecords.com/resfreq/index.html
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