[sdiy] DR110 repaired, possible trigger ins?

[Dave Magnuson]

At 04:55 PM 5/3/04 -0700, Metrophage wrote:
>

>I noticed that the timing of the pulses from the CPU are set in certain
>ways. Especially the handclap, which is fired with three pulses. Do you
>notice any particular difference in playin the drum sounds directly,
>versus via the CPU? I thought I'd need to install both the CPU board
>and the voicing boards in the 707, which would obviously be twice as
>much work. If I don't need to, I won't.

Well, I have an unusual setup here... I have a DR-110 with gate outputs for
each voice on a 9-pin D-sub cable.   I also have a DR-110 voice board that
was hacked into a sound module with gate inputs and a bunch of added
decay/pitch and volume controls.  I intend to build a breakout box that
will allow me to connect other sources, but haven't gotten that far yet.
So far I usually trigger the sounds from the other DR-110.

I have tested the voices with external gates (from a Paia MIDI2CV), and
they worked fine, but the handclap will sound a little odd without the
repeating trigger.  All of the other voices should sound normal, however.
I've seen a circuit somewhere that creates 3 or 4 repeating pulses from a
single pulse input, and this could be adjusted to do what you need.  I
think there's one in Thomas Henry's "Electronic Drum Cookbook".  The gate
length is also important, and it's listed in the DR-110 schematic... it was
maybe 1ms or 2ms (But I don't have them in front of me, so you should check)


>Just putting a transistor directly ony the switch pad is far simpler
>than what i was trying to do! Put a 5v trigger through the third leg
>and it should go off? I look forward to trying it tomorrow morning!

In this case you're using the transistor as a switch, so it connects to the
two pads of the switch.  Make sure you get the transistor oriented properly
(so that the emitter goes to ground).  Also, don't forget the series
resistor into the base.  It would be a good idea to add protection diodes
(one to V+ and one to gnd) between the series resitor and the transistor's
base. 


>Did you send an attatchment with your post? All I got was a few lines
>of text, explaining that the attatchment was "virus free".

Sorry about that... I didn't realize my virus software was sending
attachments.  I changed the setting, so hopefully it will be less annoying
now :)    

Dave Magnuson

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