[sdiy] DR110 repaired, possible trigger ins?

[Metrophage]

I missed my first drum machine, a DR110 which was given to me about
1990- before I even cared about programming percussion. 

Recently, I bought a DR110 off of a guy for cheep. Good thing it was
cheep, as it was borken! First, the infamously handy LCD was subtley
cracked on the corner, resulting in some drum steps never being
visible. More troubling was that the hats and cymbals did not work! My
nearly useless meter showed that there did appear to be signals
eminating from the digital noise ics, so i figured since >all< brass
was defunct, that between the filter and the main synth transistors.
Sure enough, even though I had visually inspected, an electrolytic cap
had lifted its pad. A little scraping and fine wire have resolved this
problem! Unfortunately, the whole LCD has fallen off. Oh well.

Since the graphic is gone, 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. 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. 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.

Now, this is a little crazy... but what I want to do is install the
DR110 boards under the pcbs of my TR707! It is easy to get triggers
from each main voice of the 707, where the envelopes are generated.
What I really want to do, if I can trigger them, is to make each main
voice of the 707 trigger sounds from the DR110 boards, which will then
be routed through the 707 outs. Not exactly a quick and easy task, but
how many easy to edit, MIDIified analog drum machines are there out
there? And isn't this thing supposedly "Transistor Rhythm" anyway?
What's more, the 707 case has enough room for the mods I want to do to
the DR110 sounds, which don't fit in the DR110 case.

I just got Lancasters CMOS Cookbook, so I guess I'll check there this
morning.
CJ


	
		
__________________________________
Do you Yahoo!?
Win a $20,000 Career Makeover at Yahoo! HotJobs  
http://hotjobs.sweepstakes.yahoo.com/careermakeover