Emerson's Moog.

[Debby and Gene Stopp]

Hey I can answer this one. I worked on them for months! That was back before
the Black Moon tour in '92. Back before I got married and had kids. No more
tour busses for me - I guess that's all for the better anyway, being a
roadie is bad for the liver :)

Anyway there were at least two different programmers - the early ones and
the later ones. The early ones looked like big cards in some kind of card
cage (I've only seen pictures). The later ones are the ones that I worked
on. The later ones were built into Moog single-width modules so that they
fit into the cabinet along with the rest of the modules.

There's an old old post I sent to the AH mail list a couple years ago
describing them - I 'm not sure if I can find that file anymore. Different
hard disk, different company, all lost in the past.

Anyway they had two programmers per module, with big lighted colored
pushbuttons on the front and little slide pots on the sides of the module.
You had to slide them out to tweak them. If you pushed one of the
pusbuttons, it would light up, and all the rest would be dark. Some kind of
exclusive latching thing done with transistor flip-flops. There were eight
of these modules, all tied together electronically in the back. We never
were able to fix one of them, so we just used seven for the '92 tour.

Also on the front were six trimpots with locknuts, for tuning the 3 main
audio VCO's (three trimpots per lighted pushbutton).

The slidepots on the sides of the programmer modules controlled the
following:

Console mixer 1 volume channels 1,2,3,4 (under the VCO's)
Console mixer 2 volume channels 1,2,3,4 (on the next panel over)
VCF Freq.
VCF Resonance
VCF Mod Depth (voltage controlled reversible attenuator)
EG 1 A,D,S,R
EG 2 A,D,S,R

I think that's it.

The programmers produced voltages. The VCF freq. was easy, since that's
already a CV on the Moog. Same for the S on the envelopes. The attenuator
for the VCF mod was a little circuit on a vectorboard on the back of the CV
routing panel below the 904A VCF. The mixer and VCF resonance parameters
were controlled by Vac-Tecs soldered onto the existing circuit components.
As you may know a Vac-Tec is an LDR, so the voltages from the programmer set
the resistances of the Vac-Tecs.

Originally the EG times were controlled by phototransistors with LED's stuck
to them with silicon glue, and hidden in a metal box to keep the light out.
This sucked. It may have worked at one time, but when we got it the thing
was in sad shape. We said "screw this" and nuked it and soldered more
Vac-Tecs to the EG panel pots.

I was in synth DIY heaven at the time, and after it was all over I really
wanted to do something similar, so I did. I had a minimoog brain (just the
head, no wood case or keyboard) that I had bought out of the recycler for a
hundred bucks or something, so I decided to make it programmable. I got a
bunch of Vac-Tecs for myself (we had lots of spares for the Emerson project)
and duded up my minimoog. I mounted it in a cabinet and mounted the
programmer below it. The programmer consists of eight rows of twelve
miniature pots, so it looks like some kind of mixer. Each row is a program,
selected by a one-of-eight selector circuit using a pushbutton for each row
plus an LED to show which one's selected.

Come to think of it, I did end up with one f*cking cool machine. The VCO
board is the latest one, so it's dead accurate and always in tune.

- Gene

-----Original Message-----
From: SYNTHGUY40 at aol.com <SYNTHGUY40 at aol.com>
To: synth-diy at mailhost.bpa.nl <synth-diy at mailhost.bpa.nl>
Date: Tuesday, July 13, 1999 7:27 AM
Subject: Emerson's Moog.


>Is anyone familiar with how Bob Moog came up with the pre-programming
>switches on Keith Emerson's Modular Moog? How was this accomplished and
what
>types of circuitry did it involve?
>
>Also, does anyopne have any patch diagrams for Paia Modulars?
>Lew
>