MOTM

I've been reading through Allen Strange's book "electronic music...."
Two modules he mentioned that caught my attention were:

1. Trigger Delay
2. Control Voltage Processor

The trigger delay Is something I've found myself wanting for a while,
and the control voltage processor is a great utility module for inverting
voltages, etc...
Have any other MOTM'ers ever had any thoughts about these? Anyone ever
put together their own trigger delay?

Thanks,
John

I just designed a 1U module for my MOTM system that combines a "control
voltage processor" of sorts and a comparator. It has a DC mixer with 2
pot-attenuated inputs, plus a separate comparator. Unique about this module
is the third pot which can be used either for DC bias on the mixer or for
setting the comparison voltage. A switch selects whether the bias pot goes
to the mixer or to the comparator. (If the bias pot is on the mixer, the
comparator switches at zero-crossing. Perfect for getting a square wave
from a MOTM-380 Quad LFO. Flip the bias switch to the comparator and you
have manual control over the pulse width.) There is also an inverter
output, switch selectable to be the inversion of the mix output or of the
comparator output. There are many sorts of control voltage processing
(clipping, full wave rectifying, etc.), but attenuate, mix, invert and
offset are the basic ones. The mixer output is normalled into the
comparator input. (Three inputs, three outputs, three pots, two switches.)
It will use a Schaeffer panel and a Stooge bracket.

I am building two of these, even though I only have room left for 1U in my
26U Synthesizers.com cabinet. Guess one will have to go into the next
cabinet (the one with the 3-voltage power supply and the MOTM 500 series
modules).

I have also just ordered the entire Electronotes package ($265) from Bernie
Hutchins. Looks like I will be designing more modules and panels. This
could get addictive.

A trigger delay could be a very simple module with one input and one output,
with a manual delay control. Or it could be made fancy and have a
voltage-controlled delay (yes!). Now you've got me thinking.

-Richard

----- Original Message -----
From: "Inform3r" <inform3r@...>
To: "MOTM List" <motm@yahoogroups.com>
Sent: Thursday, October 03, 2002 7:42 PM
Subject: [motm] Trigger Delay & CVP


> I've been reading through Allen Strange's book "electronic music...."
> Two modules he mentioned that caught my attention were:
>
> 1. Trigger Delay
> 2. Control Voltage Processor
>
> The trigger delay Is something I've found myself wanting for a while,
> and the control voltage processor is a great utility module for inverting
> voltages, etc...
> Have any other MOTM'ers ever had any thoughts about these? Anyone ever
> put together their own trigger delay?
>
> Thanks,
> John
>
>

Every time this comes up, I'm obligated to say: you too can patch
your own trigger delay from available MOTM modules!

The Ingredients: two MOTM-800s and one MOTM-700.

The Patch:
One of the 800s is just being used to generate a 5V constant signal
that will be gated on or off by half of the 700. If you have another
voltage source, you don't need this 800. Set it to full sustain, with
no gate or trigger plugged in. The output will be 5V.

Plug this output into the B port of the 700. The X port will be the
delayed gate output, suitable for driving any delayed gated modules.

The second 800 will generate the delay. Plug the gate input into your
gate source output such as a keyboard or whatever. Set sustain full,
release zero, and attack to suit. The attack time will control the
delay time.

Plug this 800's output into the 700's top cv in port. Play with the
switch pot and the attack time to control the delay for A to switch
to B. Enjoy!

Moe

BTW, you DO have a 700 or two, don't you? ;>)

>>>>

I've been reading through Allen Strange's book "electronic music...."
Two modules he mentioned that caught my attention were:

1. Trigger Delay
<<<<

At 5:14 AM +0000 10/04/02, mate_stubb wrote:

>
>Plug this 800's output into the 700's top cv in port. Play with the
>switch pot and the attack time to control the delay for A to switch
>to B. Enjoy!

That's very clever :) I'm thinking the delay time could control the length
of the resulting gate as well.

How fast is the 700?? Perhaps it could handle some of the tasks
traditionally done with a comparator module. Combined with an 830 and 820,
it might satisfy much of the interest in a "Control Voltage Processor".

Of course, I still like my analogue logic idea. I put together a working
breadboard by shadowing op-amp circuits with CMOS. It looks like it might
be possible to design a more elegant circuit using LM3900 "current"
op-amps, but I haven't tried that yet. Then again, I'm thinking that might
not be accurate enough to handle VCO voltages like the mux controlled 1013
circuit.

As far as MOTM is concerned, and if I understand Paul correctly, there is a
"form factor" for the digital 500 series that makes those modules much
easier to design and produce. So in addition to making "weird" modules,
perhaps this "form factor" could be used for "meat and potatoes" modules
for control voltage logic and logic processing, and might even allow for a
little extra gravy :)

>BTW, you DO have a 700 or two, don't you? ;>)

Not yet :)

It's fast enough to be used at audio rates as a wave clipper. Run a
VCO saw into the cv input and another wave from the vco into the a or
b input, then take x as out. You can do all sorts of wave chopping by
varying the pot.

Moe

>>>>

How fast is the 700?? Perhaps it could handle some of the tasks
traditionally done with a comparator module.
<<<<

In addition to the MOTM modules suggested for doing a trigger delay, you can
also get the Encore Electronics UEG to do it. And the delay can be voltage
controlled.

Also, the MOTM-830 mixer will give you those inverted voltages you wanted from
a CVP.

-Elhardt