Triggers & the mOOG 961 INTERFACE

.... iT'S  interesting that old Moog Modulars use both S-trigs & V trigs.

 Triggers might be produced by sequencers, the key on a keyboard, drum controllers & foot pedals.

They are useful for starting an envelope generator or advancing a sequencer.

A S-trig is just a passive switch closure to ground.The voltage starts high, and when the trigger occurs the voltage shorts to ground. It's also known as a switch trigger or shorting trigger.

Moog Keyboards produce S-trigs. 

Moog 911 Envelope Generators need S-triggers to start their cycle.

In comparison,  V-triggers start at zero volts and rise to a standard level .. usually 3V.

The 911 plugs into the Moog modular using a 22 pin PCB/edge card connector.

It's a ADSR envelope generator.

The pin out is as follows:

1. +12V

2. GND

3. -6V

14. Trigger out
21. to Trigger switch (Jones S-302)

The Moog manual suggests a regulated AC supply, such as a Moog Model 901 or dry batteries.

Max current is 50 milliamperes.

Range of T1: 10 ms to 10 secs (attack)

Range of T2: 10 ms to 10 secs (delay)

Range of T3: 10 ms to 10 secs (Release)

Range of  Esus:  0 to Emax

Esus = sustain.

Emax = voltage at which T2 begins. = 5.5V +/- 10% 

You trigger the 911 by closing a switch. So unlike most EG's you will encounter today, no voltage is supplied to trigger the module ... its quite the opposite.

The 960 sequencer produces V-triggers.

V-triggers start at zero volts and rise to a standard level .. usually 3V.

In the Moog Modular world, the S-trigger uses a special  2 blade Cinch Jones connector.

The V-trig uses the standard 1/4 inch jack. 

 So how do you get a trigger from the 960 sequencer to start a envelope cycle of a 911 EG.

To convert triggers from one to another, you can use a special conversion cable or the 961 interface

There are 2 types of this module..... the P (portable) and the C (console).
The above module is the P-type ... used for portable systems.

This is a audio to V-trig converter.
Plug in any audio source (like an old drum machine) into the jack on the left.
It will be transformed into a voltage trigger.

The control is a sensitivity knob.
The console version has this section right at the top of the module.

This is the V-trig to S-trig converter.
My module, has been modified somewhat, so may look a bit confusing. However, the V-trigs (from your 960 sequencer) enter into the jacks on the left, and S-trigs exit via the dual blade Cinch J plug.

There are 2 input sections: A & B
Any inputs into column A will have the same duration as the outputs
The Column B in jacks are connected to a Switch-On Time knob.

This allows you to control how short or long the “ON” duration is for S-Trig signals. (40ms to 4 seconds). You can use this to trigger the 911 envelope generator. 

                                                                                                                                                                                                                                             

                                                                                                                                                                                                                                

  Links        

+ Modular Synthesis                 

     
+ Here are the Mouser links for the Moog connector hardware:
https://www.mouser.com/ProductDetail/571-5-530501-5
https://www.mouser.com/ProductDetail/571-582388-9
 

Moog models using the S-Trigger system

• Moog Modular System 15
• Moog Modular System 35
• Moog Modular System 55
• Moog Modular System 3C
• Minimoog Model D
• Moog Sonic 6
• MicroMoog
• Moog Liberation
• Moog Source
• Moog Taurus
• Moog Prodigy
• Moog Rogue
• Moog Sattelite
• MinitMoog
• Moog Ribbon Controller
• Moog Sample & Hold Controller
• Moog Drum
• Moog 1130 Drum Controller
• Moog Modular Keyboards 
• Moog Mother 32 ??