Behringer 961 Interface

Behringer 961

Introduction In August 2020 I bought a set of Behringer System 55 modules, as my first journey into Moog modular. My plan is to recreate the Klaus Schulze Moog IIIP synthesizer and Dual Sequencer setup that Klaus bought on 22nd December 1975, and used successfully for many years.

Rather than rack up a set of Behringer modules and ride away making music, I thought it would be useful to explain how the modules work, how to calibrate them, and how I have set them up and augmented them. I will also check their specifications, to see if they replicate the originals accurately and so I can understand them better.

961 Interface The original Moog and Behringer clone uses S-triggers to activate the enevlope generators and to control additional modules. The 960 Sequence Controller is V-trigger based and therefore needs a way to drive the S-trigger modules, hence the creation of the 961 Interface module. There are four independent circuits;

  • ¬†Audio-In to V-trigger Out
  • S-trigger In to V-Trigger Out
  • Two V-trigger In to S-trigger Out

All the interface circuits may be used simultaneously, in combination, or separately.

The Audio to V-trigger circuit generates V-triggers when the audio input level rises above the threshold set on the Sensitivity potentiometer. This V-trigger sensitivity varies with the frequency band of the audio signal and with the frequency of its amplitude peaks. V-trigger duration is commensurate with the length of time the audio signal remains above the sensitivity threshold.

The S-trigger to V-trigger circuits converts any short-to-ground trigger input to a V-trigger output.

Each V-trigger In to S-trigger Out circuit has two columns of six jacks each for input triggers and one S-trigger output. Column A of the V-trigger inputs will convert V-trigger signals to S-triggers with duration equal to the input. Column B determines S-trigger duration by the Switch-on-time knob ONLY. B Column S-triggers will block, extend or fore-shorten Column B V-trigger inputs to conform to whatever duration is indicated on the B-column potentiometer. A minimum switch-on-time of 40 milliseconds and maximum time of 4 seconds duration is available. Simultaneous inputs to both A and B columns may be made. Simultaneous inputs to two parallel jacks will result in the longer of the two trigger signals being accepted.

Setup The Behringer 961 replicates the original and has no need for alignment or calibration, the user manual is here 961 Quick Start Manual. It drops straight into the rack and does its primary job of converting 960 outputs into the 911 ADSR and other S-trigger inputs. The additional audio to V-trigger has lots of creative uses, and the you can get the delayed S-triggers back out to your Euro Rack system.

A quick check of the delays times show they vary from

Summary A utility modules that has hidden depths and is an accurate replica. Is it worth getting one, even though its takes up 21HP of rack sapce? If you have a 960 then its a must, and even though its simple to make or buy a V-trigger to S-trigger cable, the trigger delays are really useful without the 960. I have two in my Schulze Modular.

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