Utilities

WR-961

The WR-961 Interface - trigger-format glue between S-trig and V-trig conventions.

The WR-961

The WR-961 is the trigger-format glue between two competing trigger conventions. V-trig (voltage trigger) is the active-high standard: a positive voltage pulse, idle low, active above ~2.5 V. S-trig (switch trigger, sometimes called short trigger) is the active-low convention - fires when an external switch closes a circuit to ground. The WR-961 mediates between them in four parallel sections.

The four sections are: an audio-to-V-trig envelope follower (a comparator that fires a V-trig pulse when an audio signal exceeds a SENSITIVITY threshold, useful for triggering envelopes from drums or rhythmic loops); two S-to-V converters that invert active-low S-trigs into active-high V-trigs; four V-to-S pass-through converters that mirror the duration of an incoming V-trig as an active-low S-trig; and four V-to-S fixed-time converters that emit a fixed-width S-trig pulse on each rising edge of the input, with duration set by the shared SWITCH ON TIME knob covering 40 ms to 4 s exponentially.

The audio-trigger section deserves its own mention. Patch a drum mic, a rhythmic loop, or any signal with transients into the audio input, set the SENSITIVITY threshold, and the WR-961 outputs a clean V-trig pulse on each transient. The same idea later became its own module class - envelope follower, transient detector, gate-from-audio - but here it is baked into a utility panel.

The WR-961

The WR-961 has two knobs: SENS (0.1 V to 10 V, sets the audio-to-V-trig threshold) and SWON (40 ms to 4 s exponentially, sets the column-B fixed-trigger duration shared across all four channels). Eleven inputs: one audio (AUD), two S-trigs (S1, S2), four column-A V-trigs (VA1 ... VA4, duration pass-through), and four column-B V-trigs (VB1 ... VB4, fixed-time one-shot). Eleven outputs mirror the inputs across the four conversion sections. The audio envelope follower uses a fast-attack / slow-release peak detector and a comparator at the SENSITIVITY threshold. Unpatched S-trig inputs are detected via the connected bitmask so an empty jack doesn't read as a permanent active-low trigger.

In a patch

The WR-961 is a bridge module. In a mixed-convention patch where S-trig modules sit alongside V-trig sources, the WR-961 sits between them. Patch a clock (V-trig) into a column-A V-trig input and take the column-A S-trig output to drive a WR-911 (or any S-trig envelope). Or run an S-trig keyboard's gate out into an S-to-V channel and take the V-trig out to fire a modern ADSR.

The audio-to-trigger section extracts gates from rhythmic audio. Send a kick drum or a bass voice into the audio input, set SENSITIVITY just above the rest noise, and the WR-961 puts out a V-trig that follows the actual transient instead of the clock grid - good for sidechain patches and groove-following modulation.

The fixed-time column-B converters are useful as a gate quantizer: feed any trigger of any duration into VB1 to VB4 and every output pulse comes out at exactly SWITCH ON TIME. Handy for keeping percussion tight when the source clock has irregular pulse widths.

Inputs

AUD (audio) — Audio input to the envelope-follower comparator. When envelope magnitude crosses SENSITIVITY, V/A fires.
S1 (gate) — S-trigger input 1. Active-low: when signal drops below 0.8 V, V1 goes high.
S2 (gate) — S-trigger input 2. Independent from S1.
VA1 (gate) — V-trig input, column A, channel 1. SA1 mirrors the duration inverted (active-low S-trig).
VA2 (gate) — V-trig input, column A, channel 2.
VA3 (gate) — V-trig input, column A, channel 3.
VA4 (gate) — V-trig input, column A, channel 4.
VB1 (gate) — V-trig input, column B, channel 1. On each rising edge, SB1 pulses active-low for SWITCH ON TIME.
VB2 (gate) — V-trig input, column B, channel 2. Shares SWON with all B channels.
VB3 (gate) — V-trig input, column B, channel 3.
VB4 (gate) — V-trig input, column B, channel 4.

Outputs

V/A (gate) — V-trig from audio envelope. Goes high when input envelope crosses SENSITIVITY.
V1 (gate) — V-trig from S-trig input 1.
V2 (gate) — V-trig from S-trig input 2.
SA1 (gate) — S-trig from column-A V-trig 1 (pass-through duration). Active-low.
SA2 (gate) — S-trig from column-A V-trig 2.
SA3 (gate) — S-trig from column-A V-trig 3.
SA4 (gate) — S-trig from column-A V-trig 4.
SB1 (gate) — S-trig from column-B V-trig 1 (fixed duration). Active-low.
SB2 (gate) — S-trig from column-B V-trig 2.
SB3 (gate) — S-trig from column-B V-trig 3.
SB4 (gate) — S-trig from column-B V-trig 4.

Controls

Sens — Audio-to-trigger threshold 0.1 - 10 V.
SwOn — Column-B S-trig fixed duration. 40 ms - 4 s, exponential.

Synths.pw and the Classic-series modules are not affiliated with, endorsed by, or sponsored by Moog Music Inc. Module numbers reference the late-1960s American modular tradition and are used in a historical sense.

← Back to all modules