Effects

Delay

A stereo delay with ping-pong, freeze, clock sync, and tape-style feedback coloration.

What is a Delay?

A delay is one of the oldest effects in electronic music: a recorded copy of a sound played back a moment later. Send a sound in, hear it again 100 ms (or 1 s, or 5 s) later. Add a feedback path - send some of the output back to the input - and you get repeats, each quieter than the last, until they fade. That simple structure is the basis for everything from rhythmic echoes to ambient washes to flangers and choruses.

Delay was originally acoustic (cathedrals, plate echoes), then tape (Roland RE-201, Echoplex, Binson Echorec), then analog electronic via bucket-brigade BBD chips (MN3005 and friends), then digital. Each technology added its own coloration: tape darkened repeats and added wow/flutter, BBDs introduced clock noise and a soft top-end, digital was clean by default. The best delays today let you choose how much of that coloration you want.

The single most important thing about a delay is what happens *inside the feedback loop*. A pure feedback path repeats indefinitely without changing - useful but boring. A feedback path with a lowpass filter darkens each repeat (tape behavior - high frequencies get absorbed). A feedback path with saturation warms each repeat. A feedback path with pitch shifting produces shimmer reverb. A feedback path with modulation produces chorus and flange. The delay is just plumbing; the feedback path is where personality lives.

In modular synthesis, delay is often more than an effect - it's a sound source. Patch a gate into a delay set to 25 ms and you have a comb filter; modulate the time and it becomes a flanger; patch the output back into a VCA and you have feedback loops you can play. Delay is one of the most rewarding effects to put under voltage control.

Our Delay

Our delay is a stereo 1 ms-10 s digital delay with a tape-style feedback path. The tone control is a DJ-style LP/HP crossfader placed *inside* the feedback loop - center is neutral, turn left for darker repeats (each pass loses highs, like real tape), turn right for thinner, brighter repeats. There's also tanh saturation in the feedback path, so feedback >0.7 starts warming up the way a tape echo would, instead of running away into clean infinity.

Time CV is V/Oct tracked - send a 1V change and the delay time doubles or halves musically, which means you can play melodic comb-filter pitches by sending a keyboard output to time CV. The CLK input does tap-tempo automatically: send any pulse train and the delay measures the period and matches it. Time, feedback, and tone all have CV inputs with attenuverters.

Two outputs per channel: WET (delay only, no dry signal) and MIX (dry+wet according to the mix knob). Ping-pong toggles cross-feedback between L and R for stereo bouncing; freeze captures the buffer and loops it forever. 14 HP, 8 parameters, mono-input-on-L normalled to R for one-cable mono use.

In a patch

The classic placement: end of the chain. VCO -> VCF -> VCA -> delay -> output. Use the MIX outputs for a single-cable dry+wet route to the output, or the WET outputs to keep delay isolated for sidechain processing or to send through reverb for a 'long delay into long reverb' wash.

Modular adds the fun part: every parameter is voltage-controllable. Patch an LFO into time CV for chorus and flanger effects (very short delay times modulated by a slow LFO). Patch a clock into the CLK input for tempo sync. Patch an envelope into feedback CV to swell the repeats on each note. Patch a random CV into time CV for grungy, glitchy, broken-tape effects.

For send-effect routing, set MIX to 100% wet and use the WET outputs into a separate mixer channel. Now you can balance the dry signal and the delay independently - a more flexible patching idiom borrowed from studio mixing consoles.

Inputs

IN L (audio) — Left audio input. If only IN L is patched, the signal is sent to both left and right delay lines (mono-to-stereo).
IN R (audio) — Right audio input. Patch both IN L and IN R for true stereo delay processing.
TIME CV (cv) — Voltage control over delay time. Amount is scaled by the Time attenuverter knob. Use an LFO here for chorus-like pitch wobble on the repeats.
FDBK CV (cv) — Voltage control over feedback amount. Scaled by the Feedback attenuverter. Useful for automating how many repeats you get.
TONE CV (cv) — Voltage control over the tone filter. Modulate this with an LFO or envelope for evolving delay character.
CLK (gate) — Clock sync input. The delay measures the interval between clock pulses and sets the delay time to match. Overrides the Time knob when patched.

Outputs

WET L (audio) — Left wet (delay-only) output. Contains only the delayed signal, no dry. Use when you want to process the echoes separately.
WET R (audio) — Right wet (delay-only) output. In ping-pong mode, alternating repeats appear on left and right.
MIX L (audio) — Left mixed output. Blends the dry input with the wet delay signal according to the Mix knob. Convenient for a single-cable connection to Output.
MIX R (audio) — Right mixed output. Same as MIX L but for the right channel.

Controls

Time — Delay time from 1ms to 10 seconds. Short times (under 50ms) create comb-filter/flanger effects. Medium times (100-500ms) give classic echo. Long times create ambient washes.
Feedback — How much of the delayed signal feeds back into the input (0% to 98%). Low values give a single echo. High values create many repeats that build up. At maximum the repeats sustain almost indefinitely.
Tone — LP/HP crossfader applied in the feedback path. Center (0) is neutral. Turn left for darker, warmer repeats (lowpass). Turn right for thinner, brighter repeats (highpass).
Mix — Dry/wet blend for the MIX outputs (0 = fully dry, 1 = fully wet). Only affects the MIX outputs - the WET outputs always carry 100% wet signal.
Time Atten — Attenuverter for the Time CV input (-1 to +1). Scales how much incoming CV affects delay time.
Fdbk Atten — Attenuverter for the Feedback CV input (-1 to +1). Scales how much incoming CV affects feedback.
Ping-Pong — When enabled, repeats alternate between left and right channels, bouncing back and forth across the stereo field.
Freeze — When enabled, the current delay buffer is captured and loops forever. New input is blocked. Great for creating sustained textures to play over.

Inspired by

Delay is one of the oldest effects in electronic music: a recorded copy of a sound played back a moment later. Tape echoes (Roland RE-201, Echoplex) added the magic of progressively darker, warmer repeats as tape absorbed high frequencies on each pass. We model that behavior digitally with a tone filter and tanh saturation inside the feedback path, plus modern conveniences (clock sync, ping-pong, buffer freeze) that any well-equipped Eurorack delay would offer.

Make Noise Mimeophon
Roland RE-201 Space Echo
classic Eurorack BBD delays

← Back to all modules