4ms Dual Looping Delay
Dual synchronized delay and looper with clock sync and reverse
20 HP Eurorack module
The 4ms Dual Looping Delay (DLD) is a dual-channel digital delay and looper with sample-accurate clock synchronization. Each channel offers nearly 3 minutes of delay/loop time at 48kHz/16-bit, with features including infinite hold looping, reverse playback, send/return for external feedback processing, and 1V/oct tracking for Karplus-Strong resonant delays.
Features
- Dual independent delay/loop channels
- Nearly 3 minutes per channel at 48kHz/16-bit
- Sample-accurate clock synchronization
- Infinite Hold looping mode
- Reverse playback per channel
- Send/Return per channel for external feedback processing
- 1V/oct tracking for resonant delays
- CV and trigger control for all major features
- Normaled I/O for mono, stereo, or cascade use
- Open-source firmware
Controls & Jacks (37)
- Time A — Sets delay/loop time for channel A as a division or multiplication of the clock. Ranges from 1/16th of a beat to 32x the beat. At short time
- Time B — Sets delay/loop time for channel B. Same range as Time A. When cascaded (B fed from A), creates complex rhythmic echo patterns.
- Regen A — Controls feedback amount for channel A. 0% = single repeat, 100% = infinite sustain, 110% = self-oscillation. The sweet spot for looping is
- Regen B — Controls feedback amount for channel B. Same range as Regen A. High regeneration with short times creates metallic resonant tones.
- Feed A — Cross-feed from channel B into A's feedback path. Creates cascading stereo delay patterns. At 100% the full B signal enters A's feedback loo
- Mix A — Wet/dry blend for channel A output. Full CCW = dry only, full CW = wet only, center = equal mix. Normalled to Out A jack.
- Mix B — Wet/dry blend for channel B output. Same behavior as Mix A.
- Feed B — Cross-feed from channel A into B's feedback path. Complement of Feed A for bidirectional cascading.
- Ping — Tap tempo / clock input. Sets the master beat for both channels. Accepts gates, triggers, or audio-rate signals for Karplus-Strong effects.
- Clock — External clock input. Similar to Ping but specifically for clock signals from sequencers or clock modules like the QCD.
- Loop A — Gate input to toggle looping on channel A. High gate = loop engaged (infinite hold). Captures audio and plays it back continuously.
- Loop B — Gate input to toggle looping on channel B. Same behavior as Loop A.
- 1/8 A — Trigger input that divides channel A's time by 8 while held. Creates rapid stutter/glitch effects. Release returns to normal timing.
- 1/8 B — Trigger input that divides channel B's time by 8 while held. Same behavior as 1/8 A.
- In A — Audio input for channel A. Normalled to In B — a signal patched here feeds both channels unless B has its own input.
- Return A — Returns externally processed audio back into channel A's feedback loop. Patch from Send A through effects and back here.
- Rev A — Trigger/gate input and button to toggle reverse playback on channel A. Reverses the direction of the delay buffer playback.
- Rev B — Trigger/gate input and button to toggle reverse playback on channel B.
- Return B — Returns externally processed audio back into channel B's feedback loop.
- In B — Audio input for channel B. If unpatched, receives the signal from In A (normalled connection).
- Out A — Main audio output for channel A. Carries the wet/dry mix set by the Mix A knob.
- Send A — Sends channel A's delayed signal out for external processing (e.g., filter, distortion) before it returns to the feedback loop via Return A.
- Hold A — Gate input for infinite hold on channel A. While gate is high, the current delay buffer loops infinitely. New audio can be windowed in over
- Hold B — Gate input for infinite hold on channel B. Same behavior as Hold A.
- Send B — Sends channel B's delayed signal out for external processing via Return B.
- Out B — Main audio output for channel B. Normalled from Out A — if nothing is patched into In B, Out B carries channel A's output.
- Time A CV — CV input for modulating Time A. Sweeps through time divisions smoothly. At audio rates with short delays, creates pitched resonant effects.
- Regen A CV — CV input for modulating Regen A. Useful for ducking feedback with an envelope or building feedback swells.
- Feed A CV — CV input for modulating the cross-feed amount into channel A.
- Feed B CV — CV input for modulating the cross-feed amount into channel B.
- Regen B CV — CV input for modulating Regen B.
- Time B CV — CV input for modulating Time B. Same behavior as Time A CV.
- Rev A — Trigger/gate input and button to toggle reverse playback on channel A. Reverses the direction of the delay buffer playback.
- Rev B — Trigger/gate input and button to toggle reverse playback on channel B.
- +16 A — Button to multiply channel A's delay time by 16. Toggles between normal and 16x extended time. Useful for switching between short rhythmic d
- Infinity — Button to engage infinite hold on both channels simultaneously. Captured audio loops forever. New audio can be layered on top by adjusting t
- Ping Pong — Button to toggle ping-pong mode. Audio bounces between channels A and B, creating a stereo ping-pong delay effect.
How-To Guides
- Synchronized Stereo Delay
- Live Looping Performance
- Karplus-Strong Resonant String
- Cascading Delay Chain
- Reverb-Like Dual Delay
- Pressure-Controlled Sound-on-Sound
Explore the interactive Dual Looping Delay panel on BleepDex — tap any control to learn what it does.
