Hermite Sync Delay

A tempo-synced stereo delay whose time locks to a musical division of your clock. Its trick is click-free retiming: when you change the division or the tempo shifts, the delay crossfades smoothly to the new tap instead of glitching — so you can sweep delay times live without the usual pitch-warble and pops.

How it works

Patch a clock and the delay measures the interval between pulses to find your quarter-note. The Div knob multiplies that against a musical fraction, so the echoes always sit in the groove. Fractional delay times are read with 4-point Hermite interpolation for a clean tap, and whenever the target time moves it crossfades from the old position to the new one over a window you dial in with Smear (about 30 ms by default). Left and right run as independent channels sharing the same timing, so any stereo width in your source is preserved through the repeats.

Controls

  • Div — the delay time as a division of the measured beat, stepped through twelve values from 1/1 down to 1/64 (the . entries are dotted). Modulate it for tempo-locked tap jumps that crossfade rather than click.
  • Fbk — feedback, how much of each echo feeds the next. It tops out below unity, so it builds long tails without runaway.
  • Mix — blends from the dry signal alone up to dry plus full delay; at 100% you hear the complete wet tail.
  • Smear — how long the retiming crossfade lasts, from a near-instant snap up to 80 ms of overlap (default around 30 ms). Keep it short for tight, snappy tap jumps; open it up and the old and new delay times bleed into each other as the time moves, smearing the switch into a blur.
  • Clock — where the tempo comes from. Ext measures the pulses arriving at the clock input, which is how this module has always worked. Song follows the timeline's tempo directly, with no cable at all. Int runs at its own speed, set by the BPM field beside it. One thing worth knowing: in Ext the divisions are relative to whatever you clock it with, so feeding it sixteenths makes every label four times faster than it reads. In Int and Song the module knows what a quarter note is, so the labels mean exactly what they say.
  • BPM — the tempo for Int. In Song it greys out and shows you the timeline's tempo instead; in Ext it greys out too, because the cable is in charge.

Inputs & outputs

  • inL / inR — the stereo signal to delay; patch one side for mono.
  • clock — a pulse train sets the tempo while the Clock control is set to Ext. Unpatched, the delay sits at 120 BPM.
  • Div / Fbk / Mix / Smear CV — voltage control over each knob, summed on top of where you've set it; patch an LFO or envelope to sweep the division, feedback, wet/dry blend or crossfade time hands-free.
  • outL / outR — the processed stereo output.

Tips

  • Sequence or sweep divcv for stutter-and-settle fills — every jump retimes cleanly, so fast division changes sound deliberate, not broken.
  • Feed the same clock here that drives your sequencer and the repeats lock to the pattern automatically.
  • High Fbk with a slowly drifting Div turns a simple loop into an evolving, smeared cloud.
  • Pair fast Div jumps with a long Smear and the retimes melt into pitch-bent glides; pull Smear down for crisp, percussive snaps instead.