← ZEROPOINT
Four Letter RecordsVersion 0.3

ZEROPOINT — How it works

Through-zero timecode flanger

01The rig

ZEROPOINT is a simulation of a legendary studio rig: a Lexicon PCM 42 delaying SMPTE timecode read off a Studer A827's repro head, a TimeLine Lynx synchronizer chasing that displaced code, and the tape machine physically dragged through the zero point against the DAW's dry track.

The plugin models the whole control chain — servo, capstan, tape magnetics (Jiles‑Atherton hysteresis with real AC bias), and speed-dependent head losses.

Pro Tools LTC ─▶ LYNX 1 ─▶ LYNX 2 ─▶ LYNX (Studer) ─▶ capstan ─▶ TAPE SPEED v(t) reference code ▲ │ │ delayed readbackPCM 42 │ ▲ │ code read off the REPRO head ◀─────────┘ audio ─▶ bias+hysteresis ─▶ tape ─▶ repro losses(v) ─▶ EQ ─▶ out ──┐ dry reference, delayed by L ───────────┴─▶ sum = flange
Why the delay sits in the readback Delaying what the synchronizer reads back makes it believe the tape is late, so it drives the capstan faster — and the tape ends up running ahead of the reference by the delay amount. That is what lets the offset reach and cross zero. It also places the delay inside the servo's feedback path, which is destabilising by construction: that lag is why hard gestures run away and break lock the way the hardware does.

02The sweep moves a machine

The sweep knob doesn't move a delay — it moves a machine. The servo leans, overshoots, breaks lock, runs away. Through-zero with a complete null; two-machine mode for the deep multi-machine flange of the early Queen records.

macOS · Apple Silicon + Intel AU VST3 Standalone AAX in progress 6 factory presets MANUAL sweep + MIDI Learn
Status ZEROPOINT is in development — current build v0.3.