Oscillator sync

Oscillator sync is one of the fastest ways to a bright, screaming, sweepable tone. It restarts one oscillator’s cycle against another’s, and the reset edge carves a moving comb of formants into the sound — the classic sync lead of the 1980s, and still a go-to for aggressive, cutting patches.

Aconite gives sync its own SYNC tab and makes it a full feature: the osc-to-osc routing you’d expect, plus a single-oscillator sync mode that needs no second oscillator, a dial-able and modulatable Amount, a Hard/Soft mode, and a Reset Phase target. Everything defaults to off, so a patch pays nothing until you turn sync on.

What hard sync is

A master oscillator and a slave oscillator run at different frequencies. Every time the master finishes a cycle, it forces the slave to restart its own cycle part-way through. Because the perceived pitch follows the master’s period while the slave’s (usually higher, detuned) frequency decides where the chop lands, you get a rich, formant-shifting timbre that sweeps as you detune the slave. That sweep is the sound of hard sync.

Soft sync is a gentler version: instead of resetting on every master cycle, it only resets when the slave is in the back half of its own cycle at that moment. The reset fires less often, so the snap is rounded off — the same idea, softened.

Finding the controls: the SYNC tab

All sync controls live on the SYNC tab of the source-shaping deck — the deck reads Waveshaper | Resonator | SYNC. Click SYNC and you get:

• A live sync-waveform view driven by the real oscillator — turn a control and the trace re-draws so you can see the sync edge move.
• The Routing selector, and the Ratio, Amount and Reset φ knobs, and the Hard / Soft toggle.

The SYNC tab is the only place to set the sync routing; there is no duplicate control in the oscillator strip. The panel reads your oscillator selections and greys out routings that would not produce sync — so if Osc 1 is set to FM (which cannot sync), the panel shows a note rather than leaving an option that silently does nothing. Hover any of the four main controls for a description of what it does.

When you load a preset that uses sync, the deck opens the SYNC tab for you automatically, so you land on the controls the patch is actually using.

Routing: sync between the three oscillators

The Sync Routing selector mirrors the FM routing, so the oscillator section reads one way. Osc 1 is always the slave (the one whose cycle resets); Osc 2 and Osc 3 are the masters:

Routing	What it does
Off	No sync. Oscillators run freely.
2 → 1	Osc 2 resets Osc 1 on each of its cycles. Classic two-oscillator sync.
3 → 2 → 1	Osc 3 resets Osc 2, which resets Osc 1 — a sync chain.
2 → 1 ← 3	Both Osc 2 and Osc 3 independently reset Osc 1.

To make the sweep, detune Osc 1 (the slave) away from the master with its Coarse and Detune, while the master holds the played pitch. Set it sharp and every note gets the same synced bite; sweep it with an envelope or LFO for the classic “rising sync scream.”

The Osc 1 Coarse modulation destination covers a full three octaves of range at maximum depth, so a single envelope route can drive the whole sweep in one shot — no need to combine Coarse and Detune destinations. The factory preset Prophet Sync Lead uses exactly this: an Env 3 → Osc 1 Coarse route attacks from a bright, biting sync timbre and sweeps the full range as the envelope falls.

Sync Ratio: sync from one oscillator, no second one spent

Here’s the part worth knowing. Normally sync costs you an oscillator — you have to give up Osc 2 or Osc 3 to be the master. Sync Ratio removes that cost. Turn the Ratio knob (1 to 8) and the oscillator syncs against a built-in internal master instead: the oscillator you hear runs at its pitch times the ratio, while a hidden master runs at the played pitch and fires the reset. The pitch you hear stays put; the ratio brightens and sweeps the tone, exactly like a detuned-slave sync sweep — but without spending a second oscillator.

So the fast workflow is:

1. Pick any oscillator and a sync-capable model (any of the six below).
2. Leave the other two oscillators doing whatever you like.
3. Open the SYNC tab and turn Ratio up.

That’s a full sync sound out of one oscillator. Ratio applies to all three oscillators, and it’s independent of the Routing selector — you can run osc-to-osc routing and per-oscillator Ratio at the same time.

Tip

Route an envelope or LFO to Sync Ratio from the modulation matrix and the sync sweep animates on its own — a fast attack/slow decay envelope gives you the rising-sync-scream attack from a single oscillator, no detuning and no second oscillator required.

Amount: how deep the sync bites

Amount sets how far the slave resets on each master cycle. At the top (its default) it’s a full reset — the classic, hardest hard sync. Turn it down and the slave only moves part-way toward the reset each time, softening the sync edge continuously; at the bottom there’s effectively no reset at all. Amount is a modulation destination (Sync Amt), so you can open and close the sync depth over a note with an envelope, LFO, or sequencer for animated sweeps. The edge stays clean at any Amount.

Hard vs Soft

The Hard / Soft toggle picks the two flavours described above: Hard resets on every master cycle (the brightest, most aggressive sync), Soft only resets in the back half of the slave’s cycle for a rounder, less brutal tone. Try Soft when Hard sync feels too harsh for the part.

Reset Phase

Reset φ (Reset Phase) sets where in its cycle the slave snaps to, instead of always snapping to the start. Nudging it moves where the reset seats and changes the harmonic colour of the sync edge — a subtle voicing control on top of Amount. It’s a modulation destination too (Sync Phase), so the target can move under an LFO or envelope.

Which oscillators can sync

Sync needs an oscillator with a running cycle to reset, so it works on the six phase-based models:

• Standard, Analog, SuperSaw (the whole ensemble resets together), DCO, Wavetable (a full sync source and target), and Chip — both the NES 2A03 (its pulse and triangle voices; the noise voice has no pitch to sync) and the C64 SID.

The struck and additive models — String, Modal, Kick, Additive, Acoustic, and FM — don’t sync, by their nature: they’re plucked, struck, or built from summed partials rather than run from a single cycle, so the sync controls simply have no effect on them.

Modulating sync

Three sync controls are modulation destinations in the modulation matrix, so you can animate them:

• Sync Amt — the sync depth.
• Sync Phase — the reset target.
• Sync Ratio — the single-oscillator sync sweep.

Right-click the Ratio knob to modulate it directly and watch its live mod ring.

Note

Sync is off by default, and a patch that never touches it sounds exactly as it did before — so you can add it to any existing sound without changing what’s already there.