Oscillators — RUB Docs

RUB has two oscillators that share one voice. Wave picks the shape; Tune sets relative pitch. Mix and ×2 stay visible in both views. Open Tune with the TUNE control on the oscillator card (or the Tune tab on the homepage tour); Close returns to Wave.

Osc 1 (one cycle) and Osc 2 (two cycles) crossfade into the orange mix

TUNE button — TUNE — opens Tune A/B, Range, and sync. Same as the Tune tab on the site tour.

For the Pattern / Param sequencer axis, see Panel overview.

Wave view

Control	What it does
Osc 1 / Osc 2	Waveform pickers (`osc1_type` / `osc2_type`)
×2	Octave up per oscillator (`osc1_x2` / `osc2_x2`)
Mix	Balance between Osc 1 and Osc 2 (`osc_mix`)
Visualizer	Live mix before Rub / filter

Waveforms

Each osc chooses one of nine kinds:

Kind	Notes
Sine, Triangle, Saw, Double Saw	Classic analog shapes
Square, Pulse 25%, Saw+Square	Harder edges
Noise	Unpitched; good for percussion hits
Custom	Per-osc drawn single-cycle table — see below

Custom waveforms

Each oscillator has its own 256-point table (−1…+1), one cycle. Selecting Custom on Osc 1 or Osc 2 replaces the live visualizer with the draw well for that osc. Only one editor is open at a time — if both are Custom, Osc 1’s table is the one you edit. The other oscillator is drawn faintly behind your stroke so you can shape against it.

Gesture	Effect
Drag	Paint the cycle (gaps between mouse events are interpolated)
Shift-drag	Smooth around the cursor
Right-click	Preset menu

Right-click presets:

Item	Result
Sine / Triangle / Saw / Square	Fill the table with that shape
Smooth	Three-point smooth over the whole cycle
Reset (flat)	Silence at the centre line

Edits apply live on every stroke. An all-silent stored table is treated as an empty well and opens as a sine so you have something to hear and reshape. Leaving Custom for another wave kind keeps the drawn table; switching back restores it.

Storage. Tables live in the song as osc1_custom / osc2_custom (256 floats). They save with User / Imported presets and round-trip through Song JSON. Default sine tables are omitted from JSON to keep files small — only non-default drawings are written. Param Seq can flip osc1_type / osc2_type to Custom per step; the table itself is still the song’s stored drawing, not a per-step shape.

Playback. The engine rebuilds a mip chain from your 256 points (anti-aliased at high pitches) and reads the cycle with linear interpolation, so the same drawing stays clean across the keyboard and ×2.

×2 and Mix

Mix — equal-power balance between Osc 1 and Osc 2.

×2 doubles that oscillator’s rate (one octave up). When rates differ (×2 or relative Tune), Osc 2 is no longer phase-locked to Osc 1.
Mix is equal-power: center stays loud. 0 is Osc 1 only; full scale is Osc 2 only. Laneable.

Tune view

Press TUNE to swap the waveform knobs for pitch controls. Mix, ×2, and the visualizer stay put.

Tune A — OSC A pitch offset (−1…+1 of Tune Range).

Tune B — OSC B pitch offset (−1…+1 of Tune Range).

Range — throw in semitones (±1…±24 st) for both Tune knobs.

Control	`id_str`	Range	Role
Tune A	`tune_a`	−1…+1	Osc 1 pitch offset
Tune B	`tune_b`	−1…+1	Osc 2 pitch offset
Range	`tune_range`	1…24 st	Semitone throw for both knobs
A→B	`sync_a_to_b`	on/off	Sounding B follows stored Tune A
B→A	`sync_b_to_a`	on/off	Sounding A follows stored Tune B

How offset works

Tune A/B are normalized against Range. At Range = 12 st, Tune A = +1 is +12 semitones; at Range = 1 st the same knob is ±1 st. The value readout shows cents / semitones from the current Range. Clickable snap pips on the knobs follow the active Range.

Use a small Range for subtle beating; open it for fifths, octaves, or wide stack intervals. Param Seq can automate Tune and Range like any other laneable param — see Param sequencer.

Sync A→B / B→A

A→B sync — A→B — sounding Osc 2 follows Tune A; stored Tune B unchanged.

B→A sync — B→A — sounding Osc 1 follows Tune B; stored Tune A unchanged.

Sync LEDs make one oscillator sound the other’s stored offset without overwriting the stored knob:

A→B on — Osc 2’s sounding pitch uses Tune A; Tune B stays as stored (you can still edit and automate it for later).
B→A on — Osc 1 sounds Tune B; Tune A is preserved.

Both can be on at once (each osc listens to the other). Sync is MIDI-learnable and laneable — useful for locking a detuned pair, then flipping which offset leads mid-pattern.

Signal path notes

Osc mix sits under the amp / filter envelope before the Rub path (Straight BLEP or Rub filter + drive).
Relative Tune or ×2 unlocks independent phase; same rate + same sounding Tune keeps Osc 2 locked to Osc 1.
Full id_str list: Parameters. MIDI learn: MIDI map.