# Oscillators

Wave and Tune views — shapes, Custom draw, ×2, Mix, Tune A/B, Range, and sync.

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](/#instrument)); **Close** returns to Wave.

![Osc 1 (one cycle) and Osc 2 (two cycles) crossfade into the orange mix](component:osc-preview)

![TUNE button](figure:osc-tune)

For the Pattern / Param sequencer axis, see [Panel overview](/docs/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 |

![Osc 1](figure:osc1)

![Osc 2](figure:osc2)

### 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](/docs/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

![×2](figure:osc1-x2)

![Mix](figure:mix)

- **×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](figure:tune-a)

![Tune B](figure:tune-b)

![Range](figure:tune-range)

| 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](/docs/param-sequencer).

### Sync A→B / B→A

![A→B sync](figure:sync-a-b)

![B→A sync](figure:sync-b-a)

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](/docs/parameters). MIDI learn: [MIDI map](/docs/midi-learn).