OrDrumbox v2 User Manual

1. Getting Started

OrDrumbox v2 is a browser-based drum machine and pattern sequencer. When you open the application, you see:

• Toolbar at the top — main controls
• Pattern Panel — the step sequencer grid

Basic Workflow

1. Select a Pattern from the Pattern dropdown
2. Click Start to begin playback
3. Click on the grid to add/remove notes
4. Click a track name to open the Track Editor
5. Click a note cell to open the Note Editor
6. Use Auto Gen to enable automatic pattern regeneration (toggle)

2. Toolbar

The toolbar is the fixed control bar at the top of the screen.

Controls

3. Pattern Panel

The Pattern Panel displays all tracks as horizontal step grids below the toolbar.

Display

• Pattern name (red), BPM, beat count, and track count are shown in the header.
• Each track row shows: track name + step grid.
• Playhead — vertical line moving across the grid during playback.
• Waveform overlay — real-time waveform display over the grid (toggle with V key).
• VU meters — real-time level bars on each track row.

Header Action Buttons

Per-Track Controls

Bottom Row

Cell Colors

Interactions

Editing a note's velocity & pitch

A note can be tuned straight from the grid, without opening the Note Editor. Two gestures do the job, and they work the same way in the Piano Roll.

• Axis lock: the gesture commits to one axis after 3 px of movement, so a sloppy diagonal never changes both velocity and pitch at once.
• Chords: in a cell holding several notes, the slice under the pointer is the note edited — one voice per slice.
• Audible: the note is re-played as it changes (a few times per second at most), so an edit is never silent.
• Safe: a drag never deletes the note — the click the browser sends at the end of the gesture is swallowed. A plain click still selects the note, and a second plain click still deletes it.
• Undo: a whole drag (or a held key) is one history step — Ctrl/Cmd + Z restores the original value in one go.

Shift + Arrow has two meanings in the grid. It edits the note only when that note was picked with the mouse (a click or a drag); when the note was merely reached by walking the cursor with the arrows, Shift + Arrow keeps extending the multi-step selection used for a range delete. A plain arrow always hands Shift + Arrow back to range selection.

Editing gauge

While a velocity or pitch is being edited, a gauge pops up over the note:

• a knob-style arc that fills with the value — velocity directly (0.8 fills 80 % of the sweep), and for pitch the place the note occupies on the keyboard, so the arc moves as you transpose;
• the note name and its MIDI number, then the new value with a ▴ / ▾ arrow;
• a coloured ring around the edited cell.

The gauge stays up while you drag or hold the key, then fades out about 700 ms after the last change. The note's own tooltip is hidden while the gauge is displayed, so the two never overlap, and comes back afterwards. The pattern grid has no pitch axis, so this gauge is the only place a transposed note can be read.

4. Track Editor

The Track Editor opens when you click a track name. It contains all track-level parameters organized in groups.

Basic / Transport

Variation

The Variation slider (0–100%) controls the intensity of automatic beat randomization applied on each loop iteration. At 0%, the pattern plays as-is. As you increase the value, the sequencer randomly adds anticipation notes, doubles, ghost notes, silences, and tweaks velocity or pitch — making the beat evolve over time without manual editing. Each loop gets a fresh set of variations, so the pattern never repeats exactly the same way.

Levels / Pitch

All four parameters support LFO modulation (click the row to open LFO settings).

Filters

The Freq and Q parameters support LFO modulation.

Effects

Each effect has an LED toggle (green = active). Tabs 1/2/3 are on the same line as the "Effects" title.

Reverb

Reverb Presets:

• room — Small room (0.8s decay)
• hall — Large hall (2.4s decay)
• plate — Plate reverb (1.6s decay)
• spring — Spring with ripple (1.2s decay)
• gated — Gated reverb (0.7s, cuts off at 65%)

Delay

Delay Types:

• slap — Single echo, short feedback
• tape — Tape delay with filter, warm feedback
• pingpong — Stereo ping-pong between left and right

Saturation (Sat)

Saturation Types:

• soft — Smooth tanh-based clipping
• hard — Hard clipping
• tape — Analog tape warmth

LFO Sub-Panel

Click any LFO-capable row (Velo, Pan, Pitch, Freq, Q) to open the LFO editor.

Sound Sub-Panel

Loop / Pattern Sub-Panel

5. Note Editor

The Note Editor opens when you click a note in the Pattern Panel. It shows per-note parameters.

Header

• Track name, position (beat X step Y), and close button.

Vel / Pitch / Pan

Velocity and pitch can also be edited directly in the grid: drag a note up/down or left/right, or use Shift + ↑/↓ and Shift + ←/→ on a note picked with the mouse (see Pattern Panel → Editing a note's velocity & pitch).

Triggers

How triggers work:

A note triggers when: (currentLoop + pos) % every === 0

Retrig

Euclidean fill: Adds N evenly-spaced notes between this note and the next note in the track, creating complex rhythmic patterns.

Retrig Prob: This probability controls whether retrig sub-hits, euclidean fill sub-hits, and arp sub-notes are actually played. The base note (first hit) is always played.

Arpeggiator

How arpeggiator works:

• When Range > 0, generates pitch offsets from the selected scale
• Arp sub-notes use the Retrig Prob probability

6. Tools Panel

The Tools Panel opens when clicking the "Tools" button in the toolbar. It has three tabs: Pattern, Export, and Import.

Pattern Tab

Export Tab

Exports apply to the selected pattern. Filenames: ordrumbox-{patternName}.{ext}

Which tracks are exported: the same rule as playback — if at least one track is soloed, only the soloed tracks are exported, otherwise every track that is not muted.

MIDI Export details:

• Standard MIDI File, Type 1, resolution 96 PPQN (1 engine tick = 3 MIDI ticks)
• Track 0 (conductor): track name orDrumbox Pattern, 4/4 time signature and the tempo of the pattern
• Track 1+: one MIDI track per exported track, named after the track (a track without notes is omitted)
• Drum instruments → MIDI channel 10; melodic instruments get their own channel plus a Program Change
• Base note = the instrument's GM key, otherwise C3 (48); melodic samples with a root note use it as base. Pitch = track pitch + note pitch (+ pitch LFO)
• Velocity (0–127) is the note velocity × 127; a velocity LFO replaces it
• Every note is written as a fixed 16th-note (24 MIDI ticks) note on/off pair
• Not exported: pan, filter LFOs and other parameters without a MIDI equivalent
• Loops repeats the pattern in the file (each loop offset by the pattern length)

WAV Export details:

• Rendered offline (OfflineAudioContext) with the same engine and mixer as playback, including track effects
• Format: 16-bit PCM, stereo, 44.1 kHz
• Length = beats × 60 / BPM × loops (8 beats at 120 BPM = 4 s per loop)
• The button label changes to Exporting... until the file download starts
• The sounds of the exported tracks must be loaded — samples belonging to another drumkit are loaded on demand (see Track Editor → Sound)

Import Tab

7. Output Panel

The Output Panel opens when clicking the "Output" button in the toolbar. It provides master mixing controls and a real-time spectrum analyzer.

Master

The Volume tab features a rotary knob for master output volume, displayed above the real-time spectrum analyzer.

Filters (Master)

The filters section is part of the master bus signal chain, applied after the compressor.

Compressor

The compressor section uses a VST-style rotary knob layout with a power button toggle. The signal chain is: Pre-Gain → Compressor → Low-cut → High-cut → Master Gain.

The power button (⚡ icon, top-right) toggles the compressor on/off. Green glow = active, dimmed = bypassed.

Knob interaction: Vertical drag to change value. Arrow keys for precision (±step). Shift+drag or Shift+arrows for fine mode (±0.1 step). Double-click to reset to default. Right-click opens a numeric input to type an exact value (clamped to min/max and snapped to step). The same applies to the sliders (Loops, BPM, pattern settings).

Spectrum Analyzer

A real-time frequency spectrum display updated via requestAnimationFrame. Beats are colored from dark (low amplitude) to red (high amplitude).

8. Synth Editor

The Synth Editor is a full-screen overlay for editing soft synthesizer parameters. It opens from the Track Editor's "Edit" button when a generated sound is selected.

Header: OK (saves changes) / Cancel (reverts) buttons.

Preset Management

The footer bar provides preset management controls:

Group Controls

Each parameter group (Oscillators, Filter, LFO, etc.) has a bypass/power button (LED toggle). When dimmed, the group is bypassed and its processing is skipped.

Visual Displays

• Waveform preview — Shows the oscillator output waveform (updated in real-time when playing)
• ADSR envelope canvas — Visual display of the attack/decay/sustain/release envelope shape

Master Volume

Oscillators (VCO1, VCO2, VCO3)

Three independent oscillators with PolyBLEP anti-aliasing. Each oscillator has:

FM (Frequency Modulation)

FM Algorithms:

How FM works:

• At amount = 0, oscillators run independently (standard subtractive mode).
• At amount = 1, maximum frequency modulation is applied, creating complex sidebands.
• Use the Algo selector to choose different modulation routings.

Filter

Filter envelope behavior: When Env > 0, the cutoff frequency sweeps from its base value toward 20 kHz during the attack time, then returns to the base value during the decay time. At Env = 1, the sweep reaches the full 20 kHz range.

LFO

There are two independent LFOs (LFO and LFO2) with the same parameters:

LFO Targets:

Noise

Envelope (ADSR)

9. Piano Roll

The Piano Roll is an alternative view to the Pattern Panel step grid. It displays notes on a vertical pitch axis (MIDI-style) with time on the horizontal axis. Open it from the toolbar or view switcher.

Layout

• Keys column (left): piano keyboard showing MIDI note names (C3, C#3, D3, etc.)
• Grid: time flows left-to-right, pitch flows bottom-to-top
• Note bars: horizontal rectangles — length = duration, vertical position = pitch

Interactions

Editing velocity & pitch: dragging a note and Shift + Arrow on the selected note edit its velocity (up/down) and pitch (left/right), with the same editing gauge as the pattern grid: arc, note name, new value, and a ring on the note. The note is previewed while it changes, a drag never deletes it, and the whole gesture undoes as one step. The pitch is kept inside the visible keyboard (MIDI 12–108, shifted by the track pitch), so a note can never be transposed off the grid.

Page navigation: The piano roll displays one page of beats at a time (default: 4 beats). Use the page buttons in the toolbar to navigate between pages.

10. Patterns Panel

The Patterns Panel manages all patterns in the current song. Open it from the toolbar pattern selector.

Pattern List

• Shows all patterns in the current song
• Click a pattern to select it and load it into the sequencer
• Double-click a pattern name to rename it

Actions

Song Name

Double-click the song name at the top to rename it. Default: "Untitled".

11. Pattern Settings

The Pattern Settings panel provides quick access to pattern-level parameters. On mobile, it opens from the toolbar gear icon. On desktop, it's accessible from the toolbar.

12. Drumkit Manager

The Drumkit Manager lets you inspect and edit individual samples in a drumkit. Open it from the toolbar or Track Editor.

Header Actions

Sound List

• Lists all samples in the currently loaded drumkit
• Click a sample to select it and view details
• Each sample row has a ▶ play button to audition the sound

Sample Details

Footer Actions

13. About Panel

The About Panel displays application information and PWA installation options. Open it from the toolbar.

Info Tab

PWA Tab

• Install App — Button to install orDrumbox as a Progressive Web App (appears when supported by the browser)
• Website — Link to ordrumbox.com
• Source — Link to the GitHub repository

14. Mobile Tab Bar

On mobile viewports (width ≤ 768px), a bottom tab bar replaces the toolbar for navigation between views.

Tabs

The active tab is highlighted. Tapping the same tab again does nothing. Switching views dispatches the corresponding event and updates the main display.

15. Keyboard Shortcuts

Context menus (pattern grid, piano roll) show their target in the header — track name, step or key. Entries that do not apply (empty clipboard, no note under the cursor) are greyed out. A menu closes on outside click, on another right-click or on Escape.

16. Audio Signal Flow

Per-Track Signal Chain

Sample/Synth → Filter → Saturation → Dry Gain → Reverb → Delay → Stereo Panner → Mixer Bus
    

Master Bus Signal Chain

Mixer Bus → Pre-Gain → Compressor → Low-cut Filter (35 Hz) → High-cut Filter (18.5 kHz) → Master Gain → Analyser → Speakers
    

All tracks feed into a shared mixer bus. The master bus applies pre-gain, then compression, then filters and final gain before reaching the output.

17. Installation & Offline Use

orDrumbox v2 can be used in three different ways:

1. Web Application

Simply visit the website in any modern browser. Note that an internet connection is required for the initial load.

2. Progressive Web App (PWA)

You can install orDrumbox directly from your browser:

• Desktop (Chrome/Edge): Click the "Install" icon in the address bar.
• Mobile (iOS/Android): Use "Add to Home Screen" from the browser menu.

Once installed, the application will have its own icon and window, and can function offline thanks to the integrated Service Worker.

3. Desktop Application

orDrumbox will be available soon