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

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

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, euclidian 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

Export filenames: ordrumbox-{patternName}.{ext}

MIDI Export details:

• Track 0: Tempo + time signature
• Track 1+: One MIDI track per instrument
• Drum tracks → MIDI channel 10
• Muted tracks are excluded

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.

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

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

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