Homecrate Drum — 16-Pad Drum Sampler
Homecrate Drum is a 16-pad drum sampler and step sequencer, available as a standalone app and as an AUv3 plugin you can load directly inside Homecrate. It lets you trigger and sequence your own samples using a classic MPC-style grid, with per-pad volume and pitch controls, a built-in step sequencer, and a preset system for saving complete kits.
🟢 New to drum machines? Skip to Quick Start below — you can make a beat in under two minutes without reading anything else.
🔵 Coming from hardware MPC / drum machines? The pad layout uses General MIDI notes 36–51, the step sequencer records in real time with optional quantize, and MIDI clips export directly to Homecrate’s timeline via clipboard copy.
Quick Start
- Load Homecrate Drum as an AUv3 instrument plugin on an audio track in Homecrate
- Tap the folder icon (📁) on any pad to load a sample from your files
- Tap the pad — it triggers the sample and flashes neon green
- Tap the grid icon (⊞) in the header to open the step sequencer
- Tap cells in the sequencer grid to program your beat
- Tap ▶ Play to hear it loop
Loading Homecrate Drum in Homecrate
See Loading & Removing Plugins for the general steps. Homecrate Drum appears under the Instruments tab in the Plugin Browser.
Once loaded on an audio track, create a MIDI track and route it to Homecrate Drum via the AUv3 Instrument picker in the MIDI channel strip. Incoming MIDI notes 36–51 map directly to pads 1–16. See Instrument Plugins & MIDI Routing.
The Interface
[SCREENSHOT: Full Homecrate Drum interface — header transport, 4×4 pad grid]
The interface has two main sections:
- Header bar — transport controls, sequencer toggle, BPM, loop length, presets, host sync
- 4×4 pad grid — 16 individual sample pads
The Pad Grid
[SCREENSHOT: Single pad cell with all elements labeled]
Each pad contains:
| Element | Description |
|---|---|
| Pad label (top-left) | The drum instrument name: KICK, SNARE 1, HH CL, etc. |
| Activity dot (top-right) | Flashes neon green when the pad fires |
| Sample name (bottom) | The filename of the loaded sample, or ”— no sample —” |
| 📁 folder button (bottom-left) | Tap to load a new sample file for this pad |
| VOL knob | Per-pad output volume (0%–100%). Drag upward to increase. |
| Pitch knob | Per-pad pitch offset in semitones (±24 st). Shows +/− value above the knob; glows green when non-zero. |
Triggering Pads
Tap any pad to trigger its sample immediately. The pad flashes and the activity dot glows. Touch response is processed at the UIKit layer (not SwiftUI) so there is zero visual delay between your tap and the sound.
Pads respond to MIDI note-on messages on any channel. The note mapping is fixed: KICK = note 36, RIM = 37, SNARE 1 = 38 … RIDE = 51. See the Pad Map below.
Per-Pad Volume
Drag the VOL knob upward to increase volume, downward to decrease. The percentage is shown above the knob. This is independent of the main output level.
Per-Pad Pitch
Drag the pitch knob upward to pitch the sample up (in semitones), downward to pitch it down. The offset is shown above the knob as “+N” or “−N”. At ±0 the label is grey; any offset makes it glow green as a reminder.
The pitch knob is useful for tuning kick drums, making a snare sound tighter (+1 or +2 semitones), or creating tom fills from a single snare sample at different pitches.
Loading Samples
Tap the 📁 folder icon on any pad to open a document picker. Navigate to any audio file on your device — from Files, iCloud Drive, or any other location.
[SCREENSHOT: Document picker showing audio files]
Supported formats: WAV, AIFF, CAF, M4A, and any format iOS can open via AVAudioFile.
Once loaded, the sample is copied into Homecrate Drum’s private sample library so it remains available even if the original file is moved or deleted. The sample name shown on the pad is the filename.
Samples are stored in the app group container under CoolSSamples/. They persist across sessions and are referenced by filename in saved presets. If you replace a file in the library with a different file of the same name, all presets using that name will load the new file.
Pad Map
Homecrate Drum uses General MIDI drum note assignments. These are universal — any drum machine, DAW, or MIDI controller that follows the GM spec will map to the same pads.
| Pad | Label | MIDI Note | Color |
|---|---|---|---|
| 1 | KICK | 36 (C2) | Red |
| 2 | RIM | 37 (C#2) | Orange |
| 3 | SNARE 1 | 38 (D2) | Blue |
| 4 | CLAP | 39 (D#2) | Purple |
| 5 | SNARE 2 | 40 (E2) | Cyan |
| 6 | LO FLR TM | 41 (F2) | Amber |
| 7 | HH CL | 42 (F#2) | Neon Green |
| 8 | HI FLR TM | 43 (G2) | Yellow |
| 9 | HH PED | 44 (G#2) | Lime |
| 10 | LO TOM | 45 (A2) | Peach |
| 11 | HH OP | 46 (A#2) | Mint |
| 12 | LO-MID TM | 47 (B2) | Pink-Red |
| 13 | HI-MID TM | 48 (C3) | Pink |
| 14 | CRASH 1 | 49 (C#3) | White |
| 15 | HI TOM | 50 (D3) | Salmon |
| 16 | RIDE | 51 (D#3) | Slate |
You don’t need to memorize these. The labels on the pads tell you exactly what each one is. The note numbers only matter if you’re triggering pads from a MIDI keyboard or an external controller.
The Header Transport
[SCREENSHOT: Header bar with all controls labeled]
Transport Buttons
| Button | Action |
|---|---|
| ▶ Play | Starts the step sequencer loop |
| ⏺ Record | Clears the current pattern and starts recording — pads you tap are captured with timing intact |
| ⏹ Stop (tap Play/Record again) | Stops playback or recording |
Q (Quantize)
When lit, recorded pad taps are snapped to the nearest 16th-note grid position. When off, your taps are recorded at the exact timing you played them.
Leave Quantize on until you’re comfortable with the timing of the sequencer. It makes everything sit perfectly on the grid.
With Quantize off, fractional beat positions are preserved in the exported MIDI clip, giving you real-feel timing in Homecrate’s piano roll.
Metronome
Toggles the built-in click track during playback and recording. The click fires on every beat (accented on beat 1 of each bar).
⊞ Grid (Step Sequencer Toggle)
Opens or closes the floating step sequencer overlay. See The Step Sequencer.
Loop Length
Use the +/− stepper to set the pattern length from 1 to 4 bars. All pads share the same loop length.
BPM
Use the +/− stepper (in steps of 5 BPM) to set the tempo from 60 to 240 BPM.
Host BPM
When Host BPM is toggled on, the BPM is read from Homecrate’s project tempo automatically. The BPM stepper is disabled. Any tempo change in Homecrate updates Homecrate Drum in real time.
Host BPM is polled from the AUv3 musical context block every 64 render cycles. If you need the sequencer to stay locked to a tempo-automation track in Homecrate, keep Host BPM on.
Host Transport
When Host transport is toggled on, Homecrate Drum’s sequencer starts and stops in response to Homecrate’s Play/Stop transport. MIDI Real Time messages (0xFA Start, 0xFB Continue, 0xFC Stop) drive this behavior.
Preset Library (☰)
Opens the saved kits list. See Kits & Presets.
Save Kit (↓)
Opens the Save Kit sheet to name and save the current kit. See Kits & Presets.
The Step Sequencer
Tap the ⊞ grid icon in the header to open the step sequencer overlay. It floats above the pad grid and can be dragged anywhere on screen.
[SCREENSHOT: Step sequencer overlay — full view]
Layout
- Rows — one per drum pad (16 rows total), labeled in color on the left
- Columns — 16th-note steps, one column per step, scrollable horizontally for multi-bar patterns
- Bar markers — bright green “B1”, “B2” etc. at the start of each bar
- Beat markers — dimmer lines showing beats 2, 3, 4 within each bar
- Playhead — a neon green column highlight that advances through the grid during playback
Programming Steps
Tap any cell to activate that drum hit at that step. The cell fills with the pad’s color. Tap it again to remove it.
[SCREENSHOT: Tapping a step cell to activate it]
The Playhead Ruler
The ruler row at the top shows bar and beat markers. During playback, a green highlight sweeps across the current step position in real time. Only the ruler re-renders on each tick — the rest of the grid is static — so performance stays smooth even on large patterns.
Per-Step Note Editing (Long-Press)
Long-press any active step cell to open the Step Note Editor for that hit.
[SCREENSHOT: Step Note Editor sheet]
| Parameter | Range | Description |
|---|---|---|
| Velocity | 1–127 | How hard the hit plays. Affects both volume and feel on velocity-sensitive samples. The cell’s fill opacity reflects the velocity value. |
| Pitch Offset | −24 to +24 semitones | Shifts the pitch of this specific hit, independent of the pad’s global pitch knob. Useful for melodic toms or pitched percussion fills. |
| Repeat Count | 1–8 | The number of times this hit retriggers within its step. Shows as “Nx” on the step cell. |
| Repeat Spacing | 1/4, 1/8, 1/16, 1/32 | The interval between repeats. 1/32 gives a tight machine-gun roll; 1/4 gives a quarter-note subdivision. |
Velocity is the most useful thing to tweak here. Lower the velocity on offbeat hi-hats and ghost snares to add dynamics and make your beat sound more human.
Repeat + Spacing is implemented as multiple triggerPad calls dispatched on a userInteractive queue with asyncAfter delays. The delays are computed from the current BPM at the moment the step fires, so tempo changes mid-pattern are reflected immediately on the next step.
Clear All
Tap 🗑 Clear in the sequencer’s footer to remove all steps from the current pattern.
Export MIDI (Copy MIDI)
Tap Copy MIDI to export the current pattern as a MIDI clip JSON payload, copied to the clipboard.
In Homecrate:
- Switch to the MIDI tab
- Long-press a blank MIDI track row
- In the popup, tap Paste — the pattern appears as a clip at the playhead position
The exported clip uses the same MIDI note assignments as the pad map, so it routes correctly to Homecrate Drum (or any GM drum machine) via a MIDI track.
[SCREENSHOT: Pasting a Homecrate Drum clip into Homecrate's MIDI timeline]
The clipboard JSON matches the MidiClipPayloadRecord schema used throughout Homecrate, so it’s also compatible with any Homecrate workflow that consumes that format — including the AI Music Chat beat generator and Homecrate’s own drum step sequencer editor.
Kits & Presets
A kit is a complete snapshot of all 16 pads: their loaded samples, volume levels, and pitch offsets. Kits are saved and recalled independently of the step sequencer pattern.
Saving a Kit
- Tap ↓ Save Kit in the header
- Enter a name
- Tap Save
[SCREENSHOT: Save Kit sheet]
Loading a Kit
- Tap ☰ Preset Library in the header
- Tap Load next to any saved kit
[SCREENSHOT: Preset Library list]
Deleting a Kit
In the Preset Library, swipe left on any kit and tap Delete.
Persistence
Kits are stored in UserDefaults (keyed by kit name, serialized with NSKeyedArchiver). They persist across app launches and survive AUv3 plugin reloads. When a kit is loaded inside Homecrate, it’s also saved as part of the plugin’s fullState so the project recalls the correct kit when reopened.
The fullState dictionary stores sample filenames (not full paths) keyed as pad0Sample through pad15Sample, plus per-pad volume and pitch values. Samples are resolved against the shared sample library directory at load time. If the library directory moves (e.g. after a device restore), samples will not be found until re-imported.
Tips
- Start with just kick and snare before adding hi-hats — a sparse beat that grooves beats a busy one that doesn’t
- Use the Host BPM and Host Transport toggles so Homecrate Drum stays locked to Homecrate without any manual sync work
- Record a pattern in real time with Quantize on, then use the step editor to clean up any wrong hits
- Lower-velocity ghost notes on SNARE 2 (pad 5) under your main snare pattern create a professional R&B/hip-hop feel without extra samples
- Use per-step pitch offset on toms to create melodic fills — the same tom sample played at −4, 0, +4, and +7 semitones gives you a full tom run from one file
- The Copy MIDI export captures real-feel timing when Quantize is off — useful for importing organic-feeling patterns into Homecrate’s piano roll for further editing
- Open hi-hat (HH OP, pad 11) should not share a step with closed hi-hat (HH CL, pad 7) — a real hi-hat can only be in one position at once