The Universal Launchpad Sampler is a high-performance, browser-based audio performance tool designed specifically for Novation Launchpad hardware. It allows users to load, trim, and manipulate audio samples in real-time using a grid-based interface that synchronizes with physical MIDI controllers.
The application supports two primary MIDI mapping modes:
- Novation Launchpad MK1 Mode: Optimized for the original Launchpad (Original, S, Mini) using the 16 \times 8 internal note mapping.
- Linear / Programmer Mode: Designed for modern Launchpads (MK2, Mini MK3, X, Pro) using a standard 8 \times 8 grid (0-63 or 11-88).
Important Note on Hardware Activation: Depending on your model, the Launchpad may not send MIDI data immediately. You may need to manually switch the device into the correct mode by pressing the "User 1", "Note", or Arrow keys on the hardware to enable the MIDI grid.
- Initialize: Upon opening the application, select your hardware model from the setup box. Click the "INITIALIZE" button.
- MIDI Access: Grant the browser permission to access MIDI devices.
- Loading Audio:
- Click on the file name area of a pad or Drag & Drop an audio file onto a pad.
Each of the 64 pads acts as an independent sampler unit with the following features:
Audio Manipulation
- Waveform Display: Visual representation of the loaded sample.
- Trim Handles: Click and drag the edges of the waveform to set the Start Point (Green) and End Point (Red).
- Playback Position: Click anywhere within the waveform to set a custom start offset.
- VOL (Volume): Adjusts the gain of the specific pad (0.0 to 1.5).
- PIT (Pitch): Changes the playback rate/pitch (0.2x to 3.0x).
Playback Modes
- LOOP: When active, the sample repeats indefinitely within the trimmed area.
- REV (Reverse): Plays the sample backwards.
- Retrigger (Hardware): Pressing a Launchpad button immediately restarts the sample from the start point for "finger drumming" performance.
Due to browser security restrictions, web applications cannot store local file paths. The Sampler uses a Relink System to solve this:
- 💾 SAVE CONFIG: Saves all pad settings (volume, pitch, trim points, filenames) into a .json file.
- 📂 LOAD CONFIG: Restores the settings from a previously saved JSON file.
- 🔗 RELINK: After loading a config, click this and select the folder/files from your hard drive. The app will automatically match the files to the correct pads based on their filenames.
- ■ STOP ALL: Immediately kills all active audio sources.
The Sampler provides real-time visual feedback on your Launchpad:
- Off / Dim: No sample loaded.
- Amber: Sample loaded and ready.
- Green: Sample currently playing.
- Yellow: Sample is paused.
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Browser: Google Chrome, Edge, or any browser supporting the Web MIDI API and Web Audio API.
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Firefox & Linux Users: In certain environments (especially Linux), the Web MIDI API may only be available in a "Secure Context" or via localhost.
If the application does not detect your MIDI device when opened as a local file (file://...), you must run it through a local web server.
Command: Navigate to the folder in your terminal and run: python3 -m http.server 8000
Access: Then open http://localhost:8000 in your browser.
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Context: Audio will only initialize after the first user interaction (clicking the "INITIALIZE" button).
- MIDI not working: Ensure your Launchpad is connected before opening the browser. Check if other MIDI software is "hogging" the device. Ensure "User 1" or the correct mode is active on your Launchpad.
- No Sound: Ensure your browser tab is not muted and the "INITIALIZE" button was clicked.
- Relink failed: Ensure the filenames of the audio files on your disk exactly match the filenames displayed on the pads when the config was saved.
https://bmpydev.github.io/universal-launchpad-sampler/
Important: In the file dialog, simply select all files in your sample folder. The application will automatically scan the batch and assign the correct files to their designated pads.