DrumCraker is a free drum sampler VST3 plugin optimized for Linux and macOS, fully compatible with DrumGizmo drum kits. Designed for low-latency performance and realistic drum sound reproduction.

• DrumGizmo Compatible: Load any DrumGizmo drum kit (XML format)
• Separate Kit & MIDI Map Loading: Independent control over drum kit and MIDI mapping
• Multi-Channel Output: Up to 16 stereo buses with intelligent instrument routing
• Smart Routing: Automatic grouping by instrument type (Kick→Bus1, Snare→Bus2, etc.)
• Velocity Layers: Automatic sample selection based on MIDI velocity
• High-Quality Resampling: Lagrange interpolation for automatic sample rate conversion
• Asynchronous Loading: Non-blocking sample loading in background thread
• Optimized Performance: Unordered maps and instrument caching for minimal CPU usage

• Zero Memory Leaks: Thread-safe memory management with automatic cleanup
• 64 Polyphonic Voices: Simultaneous note playback with intelligent voice stealing
• Lock-Free Audio Thread: No allocations or locks in real-time processing
• Master Volume Control: -60dB to +12dB range with smooth gain adjustment
• Multi-Bus Rendering: Efficient per-bus voice rendering with zero overhead in stereo mode
• Optimized Lookups: Hash-based caching for instrument and sample access

DrumCraker adds natural human feel to MIDI performances, working with both fixed and variable velocity tracks:

• Velocity Humanization (0-100%, default 8%): Adds natural velocity variation

  • Perfect Gaussian distribution (Box-Muller transform)
  • Works on ANY input velocity (fixed or variable)
  • With 8%: each note varies ±8% from its original velocity
  • Prevents mechanical "machine gun" effect on repeated notes

• Timing Humanization (0-20ms, default 5ms): Adds natural timing groove

  • Gaussian distribution for realistic human timing
  • Velocity-adaptive bias: loud notes rush slightly, soft notes drag
  • Works on perfectly quantized MIDI
  • Creates natural groove even on programmed drums

• Round Robin Mix (0-1, default 0.7): Anti-repetition sample rotation

  • 0.0 = Pure velocity matching (most consistent dynamics)
  • 0.7 = Hybrid intelligent (recommended): 93% penalty on last sample, velocity-aware
  • 1.0 = Pure rotation (maximum variation)
  • Always uses pool of 4 closest samples by velocity
  • Prevents same sample from playing consecutively

• OS: Linux (Debian, Ubuntu, Fedora, Arch, etc.)
• Audio: ALSA, JACK, or PipeWire
• CPU: x86_64 with SSE2 support
• RAM: 4GB minimum (depends on drum kit size)
• Compiler: GCC 9+ or Clang 10+ with C++17 support
• Build Tools: CMake 3.15+, Git

• OS: macOS 10.13 (High Sierra) or later
• Audio: CoreAudio
• CPU: Intel x86_64 or Apple Silicon (M1/M2/M3)
• RAM: 4GB minimum (depends on drum kit size)
• Compiler: Xcode Command Line Tools with C++17 support
• Build Tools: CMake 3.15+, Git

1. Download the latest .vst3 from GitHub Releases
2. Extract and install:

# Install for current user
cp -r DrumCraker.vst3 ~/.vst3/

# Or install system-wide (requires sudo)
sudo cp -r DrumCraker.vst3 /usr/lib/vst3/

# Install dependencies (Debian/Ubuntu)
sudo apt install build-essential cmake git pkg-config \
    libasound2-dev libfreetype6-dev libfontconfig1-dev \
    libx11-dev libxrandr-dev libxinerama-dev libxcursor-dev \
    libcurl4-openssl-dev libwebkit2gtk-4.1-dev libgtk-3-dev \
    libgl1-mesa-dev

# Clone repository
git clone https://github.com/Wamphyre/DrumCraker.git
cd DrumCraker

# Build and install
./build.sh
cp -r releases/DrumCraker.vst3 ~/.vst3/

The build script automatically:

1. Checks dependencies: Verifies all required system libraries are installed
2. Clones JUCE framework: Downloads JUCE 8.0.10 (if not present)
3. Compiles the plugin: Optimizations enabled (-O3 -march=native -flto)
4. Copies to releases/: Creates ready-to-install VST3 bundle
5. Includes resources: Embeds background image in VST3 bundle
6. Cleans up: Removes temporary build files (keeps JUCE for future builds)

1. Open your DAW (Reaper, Ardour, Bitwig, etc.)
2. Create a MIDI track and load DrumCraker as an instrument
3. Click "LOAD DRUMKIT" and select the drum kit XML file
4. Click "LOAD MIDI MAP" and select the MIDI map XML file
5. Adjust Master Volume to your preferred level (default: 0dB)

DrumCraker is compatible with all DrumGizmo drum kits. You can download free kits from:

• DrumGizmo Official Kits

Popular kits include:

• DRSKit: Versatile rock/jazz kit
• CrocellKit: Heavy metal kit
• MuldjordKit: All-purpose kit

DrumCraker automatically routes instruments to separate buses for advanced mixing:

• Automatic Grouping: Instruments are grouped by type (Kick, Snare, HiHat, Tom, Cymbal, etc.)
• Up to 16 Buses: Each group gets its own stereo bus for independent processing
• Intelligent Assignment: Based on DrumGizmo kit's instrument groups
• Stereo Fallback: If only one bus is enabled, all instruments mix to main output
• DAW Integration: Enable/disable buses in your DAW's mixer for flexible routing

Example Routing:

• Bus 1: Kick drums
• Bus 2: Snare drums
• Bus 3: Hi-hats
• Bus 4: Toms
• Bus 5: Cymbals
• Bus 6+: Additional percussion

This allows you to apply separate EQ, compression, reverb, and effects to each drum group directly in your DAW.

• Range: -60dB to +12dB
• Default: 0dB
• Purpose: Overall output level control

• Range: 0.0 to 1.0 (0-100%)
• Default: 0.08 (8%)
• Purpose: Adds natural velocity variation to ANY MIDI input
• How it works:
  • Perfect Gaussian distribution (Box-Muller transform)
  • Adds variation on top of existing MIDI velocity
  • Works even if all MIDI notes have same velocity (e.g., all at 120)
  • With 8%: velocity 100 becomes ~92-108, velocity 120 becomes ~110-130
• Use Cases:
  • 0.05-0.10 (5-10%): Subtle realism, tight playing
  • 0.10-0.20 (10-20%): Natural human feel (recommended)
  • 0.20-0.40 (20-40%): Loose, expressive, dynamic playing

• Range: 0.0 to 20.0 ms
• Default: 5.0 ms
• Purpose: Adds natural timing groove to MIDI (even perfectly quantized)
• How it works:
  • Gaussian distribution for realistic human timing
  • Velocity-adaptive bias: loud hits rush ~20%, soft hits drag ~20%
  • Creates natural groove on programmed drums
• Use Cases:
  • 2-5ms: Tight, professional studio feel
  • 5-10ms: Natural human timing (recommended)
  • 10-20ms: Loose, laid-back, relaxed grooves

• Range: 0.0 to 1.0
• Default: 0.7
• Purpose: Prevents "machine gun" effect on repeated notes
• How it works:
  • Selects from pool of 4 closest samples by velocity
  • 93% penalty on last used sample (with default 0.7)
  • Weighted random selection respects velocity layers
  • Never plays same sample twice in a row
• Settings:
  • 0.0: Pure velocity matching (most consistent dynamics)
  • 0.7: Hybrid intelligent (recommended - natural + velocity-aware)
  • 1.0: Pure rotation (maximum variation, less velocity-accurate)

• Sample Rate: Automatic conversion to project sample rate
• Buffer Size: Optimized for 32-512 samples
• Latency: < 1 buffer (< 1.3ms @ 64 samples/48kHz)
• Memory: Zero leaks, efficient cleanup on kit changes
• CPU Usage: Optimized with hash-based lookups and instrument caching (15-25% reduction vs v1.1.1)

• Automatically normalizes DrumGizmo power values to 0-1 range
• Selects samples within 25% tolerance of target velocity
• Falls back to 4 closest samples if no candidates found (for round robin pool)
• Respects MIDI velocity for dynamic expression
• Humanization works on top of velocity selection

• Algorithm: Lagrange 4-point interpolation
• Quality: ~80dB SNR, transparent for musical content
• Performance: Processed during asynchronous loading
• Supported Rates: Any source rate (44.1kHz, 48kHz, 88.2kHz, 96kHz, etc.)

• Add compatibility for Hydrogen drumkits (too hard but possible)
• MIDI learn for parameter automation

• Compatible with: DrumGizmo drum kits
• Framework: JUCE
• Optimization: Designed for Linux and PipeWire

If you find DrumCraker useful and want to support its development, consider buying me a beer! ☕

Made with ❤️ for the Linux audio community