NeuralBlender

A simple, efficient but feature-rich amp modeling plugin based on RTNeural and NeuralAmpModeler (NAM)

Features:

• Supports nam A1, nam A2, aidax, and json model files.
• Full impulse response (convolution) for cab sim
• Reads gzipped files
• Complete STOMPBOX -> preEQ -> AMP -> postEQ -> CAB/IR signal flow with 3 "banks" of models
• 8-band parametric pre and post EQ
• Can load up to 4 models on each bank simultaneously (each model either NAM/json/aidax or IR)
• Can either blend them (normal) or switch between them like "channels" (exclusive mode)
• Standalone app and LV2 plugin
• Proper multithreading with UI and loader threads separate from DSP
• VU meters can be disabled to save a tiny bit of CPU
• Calibration target dB is now a user defined setting
• "Linked" calibration mode follows loudest model which has calib. enabled
• Calibration can be tuned for guitar or bass
• Tuner, can be enabled/disabled to save a bit of CPU
• Volume ramping/crossfade when loading, switching etc. to avoid clicks
• Each model slot / lane has:
  • input gain if not an impulse response
  • if IR, pitch shift +- 1 octave in 1/100 semitone increments
  • output gain
  • dry out gain
  • pre-delay for phasing correction/effects
  • optional DC flip for more phasing effects
  • optional level calibration to target dB

On my Intel Core7 ultra, it loads 5 or 6 models in the middle of a busy live session, 64 sample buffers / 3 periods, and DSP load typically stays below 40%, no xruns. (with DSP threads pinned to p-cores)

Features considered for future versions: VST plugin, stereo routing, series mode(s), optionally more than 4 lanes per model bank, lane groups, DSP load-splitting/balancing etc...

Demo: https://soundcloud.com/delt01/snakeskin All the guitars and bass in this track are straight DI's processed through NeuralBlender with a bit of reverb, and flanger at one spot. The wah effect was achieved by automating one of the pre-EQ bands. NAM models used are available on https://tone3000.com

Binary distribution

Included is a .deb package that was tested on Ubuntu/Mint "Noble Numbat" and "Resolute Raccoon" GNU/Linux distributions.

Compiling the source code

Compiles and installs with cmake. Required libs / utilities to build:

• fftw-float (core, required)
• lv2 (for LV2 plugin)
• jack (for standalone app)
• cairo/x11 (for GUI)
• libsoundfile (for .wav file loading)
• xxd utility, for inline data
• eigen3 (included)
• libsamplerate (implemented own resampling)

On debian/ubuntu/mint, just run:

sudo apt install git cmake libfftw3-dev lv2-dev libjack-dev libcairo2-dev libsndfile1-dev xxd

On other distributions, the package names (and package system) are probably different, but still available.

To grab the code, build and install, run something like:

git clone https://git.code.sf.net/p/neuralblender/code neuralblender
cd neuralblender
mkdir build
cd build
cmake ..
make -j$(nproc) && sudo make install

To uninstall, go back to the same build directory and run:

sudo make uninstall

For the standalone version, see --help text for more info/options

Supported systems

Should compile and work fine on any POSIX-compliant OS including Linux, MacOS (to be fixed), FreeBSD, etc. For now UI uses X11, but recent rewrite should make it easy to port to other graphic systems.

Tested on:

• Void Linux
• MX Moksha
• Linux Mint
• Fedora
• FreeBSD

MacOS: Expected to work soon, currently needs to be fixed. The only Mac i have is from 1986.

Android: Not really interested in supporting it, but if there's enough demand i'll make an effort.

W**dows: Don't do microsuck malware. It's bad for you, and for everyone else.

License

NeuralBlender is licensed under the GNU General Public License v3.0 (GPL-3.0-or-later). See the LICENSE file for full license text.