Overview

The VerbFX firmware offers exploration of a multi-effects reverb processor, using the NISPS approach to ML.

VerbFX

VerbFX is a multi-effects processor built around a Freeverb-based reverb algorithm with a filterbank and delays. 47 sound processing parameters are controlled by the joystick. Six effect routing options can be individually enabled or disabled via the FX Enable screen.

Signal Flow

Input → FilterBank → Delays (Short / Medium / Long) → Reverb → Wet/Dry Mix → Output

The FilterBank can receive feedback from the delay outputs. The delay outputs can also be routed into the reverb input.

Effect Blocks

  1. FilterBank — 8 bandpass filters in parallel.
  2. Reverb — Freeverb algorithm (8 low-pass feedback comb filters + 4 allpass filters)
  3. Short Delay — 512 sample delay buffer
  4. Medium Delay — 2048 sample delay buffer
  5. Long Delay — 16384 sample delay buffer
  6. Delay → Reverb — Routes the delay mix into the reverb input

Inputs

The processor takes a stereo input. Left and right channels are summed to mono before processing.

Outputs

Mono processed sound is output to both channels of the line out and headphone sockets.

NISPS

When you indicate a reward, you are rewarding (negatively or positively) how a particular joystick position is mapped to the effect sound it’s producing. As you indicate preferences for these settings, the NISPS system will start to tune the mappings towards your preference. See the NISPS documentation for further info.

Physical Controls

  • Rotary Encoder: Navigate between screens
  • Momentary A Up: Scramble neural network
  • Momentary A Down: Jolt neural network
  • Momentary B Up: Positive reward
  • Momentary B Down: Negative reward
  • Joystick: Explore
  • Joystick button: Positive reward placement — drag a sound to a different place and release to positively reward it in this position
  • Toggle A Down: Clear replay memory
  • Knob X: Learning rate
  • Knob Y: Wet/Dry Mix
  • Knob Z: Exploration noise (turned off when all the way to the left)
  • Knob G: Volume

Screens

Navigate between screens using the rotary encoder.

RL

Info on the neural network - the outputs, the current error rate, the number of datapoints in replay memory, and the most recent command.

Focus

Selecting one or more items in the focus menu freezes all unfocused neural network outputs at their current value, so that NISPS only changed the focused values. This let’s you do detailed training, e.g. if you just want to adjust the reverb but not other sounds.

FX Enable

Toggle each of the six effect blocks on or off: FilterBnk, Reverb, ShortDly, MedDly, LongDly, Dly→Verb.

Voice Spaces

Choose a voice space by pushing the rotary encoder to focus the selector. Move the encoder to choose a space and then push again to confirm the selection.

Available voice spaces:

  1. Default
  2. Resonant
  3. Soft
  4. Cathedral
  5. Shimmer
  6. Chamber
  7. Metallic
  8. Granular
  9. Diffuse
  10. Dark
  11. Bright
  12. Harmonic

These voice spaces bias the neural network mappings in particular directions.

NN Inputs

Shows the inputs to the neural network.

Messages

Various messages logging interactions with the system.

Save Model

Tap on a slot to save a model and current voice space,

Load Model

Tap on a slot to load a model.

Input Source

Choose from

  • the joystick that matches your hardware (3D or 4D)
  • machine listening analysis of the line input (allows the system to adapt to different sounds)
  • various configurations of MIDI controllers

Help

Shows what the various controls do.

System Info

System information about the MEMLNaut and current firmware.

MIDI

The firmware sends out the first 16 neural network outputs as MIDI controllers, so you can use the MEMLNaut to control your hardware synths.

Files

Code

https://github.com/MusicallyEmbodiedML/MEMLNaut-NISPS

Firmware Download

https://github.com/MusicallyEmbodiedML/MEMLNaut-NISPS/releases/tag/VerbFX_1.1.0

See the firmware guide for installation instructions.