Slimmable NAM: Neural Amp Models with adjustable runtime computational cost
Steven Atkinson
TL;DR
Problem: NAMs for virtual-analog guitar gear are often CPU-intensive, limiting real-time use on CPU-limited devices. Approach: introduce Slimmable NAMs that post-training reduce width from $c$ to $c'$ by truncating $\mathbf{W} \in \mathbb{R}^{c \times c \times k}$ and $\boldsymbol{b} \in \mathbb{R}^{c}$ to $\mathbf{W}' \in \mathbb{R}^{c' \times c' \times k}$ and $\boldsymbol{b}' \in \mathbb{R}^{c'}$, with $d_x=d_y=1$ for mono audio, trained with dry/wet pairs and random $1 \le c' \le c$ per batch, and deployed in a real-time plugin with a GUI slider controlling width $c'$, using a single WaveNet module. Contributions: includes width-truncation method for NAMs, randomized-width training protocol, real-time plugin demonstration, and open-source code. Impact: enables musicians to trade off accuracy and compute on the fly without retraining, broadening accessibility of neural virtual-analog effects.
Abstract
This work demonstrates "slimmable Neural Amp Models", whose size and computational cost can be changed without additional training and with negligible computational overhead, enabling musicians to easily trade off between the accuracy and compute of the models they are using. The method's performance is quantified against commonly-used baselines, and a real-time demonstration of the model in an audio effect plug-in is developed.
