NAM A2 Proves Superior Accuracy & Performance

I've been a big proponent of Neural Amp Modeler here largely to the open-source ideal of not having your guitar tone locked to any specific proprietary platform, but with the release of the new A2 architecture on June 2nd, TONE3000 (in partnership with Steve Atkinson) have provided strong evidence that NAM really is the leading technology for modeling guitar and bass amps and other gear.

NAM A1 was already world-class, the data show, but A2 beats it noticeably in blind listening and quantitative accuracy tests. Notably the A2-Lite size (which is stored in the same file as the corresponding full-size model) still beats Neural DSP V2 and V1, IK Multimedia’s ToneX, and Line 6’s Proxy in the same tests!

(Line 6 was a noticeable laggard)

The raw listening test data and test code are available online for anyone interested in auditing or reproducing the results. At the bottom of their guide, they even explicitly invite people to try to poke holes in their methodology!

I am certainly interested in learning more about how they calculated their bayesian elo scores, but they at least explain the metrics that went into it.

A2 is also demonstrably more performant than A1. And with A2-Lite, that enables running on common consumer hardware.

The biggest architectural change was changing the activation function from Tanh to a leaky ReLU, which is easier to compute and frees up headroom for a larger neural network. Also, there's a longer "receptive field" of samples (6,350 vs ~4100 in A2) in your signal chain used in predicting the output sound, which T3K points out as a reason that A2 can capture more types of gear like compressors. There are also specific mitigations to reduce aliasing and ring artifacts compared to A1.

I have updated the player and models here in the Tubes & Code "playable articles" series to use NAM A2, which lets you try it in your browser without any downloads. A2's accuracy is great for my goal of enriching online music gear content with interactivity.

More types of gear? Let's try a compressor!

A few months ago, during my efforts to capture my amp with various combinations of pedals in front of it, I captured my rig with my Xotic SP Compressor in front of my Marshall DSL5CR. Since NAM A2 should improve the ability to model this combination, I included some A2 models here (including one without the compressor for comparison) that you can try here by loading the player in my site or downloading for your DAW:

Wrapping up

To my ears, NAM A2 is a clear step up in sound quality. But you don't have to trust my ears; over 1000 people participated in T3K's blind listening test.

NAM A2 is a great achievement from the team at TONE3000. It will be exciting to see what industry adoption ends up being like; the technology and community behind NAM seem to have a lot of momentum.

If you haven't tried NAM out at all yet, it's a great time to check it out! It's free, both as in beer and speech. To try it in your DAW, you need to download the Gateway plugin from Neural Amp Modeler and some A2 amp models, which you can find on this site in select articles and on TONE3000's broader community.

This is also a good example of why firmware updates are so important with digital guitar gear, a topic I've covered here before.

TONE3000's full guide to A2 is a great read (I've been linking to various relevant parts of it throughout this article).

Keep playing and having fun! Thanks for reading.