AudioNoise README

The project's README from github.com/torvalds/AudioNoise. As one markdown file: README.md.

The digital RP2354 and TAC5112-based guitar pedal actually does work, even if I'm not thrilled about some of my analog interface choices (ie the pots in particular, and I'm growing to hate the clicky footswitch even if I do love how it also doubles as a boot selector switch for programming).

But while the hardware design is archived while I ponder the mysteries of life and physical user interfaces, I'm still looking at the digital effects on the side. But right now purely in a "since it's all digital, let's simulate it and not worry about the hardware so much".

These are -- like the analog circuits that started my journey -- toy effects that you shouldn't take seriously. The main design goal has been to learn about digital audio processing basics. Exactly like the guitar pedal was about learning about the hardware side.

So no fancy FFT-based vocoders or anything like that, just IIR filters and basic delay loops. Everything is "single sample in, single sample out with no latency". The sample may be stored in a delay loop to be looked up later (for eacho effects), but it's not doing any real processing.

I was happy with how the TAC5112 had sub-ms latencies for feeding through the ADC->DAC chain, and this is meant to continue exactly that kind of thing. Plus it's not like I've done any of this before, so it's all very basic and simple just by virtue of me being a newbie.

Put another way: the IIR filters aren't the fancy AI "emulate a cab" kind of a modern pedal or guitar amp. No, while they do emulate analog circuits like a phaser, they do so by emulating the effects of a RC network with just a digital all-pass filter, not by doing anything actually clever.

Also note that the python visualizer tool has been basically written by vibe-coding. I know more about analog filters -- and that's not saying much -- than I do about python. It started out as my typical "google and do the monkey-see-monkey-do" kind of programming, but then I cut out the middle-man -- me -- and just used Google Antigravity to do the audio sample visualizer.

AudioNoise (torvalds/AudioNoise)

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What is this?AudioNoise is a small, playful collection of digital audio effect simulations (phaser-like all-pass filters, delay-based echoes, etc.) written in C by Linus Torvalds as a side project for learning digital signal processing basics, originally tied to his DIY guitar-pedal hardware.
Is this the actual guitar-pedal hardware code, or just a software simulator?It is a pure software simulation of the effects; the physical RP2354/TAC5112 guitar-pedal hardware project is a separate, currently archived effort, and this repo just models the same digital processing on its own.
How do I build and run the effects?The repo ships with a Makefile, so you build with 'make'; beyond that, the README doesn't walk through specific usage steps.
Do I need anything beyond a C compiler to try this out?A C toolchain and make are enough to build the effect code itself; there's also a separate Python-based visualizer tool for inspecting the audio samples.
Are these anything like modern amp-sim or cab-emulation effects?No — these are intentionally simple toy effects using only IIR filters and basic delay loops with no latency, not fancy FFT-based processing or AI-style amp/cab modeling, and the author explicitly says not to take them seriously.
Why build digital simulations instead of finishing the hardware pedal?The author wanted to keep exploring digital effects while the physical guitar-pedal hardware design is paused, so simulating everything in software lets the learning continue without needing the actual board.
What does the Python visualizer tool do?It's a separate helper for visualizing the audio samples/effects; the author admits it was largely built via vibe-coding with Google Antigravity rather than hand-written Python expertise.
Does the audio processing add any noticeable latency?No — every effect is designed as single-sample-in, single-sample-out with no added latency, mirroring the sub-millisecond ADC-to-DAC latency the author achieved on the real TAC5112 hardware.
Creator
torvalds
Size
1.4 MB
Stars
4.5K
Updated
CommitMay 08
Age
9mo
Commits · 90 Days