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A low latency guitar effects processor suitable for running on a Raspberry Pi

github.com

11–20 of 147 posts

Re: A low latency guitar effects processor suitable for running on a Raspberry Pi

#11

I thought is hard to have low latency audio in Linux with stuff like PulseAudio.

Possible with jackd etc

I switched to BSD and got much better latency on the same hardware

But I think that was the alsa -> BSD oss driver swap, which is possible on linux too. I had just never tried it, since I assumed linux was best

(I'm only sharing this cus i think its interesting, and may help you get good latency)

Re: A low latency guitar effects processor suitable for running on a Raspberry Pi

#12

I thought is hard to have low latency audio in Linux with stuff like PulseAudio.

The RTAudio tools this is based on allows different backends to be configured. I guess you could use Alsa or Jack if you want...

https://github.com/thestk/rtaudio/blob/master/install.txt

Re: A low latency guitar effects processor suitable for running on a Raspberry Pi

#13

I thought is hard to have low latency audio in Linux with stuff like PulseAudio.

Jack offers the low latency necessary for music production.

Pipewire is supposed to offer low latency as well - at least lower than Pulseaudio, but I don't know how much.

Re: A low latency guitar effects processor suitable for running on a Raspberry Pi

#14

I thought is hard to have low latency audio in Linux with stuff like PulseAudio.

Nah, low latency audio is absolutely possible, but not necessarily using pulse audio. Using either Jack for the low latency stuff has been the advice for years, but with the advent of pipewire you can mix and match without too much difficulty.

A quick skim didn't turn up what audio backend this project is using, but I'm using patchbox with modep on my Pi4 as a bass pedal board and it's pretty much flawless low latency. I do need to add a fan to my pi since it's mounted underneath a pedal board and doesn't get quite enough air though.

Re: A low latency guitar effects processor suitable for running on a Raspberry Pi

#16
post #8

> Note that since the server program exposes an HTTP server you can actually navigate to the IP address of your PI from any device connected to the same wifi and control your pedal chain from there. That's a killer feature for me, hiding at the end of the README. I have a Fractal Audio FM3[0] at home, and the only way I edit my patches is using their editing software over a USB connection to the device. Adding the ab…

Always hear about the Fractal Axe FXIII--seems like the gold standard in guitar FX. Didn't realize they had smaller, non-rack-mount form factor devices. Very interested in trying out the FM3 now that you brought it to my attention. Thanks!!

The Mod Dwarf (and its predecessors) also allows web control and it supports standard LV2 plugins :)

https://mod.audio/dwarf/

https://wiki.mod.audio/wiki/LV2

Re: A low latency guitar effects processor suitable for running on a Raspberry Pi

#17

I thought is hard to have low latency audio in Linux with stuff like PulseAudio.

Possible with jackd etc I switched to BSD and got much better latency on the same hardware But I think that was the alsa -> BSD oss driver swap, which is possible on linux too. I had just never tried it, since I assumed linux was best (I'm only sharing this cus i think its interesting, and may help you get good latency)

I'm enjoying the downvotes :)

Was anything I said wrong?

Seriously, I've spent a long time fixing up low latency audio

jackd + OSS on whatever OS u like is not bad advice fyi

Re: A low latency guitar effects processor suitable for running on a Raspberry Pi

#18
I'm still patiently waiting for future digital mixing consoles to do all processing in software on inexpensive x86 or ARM processors. Currently due to latency and reliability requirements all DSP work is done on dedicated chips or FPGA which brings up the BOM and engineering cost. They often have a small ARM/Linux module which is used for the displays and network control.

The CPU tech is here today, and modern general purpose processors do a good job of handling low-latency audio. Someone just needs to put all that together in a unified and stable package...

Re: A low latency guitar effects processor suitable for running on a Raspberry Pi

#19

I thought is hard to have low latency audio in Linux with stuff like PulseAudio.

Possible with jackd etc I switched to BSD and got much better latency on the same hardware But I think that was the alsa -> BSD oss driver swap, which is possible on linux too. I had just never tried it, since I assumed linux was best (I'm only sharing this cus i think its interesting, and may help you get good latency)

BSD has in-kernel audio mixing, IIRC.

Re: A low latency guitar effects processor suitable for running on a Raspberry Pi

#20

Earlier quoted context omitted.

Possible with jackd etc I switched to BSD and got much better latency on the same hardware But I think that was the alsa -> BSD oss driver swap, which is possible on linux too. I had just never tried it, since I assumed linux was best (I'm only sharing this cus i think its interesting, and may help you get good latency)

I'm enjoying the downvotes :) Was anything I said wrong? Seriously, I've spent a long time fixing up low latency audio jackd + OSS on whatever OS u like is not bad advice fyi

I honestly have no idea.

Personally I'm very happy to see that info as I do use both Linux and *BSD and wouldn't have ever tried setting up BSD for audio until now.

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