Question and issue, Usb Card, Session and more

Patchbox OS
1

Dear all,
My goal is to realize a 4 tracks loopstation using SooperLooper with an external controller (midi or osc) and Rpi as core audio device.

I installed a fresh image of PatchBox Os and make all updates automtically at first startup.
I not installed any optional package (ModeP ecc).

I try 3 different usb audio without success.

M-Audio Fasttrack c400 - No sound at all

M-Audio Fasttrack (the cheapest with 1 xlr and 1 hiz)
Works with high latency settings and crack pop sometimes

M-Audio Fasttrack Ultra
Has direct monitoring so I ear the input without latency and can set volume with alsamixer, but the loops sound bad, with some metallic sound and strange modulate/pitching issue

I try a freash raspbian with desktop, installed jackd and sooperlooper and with the Fasttrack Ultra can get 2,9ms ol latency at 88,2khz without any audio glitch.

immagine
immagine3476Ă—1951 833 KB

I cannot understand why I cannot get work it with patchbox os…

2

With USB audio cards you should use much larger buffer size, at least 512. I’d recommend also sticking to 44100 or 48000 sampling rates.

3

I did several test and combinations and I had the same issues with larger buffer or different sample rate.
With rasbperry os (without any optimization) I can have 88,2 khz and 128 buffer without glitches.
With Patchbox the sounds on my Fasttrack Ultra are bad in any case…

4

Try switching to stock kernel using the menu in patchbox, if it’s not already.

5

Which Raspberry Pi model are you using?

I have a Pi 4 and a cheap 7$ usb stick audio device. I easily reach 48khz and 10ms buffer, even with heavy Sunvox patches. But that’s on default Raspbian. On Patchbox I had lots of issues so i stopped using it. :frowning:

That being said, I’m very interested to know about your 4 track looper, if you want to share any details!

6

Dear narF,
I’m really busy at the moment, I did some small steps.
I use Mobius Looper on Windows for years and my goal is recreate my Looper with a small and portable hardware and raspberry is a great candidate.
I have a Raspberry PI 3b+, after some test, I set the freq to 48khz with 128 and It is really stable.
I use hardware monitoring for direct input monitor without any latency and SooperLooper has a built in latency compensation for keep all synchronized.

There are many difference btw Mobius and SooperLooper. I write my own scripts for Mobius, my LoopStation model is Ed Sheeran Chewie 2. I saw a lot of live performance and try to reproduce the same behaviours. With Mobius I get it. SooperLooper is based on EDP-4 Gibson Looper and Is a bit different story. I did some test and I start to develop a layer that reads input from pedalboard (is Arduino based and I can send midi or direcly byte via usb/com serial port) and translate into OSC commands for SooperLooper for achive my “looper logic”. My small layer is in .net core becouse I’m a Windows developer :slight_smile:

1 Like