USB Soundcard to Pisound output

Patchbox OS
#1

Hi,

I have a probably simple question: I want to use my OP-Z (Synth), which is connected via USB to Pisound as Sound Input, and want to send the incoming sound via the Pisound Output.
OP-Z has a built in Soundcard, thats why its possible to send its Sound via USB.

I have the newest Patchbox OS. I tried it with via Jack Settings, but couldn’t find the solution.
Ideally it should send the sound directly to the output, but I can also Monitor it via Audacity.
Basically the question is, different sound source -> pisound output.
Is that possible?
Thank you!

#2

Hey, Jack backend by default only works with a single audio interface. There’s a way however to make other card’s ports appear, check out these links:

Try to run alsa_in from a terminal:

alsa_in -j "OP-Z" -d hw:2,0

The -j just sets the display name for Jack backend, -d specifies the hardware ID, I’m just guessing it’d be hw:2,0, but you may check using arecord -l. Further options are available to be set to control more audio parameters.

As long as this command is running successfully, the audio ports should appear in Patchage / jack backend, and should be routable.

#3

Thanks a lot for getting back, though
I think it doesn’t work, I got this message, and it doesn’t go further :confused:

patch@patchbox:~ $ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: pisound [pisound], device 0: PS-0Z7FE7V snd-soc-dummy-dai-0 []
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 2: OPZ [OP-Z], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

patch@patchbox:~ $ alsa_in -j "OP-Z" -d hw:2,0
WARNING: Rate doesn't match (requested 48000Hz, get 44100Hz)
WARNING: buffer size does not match: (requested 2048, got 1882)
WARNING: period size does not match: (requested 1024, got 941)
selected sample format: 24bit - real
delay = 4616
delay = 122
#4

These are just warnings - as OP-Z does not provide 48kHz stream, it must be resampled in software, this uses some CPU, there’s some quality control settings to control it.

After this is running, you should see OP-Z in patchage, and should be able to route it as needed.

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#5

May I add a couple of questions that I think are a bit related.
I have:

  • Sonuus I2M musicport (usb class compliant), that is just a 1,4" mono Hi-Z input (but no output).
  • Source Audio Soleman (usb class compliant), a midi footcontroller.

Since both are usb class compliant I’m guessing that both can be connected to my RPi4 while I also have my PiSound installed?

#6

You should be able to use their MIDI capabilities easily, getting audio to work could be a bit trickier, as it requires either to run special utilities to get the devices into the shared Jack backend, or they could just run their own dedicated audio software, but wouldn’t be able to interact with other audio cards internally.

#7

Yeah, thanks. Figured that it probably would be like you said regarding audio. However, I’m beginning to realize that the I2M might be ill-fitted for the setup I imagine in my head. Would need a hardware audio output from it too…

Crap.

#8

Searching brought me here. I have a USB class compliant audio device plugged into pi 4 with pisound. I can see it listed in arecord -l and running alsa_in -j "MKII" -d hw:3,0

shows
selected sample format: 32bit delay = 2669

But then how do I route this audio so that I can use it as in input for my MODEP pedal board?

#9

Last time I checked modep had issues recognizing capture devices loaded through alsa_in or zita_a2j.
You can still route it manually either through patchage or jack_lsp / jack_connect.

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