• Registered: 2023-11-08
  • Posts: 2

Topic: Record SPDIF in Reaper on Fedora 38

Hi folks,

I just got a Fireface UCX II and have a particular use case which I cannot get to work. I am completely new to RME interfaces so, please forgive if I may have overlooked something really obvious.

I have an external SPDIF device hooked up to the UCX II, which I want to record into Reaper. I am working on Fedora 38 in class compliant mode (obviously). The UCX II shows up in qpwgraph as an audio device with 8 input channels. From my testing, these channels seem to correspond to the analog mic pre's and line/instrument ins of the UCX II. As I said however, I want to be able to record the SPDIF In. Is there any way to assign the SPDIF In to one of the 8 input channels in the front panel settings?

Thanks for your suggestions.

2 Reply by waedi (edited by waedi 2023-11-09 01:13:41)

  • waedi
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  • From: Swiss Zürich
  • Registered: 2020-12-08
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Re: Record SPDIF in Reaper on Fedora 38

The qpw shows you an incorrect thing, it probably is not able to show more than 8 channels or is by default in 8-channel layout. Can you change it ?
The UCX ll has 20 input and 20 output channels, the SPDIF is fix two of them.
Have you done this :
Now with stack (bottom to top):
ALSA / Pipewire / Wireplumber / qPwGraph / Reaper

M1-Sonoma, Madiface Pro, Digiface USB, Babyface silver and blue

3 Reply by MC

  • MC
  • MC
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Re: Record SPDIF in Reaper on Fedora 38

Are you in CC mode? Then the CC Mix mode 8 Ch. might be active. See manual chapter 36.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2023-11-08
  • Posts: 2

Re: Record SPDIF in Reaper on Fedora 38

MC wrote:

Are you in CC mode? Then the CC Mix mode 8 Ch. might be active. See manual chapter 36.

Yes, CC Mode is on with CC Mix 20 Ch. Playback.


The qpw shows you an incorrect thing, it probably is not able to show more than 8 channels or is by default in 8-channel layout. Can you change it ?
The UCX ll has 20 input and 20 output channels, the SPDIF is fix two of them.
Have you done this :
Now with stack (bottom to top):
ALSA / Pipewire / Wireplumber / qPwGraph / Reaper

I found the solution to my issue. Pipewire, the audio subsystem on current Linux distro's has 2 default profiles ("consumer" and pro) for audio devices. The UCX II was running with the "consumer" profile which handles a maximum of 8 channels. I switched the profile to pro with the pavucontrol tool and now the UCX II shows up as 20 input + 20 output device.

Recording Spdif works like a charm now smile

For more info, you can check the following sources:

Thanks!