RME User Forum — Fireface UCX (1st gen) SPDIF output in CC mode

Re: Fireface UCX (1st gen) SPDIF output in CC mode

null@example.com (vasco.f.santos) — Tue, 26 Aug 2025 15:52:37 +0000

Thank you. I already figured this out. I had to enable the "pro-audio" profile in Pipewire/Wireplumber.

Re: Fireface UCX (1st gen) SPDIF output in CC mode

null@example.com (MC) — Tue, 26 Aug 2025 15:47:51 +0000

You need to select the Alternate Setting that allows access to all channels (the UCX has 2 and 18 channel modes). That's a Linux question, not an RME issue, and is not related to the CA and C8 feature.

Re: Fireface UCX (1st gen) SPDIF output in CC mode

null@example.com (vasco.f.santos) — Tue, 26 Aug 2025 09:02:43 +0000

I am running a Fireface UCX with Pipewire (Fedora 42).
Even in CA mode, I can't see more than the stereo ins and outs. It's like C8 but I get no playback sound at the outputs.
How do I enable the 18-in/18-out setup?

Re: Fireface UCX (1st gen) SPDIF output in CC mode

null@example.com (MC) — Fri, 22 Aug 2025 01:18:39 +0000

The playback channel routings are set in CC mode to C8 or CA. The only way to change this is using the TM FX app on the iPad. Loading setups from memory will most probably only load input to output mix and routings. So I think your obervations are correct.

Re: Fireface UCX (1st gen) SPDIF output in CC mode

null@example.com (forphew) — Thu, 21 Aug 2025 17:09:51 +0000

First of all, thank you so much! I must have enabled C8 mode by accident one day... In CA mode playback 9/10 corresponds to SPDIF as one would expect

I'm just trying to clarify a few things now so I understand it properly...
Is my understanding of these correct now?:

C8 = The mode where stuff gets duplicated (1/2 -> SPDIF, Headphones, etc.)
CA = "Normal" mode for CC, just raw access to the channels
1-6 = Stored setups on the device, configured in TotalMix

Because if I load setup 1, where I have 1/2 output to SPDIF, it doesn't seem to work. On the other hand, even in CA mode, the playback monitoring I've setup in TotalMix on Windows (playback SPDIF Input on Headphones) is working perfectly. From my understanding I would've assumed this to only work in 1-6 mode, not CA.

Thanks again for your input!

Re: Fireface UCX (1st gen) SPDIF output in CC mode

null@example.com (MC) — Thu, 21 Aug 2025 13:45:46 +0000

With C8 (or CA or setups 1 to 6) in the display selected, press the knob for a second so that the display changes to i.o. The selected state is then active. Works with setups even in CC mode.

Re: Fireface UCX (1st gen) SPDIF output in CC mode

null@example.com (forphew) — Wed, 20 Aug 2025 06:05:00 +0000

Thank you!

It also mentions CA and C8 mode there. I've read about this in multiple sources now, but don't understand how to switch between these modes.

Check if CC mode is active: CC mode is active when turning the encoder lists not only CC, but
also C8 and CA in the display.

I see these, but if i hit either of them nothing happens. There also seems to be no description anywhere on how to do this..

In CC mode, the encoder in the SU - Level menu can switch between setups 1 and 2 at any
time, alternating between entirely different configurations.

Same question here: How would I actually switch between these setups? I have a Windows System aswell to do the configuration in TotalMix in.

Re: Fireface UCX (1st gen) SPDIF output in CC mode

null@example.com (waedi) — Tue, 19 Aug 2025 19:42:09 +0000

From page 97 user manual :

TotalMix FX can transfer all current settings to the device (Options/Store Current State into
Device). There are six memory slots (Setups) available. An example

In CC mode, the encoder in the SU - Level menu can switch between setups 1 and 2 at any
time, alternating between entirely different configurations.

That means you can create a routing in Totalmix and save it into the device and later in CC-mode load it.

You have to use a computer with Windows or mac for this preparation.

Fireface UCX (1st gen) SPDIF output in CC mode

null@example.com (forphew) — Tue, 19 Aug 2025 18:12:41 +0000

Sorry in advance if I'm being stupid, but I can't figure this out...
Is there a way to use the SPDIF outs in class compliant mode?

The only thing I've got to work so far was using out 1/2, which seems to mirror to SPDIF, but unfortunately it also mirrors to 7/8 (Headphones) which makes this unusable in my specific scenario.

I'm on Linux and see 18ish (don't remember the exact number right now) outputs in qjackctl. Out 5/6 (Analogue) works fine. Just can't seem to get any SPDIF output, other than with the workaround mentioned above...

Is what I'm trying (isolated SPDIF output) even possible in CC mode?