• Registered: 2024-01-10
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Topic: RME Ufx 2 - Connecting a Kemper Amp (Spdf Coax to Spdf Toslink)

I have own the RME UFX II audio interface and a Kemper amp. I would like to connect the two together digitally - but I am a total beginner in regards to S/PDIF.

The Kemper has S/PDIF Coax (looks like cinch) in and out, but the RME only has S/PDIF optical (I think it's called toslink?) in and out. There seem to excist devices that convert it. The Audio Converter S/PDIF product description it says: "Digitally converts digital optical Toslink to electrical coaxial S/PDIF signals and vice versa".
This solution should work, right? And should be the "cleanest" way to connect both? (all stays digital, no unnecessary A/D conversions)
Since someone wrote on the forum that he tried S/PDIF on the Kemper and to his ears it "sounded worse" than to use the Kemper analog out RME analog in route, but it shouldn't?

Is there anything else I should look out for when I try to connect the two?

Thanks a lot from Hamburg

  • ramses
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Re: RME Ufx 2 - Connecting a Kemper Amp (Spdf Coax to Spdf Toslink)

Check manual. AES port can be switched to SPDIF protocol and the manual shows you pinout for an AES to SPDIF cable.
But tbh, you can also use an analog cable as well. There will be not much (zero?) difference and you do not have to take care about clock synch.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

3 Reply by Metalfan (edited by Metalfan 2024-01-10 17:25:24)

  • Registered: 2024-01-10
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Re: RME Ufx 2 - Connecting a Kemper Amp (Spdf Coax to Spdf Toslink)

Thanks for the info!
"AES port can be switched to SPDIF protocol" Hm, in my options I can only switch to AES/SPDF and the port is just called "optical 2"?
(would have loved to share a screenshot here, but it didn't work)

"the manual shows you pinout for an AES to SPDIF cable" - AES to SPDF? Sounds complicated. Does this mean a simple SPDIF cable would not work?

"you can also use an analog cable as well." Well, I would prefere not to, since I already used up all the line inputs/outputs on the back of the unit and don't want to use the front inserts for a permanent remaining connection (have so many cables lying around in my small room). Maybe I will buy another Adat Preamp unit later on and use the analog inserts there, but I would love to try the digital route first.

  • Registered: 2024-01-10
  • Posts: 4

Re: RME Ufx 2 - Connecting a Kemper Amp (Spdf Coax to Spdf Toslink)

So just read the manual and the inputs/outputs and the AES thing seem to be compatible with SPDF, if the setting "consumer" is chosen.

Here the parts:
"The digital outputs of the Fireface UFX II provide AES/EBU (SPDIF compatible) and ADAT optical signals at the corresponding ports.
Optical 2 In: Operates as second ADAT input (default). Selecting AES/SPDIF will route the optical input signal to the AES-Receiver.
Optical 2 Out: This optical TOSLINK output can also operate as ADAT or SPDIF output."

"AES Format
The AES output signal can have the Channel Status Professional or Consumer (SPDIF). This setting is also valid when ADAT2 has been set as AES/SPDIF output."

  • ramses
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Re: RME Ufx 2 - Connecting a Kemper Amp (Spdf Coax to Spdf Toslink)

exactly and then a digital adapter cable
https://www.thomann.de/de/pro_snake_aes … male_3.htm

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

6 Reply by MC

  • MC
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Re: RME Ufx 2 - Connecting a Kemper Amp (Spdf Coax to Spdf Toslink)

You should update to the latest firmware and drivers to enjoy a better SPDIF functionality on your UFX II:

https://forum.rme-audio.de/viewtopic.php?id=38691

Updated manual comes today.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2023-04-05
  • Posts: 5

Re: RME Ufx 2 - Connecting a Kemper Amp (Spdf Coax to Spdf Toslink)

I've been using my Kemper with the UFX2 for a couple of years now.
You can follow the instructions in the RME manual and build cables to connect the spdif coaxial to the  AES/EBU ports of the interface. If you're not into soldering your own cables, you can also go with getting the cables from Thomann as mentioned above wink

  • Registered: 2024-01-10
  • Posts: 4

Re: RME Ufx 2 - Connecting a Kemper Amp (Spdf Coax to Spdf Toslink)

Okay, thanks everyone! I got it working. :-)

As a novice I was very confused in the beginning, since there are two ways to connect SPDF.
A) Either optical via the Adat slot and then switch the Adat 2 settings to Aes/SPDF (for this a >50 € conversion device would be needed in case of the Kemper since it has only coax out).
B) The other, better option in my case, was to use those XLR locking slots via AES/Ebu (where the mentioned 15 € Thoman Cable was necessary) and then use the appropriate settings in the RME MadiFace settings.

In the beginning I didn't understand that those where two seperate options and tried a mixture of both.
But know I learned something new and it sounds great.
Thanks!