1 Topic by dazza_devil7 (edited by dazza_devil7 2023-05-28 01:46:35)

  • Registered: 2022-09-08
  • Posts: 17

Topic: Connecting UA OX Amp Top Box to UCX II

I'm thinking about getting a Universal Audio OX Amp Top Box to use for recording my 100W combo tube amp and want to know the best way to connect it to my UCX II for this purpose. The OX box has two digital outputs, a stereo S/PDIF digital output jack that accepts a 75-ohm coaxial RCA digital audio cable and a stereo S/PDIF digital output port that accepts a TOSLINK optical cable. The later port outputs S/PDIF format only and is incompatible with ADAT optical inputs. Would I be able to connect the OX through TOSLINK to the optical ADAT input on my UCX II and if so how would I set this up in TM FX? If I were to use the digital breakout cable and connect through the AES/EBU & SPDIF would I need to purchase an  RCA/XLR cable adapter and if so would any RCA/XLR cable adapter be sufficient or would I need a specific adaptor as outlined in the manual where pins 2 and 3 of a male XLR plug are connected individually to the two pins of a RCA plug and the cable shielding is only connected to pin 1 of the XLR, not to the RCA plug?
Another question, would I be better off to connect the OX Box to the UCX II through analogue output using balanced TRS to XLR connections rather than digital and what are the pros and cons of each?

  • Registered: 2016-06-14
  • Posts: 1,142

Re: Connecting UA OX Amp Top Box to UCX II

Hi
To my knowledge the breakout cable for the UCX II has also RCA (chinch) plugs for coax SPDIF I/O connections, so why you consider a RCA-XLR cable?
The optical ports on the UCX II can also be used for SPDIF signals, not only ADAT.
That means, you can choose between coax and optical.
The signals then appear on the SPDIF input channels in Totalmix and also in your recording app (DAW).
I don’t know the UA OX Amp Box, but if there is a digital amp simulation processing, you would avoid additional conversion when using the SPDIF connection.

UCX - FF 400 - Babyface pro - Digiface USB - ADI-2 (original)
Mac mini M1 - Macbook pro - iPad Air2
  • Registered: 2022-09-08
  • Posts: 17

Re: Connecting UA OX Amp Top Box to UCX II

oli77sch wrote:

Hi
To my knowledge the breakout cable for the UCX II has also RCA (chinch) plugs for coax SPDIF I/O connections, so why you consider a RCA-XLR cable?
The optical ports on the UCX II can also be used for SPDIF signals, not only ADAT.
That means, you can choose between coax and optical.
The signals then appear on the SPDIF input channels in Totalmix and also in your recording app (DAW).
I don’t know the UA OX Amp Box, but if there is a digital amp simulation processing, you would avoid additional conversion when using the SPDIF connection.

Thank you for the informative reply. I have misunderstood the UCX II manual and not realised that the RCA connections on the breakout cable are usable for SPDIF digital input.
Since the TOSLINK ADAT input can also be used for SPDIF input I think this will be the best way to connect the OX Box but it is good to have options.
From what I have found in the OX Box manual I think you are correct in preferring the SPDIF over analogue connection to obtain the purest signal path by reducing D/A and A/D conversions.

  • Registered: 2019-10-01
  • Posts: 675

Re: Connecting UA OX Amp Top Box to UCX II

Hello!

Also, keep in mind that you should set the Ox as Clock Master and the UCX II as Clock Slave,
by selecting "SPDIF" or "Optical" in the 'Clock Source' Option of the UCX II 's Driver Settings!

RME Gear: Digiface USB, HDSP 9632
  • Registered: 2022-09-08
  • Posts: 17

Re: Connecting UA OX Amp Top Box to UCX II

MetalHeadKeys wrote:

Hello!

Also, keep in mind that you should set the Ox as Clock Master and the UCX II as Clock Slave,
by selecting "SPDIF" or "Optical" in the 'Clock Source' Option of the UCX II 's Driver Settings!

Very helpful, thank you.