EDIT2 08:47: pls reread, additional information, structure, cosmetics

I think there are 2 solutions possible.

1) the really "cool" one: get an Octamic XTC, a preamp with multiformat I/O

Advantages of this solution:

http://www.rme-audio.de/en/products/octamic_xtc.php - It perfectly matches your setup with the UFX+ as it supports MADI and on top of that you can integrate the XTC as so called "AUX device" into your UFX+'s TM FX instance and by this:

• remote control one or more XTC
  

• route all inputs and outputs (of UFX+ and up to 8 XTCs) between each other
  

• and store all relevant setting digitally in snapshots and workspaces
  

The XTC offers 4 AES inputs and outputs that you can use, you only need to order an additional digital breakout cable
http://www.alva-audio.de/en/aes-ebu_cab … o_8_x_xlr/
There are other cables options possible, you need to look what you need in your rack.

The "cool" thing about the XTC is, that it is extremely versatile:

• It supports class compliant mode so that you can use it as recording device for an iPAD.
  

• The 8 Mic inputs can also be used as balanced line inputs when using XLR plugs.
  

• Otherwise with TRS plug you can use the 1st 4 inputs with PAD and
  

• with TS plug you can use the last 4 inputs as instrument input.
  

• It has 2 very good phones outputs that you get on top.
  

• And it has one ADAT input and 2 ADAT outputs.
  

• You can use it even as format converter.
  

2) the cheapest solution - Digiface USB

If you connect the UFX+ via USB then you use the MADIface driver.
In this case it would be easiest to get a Digiface USB on top which uses the same driver.
Then the DAW can access both devices in parallel as they use the same ASIO driver.

You only need to use 1 ADAT port for digital synchronization between the 2 devices. Clocking: UFX+ is master, 1 TOSLINK cable from UFX+ ADAT1 OUT to i.e. Digiface USB ADAT1 IN, Digiface gets clock from ADAT1 IN.

You also need to make sure in the MADIface ASIO driver settings to always use the same ASIO buffersize for both devices.

Advantages of this solution:
- price
- the Digiface USB is the only RME device where you can change all (4!) ADAT ports to support optical SPDIF !!

Disadvantages of this solution:
- you need to use 2 TM FX instances
- you can not route between ports of 2 different TM FX instances
- you need a 2nd USB port, maybe minor, but I want to mention it

MADI - Required Cabling

Best take OM4 cabling which is also being used in the networking area:
Duplex Jumper SC-SC 50/125µ, OM4: https://www.reichelt.de/duplex-jumper-s … H=OM4&

Blog article about UFX+ and 2 Octamic XTC via MADI incl. config

In this blog article (german only sorry) you find the required configuration for MADI and AUX device, so this should be easily understandable simply in terms of the configuration: https://www.tonstudio-forum.de/blog/ind … Cber-MADI/

My recommendation

As you took already the right decision to get the UFX+ to be able to easily expand your solution by MADI, then I think it would make sense to go for one Octamic XTC.

The XTC gives you a lot of different ports and you can remote control and route everything inside of the one TM FX instance.

MADI gives you the flexibility of using optical fiber cable (up to 2km length), so you can place the OctaMic XTC also easily into a separate recording room in the building.

The MIDI over MADI feature saves you additional MIDI cabling to remote control Octamic XTC.