What do you want to connect?
Are you aware of, that one AES ports supports two channels (for stereo)?
Do you really need a 2nd AES port or only an AES splitter e.g. to connect a 2nd active monitor?

Hi Jack,

the optional OPTO-X card is a ** replacement ** for the daughter card to get a third optical MADI port.
The AES port is on this daughter card, so at the end of the day, you will have one AES port, not more.
The product is also only advertised with an AES port.

Without looking at the manual I assume, that the M-1610 Pro has the same flexibility in terms of routing like all other MADI/AVB products, but pls check yourself by reading the manual or by asking RME.

IMHO it should be possible to route analog inputs or audio from MADI or AVB to the ADAT outputs.
But only ADAT is supported as a protocol. So you need to check what device you want to connect here, whether it supports ADAT, some products only support SPDIF.

If you should have an Octamic XTC somewhere or get one from used market .. it has 4x AES I/O.
You also need the breakout cable if you would like to get one.

I am a customer like you, I have no further information.

If I look at the suggestions above, a format converter costs a lot of money and the device does nothing else than the name says, convert from one format to the other, e.g. ADAT<-->AES.

Therefore, I think you might be interested in the following suggestion.

You could also get another AES port using the ADI-2 Pro FS R BE, which in digital through mode also can convert from ADAT to AES.

You would not only have invested money in a format converter, but also in a powerful product that can enhance your monitoring section with some unique and very respectable features.

Then you could perhaps route the analog output of all three DACs to your active monitors via a kind of monitor controller or passive switcher and then select different DACs for the output as desired.

I'm not sure if this setup really fits 100%, but I think it's enough to get the idea across that you might be better off investing the money in an ADI-2 Pro FS R BE. And then doing the format conversion through that.

Here some additional information that could wake your interest to invest into the ADI-2 Pro FS R BE.
Even the former model ADI-2 Pro FS did already very well in this "Mastering Converter Shootout" on YouTube from Marc Einstmann:
https://www.youtube.com/watch?v=doHG32aXBDY
There, the ADI-2 Pro FS (former model) was compared against Crane Song HEDD-192 and AD122.
Marc Einstmann uses the different converters in his setup depending on which one supports the music material best.

Here some information from the manual about digital through mode of the ADI-2 Pro FS R BE:

A connection schema for your setup, how I understood it (hopefully well enough).

PC---USB---ARC USB
|  \---USB2-------------------------------------------------+ for remote controlling ADI-2 Pro using ADI-2 Remote
|                                                                             | or as an option to playback DSD content using a different profile
| PCIe                                                                    |
HDSPe MADI FX---AES---------->AES---DAC#1---ANALOG----------------------------------------+
|    |                  \---AES<----------AES---/                |                                                               \
|    |                                                                       |                                                                \
|    + M-1610 Pro---ADAT------>ADAT---ADI-2 Pro FS R BE---AES---->AES---Burl---ANA---->Monitor Contr.--->Act. Monitors
|    |                     \---ADAT<-----ADAT---/             \   \        \---AES<-----AES---/                        /
|    |                                                                     \   \                                                            /
+--+                                                                      \  +-AN1/2-------------------------------------+
MADI                                                                      +---AN3/4------------------------------------------------------------>Phones Out

PC---USB---ARC USB
|  \---USB2----------------------------------------+ for remote controlling ADI-2 Pro using ADI-2 Remote
|                                                                   | or as an option to playback DSD content using a different profile
| USB3                                                          |
UFX III---AES---------->AES---DAC#1---ANALOG------------------------------------------+
    \ \   \---AES<----------AES---/                      |                                                          \
     \  \                                                            |                                                           \
      \  +--ADAT---------->ADAT---ADI-2 Pro FS R BE---AES---->AES---Burl---ANA---->Monitor Controller----------->Act. Monitors
        +ADAT<-------------ADAT---/             \   \        \---AES<-----AES---/                        / (or also smth like Manley Backbone
                                                               \   \                                                            /  in the video for analog summing)
                                                                  \  +-AN1/2------------------------------------+
                                                                   +---AN3/4------------------------------------------------------------------------->Phones Out

Advantages of UFX III
- analog ports as you mentioned (with converter of ADI-2 Pro FS reference converter)
- ROOM EQ for room correction
- also an FX section just in case you need it occasionally for special purposes
- still one MADI bus if you need to connect further devices
- MADI ports also useful to use spare ports for creating Submixes for loopback recording

and if you should also record something from time to time
- four superb Mic Pre's with AUTOSET which do a fantastic job when being used as Instr input
- DURec for backup recordings if you should be recording