Thank you for the quick response KaiS. Is it possible to loopback 1/2 to 3/4 phones on the ADI-2 Pro? I use my AKG K702's a lot since my wife and I just had a baby recently. Monitors are turned off for the time being.

Or should I just plug my phones into Phones 1/2?

For the phones PH 1/2 will do the job.
With:
SETUP / Options / Phones / Mute v. TRS 1/2 “On”,
you can make ADI-2 Pro mute the rear XLR’s and load a complete separated configuration when plugging headphones into PH 1/2.

Have a look at the various “Modes” that define ADI-2 Pro’s configuration, manual page 36 ff.

Select a “Mode” that fits your routing demands.
The block diagrams clearly show what’s possible.

EDIT:
After going though your postings again and having a look into the Ferrofish and Apogee converters:

It’s all about selecting a fitting “Mode” in ADI-2 Pro.
AD/DA Converter–Mode should be the one, see manual page 38.

You can have Analog In going to Optical (ADAT) Out, and Optical (ADAT) In can be selected for monitoring on XLR or Phones 1/2, and Phones 3/4 too.

Then using Ableton’s input 25/26 for recording of the analog summed signal, and output 25/26 for monitoring, should work with a straight 1:1 routing in TotalMix.

If you don’t want to sacrifice 8 DA-channels for connection of ADI-2 Pro, an inexpensive ADAT Optical Splitter could supply the channels 25-32 to the Appogee DA, while feeding the same to ADI-2 Pro.

https://appsys.ch/en/products/adat-spli … /ads-8#buy

The image doesn‘t load here, but I hope my edited post helps you further..

I see.

You‘re missing a digital path to ADI-2 Pro for monitoring directly from the PC / Ableton.

This is why I suggested the ADAT Optical Splitter to feed both the multichannel DA and ADI-2 Pro at the same time.

Might be best to use PC / Ableton out 1/2 instead of 25/26, as this is what Windows probably uses für system-wide sounds too.

TotalMix would simply run 1:1 feed-through.

Let my try to steer you through the configuration step by step.
And thanx for your offer, this advice comes for free.
If we ever meet I’ll come back to it

First try one single change:
• Set: Setup / Options / SPDIF/Remap Keys / Optical Out: “ADAT”
Do you get a signal now?

If not let’s run all through.

• Remove any possibly connected USB-cable.
USB can block changing some mode settings.

• Remove all digital cables from ADI-2, except the 2 optical ones.

• Check the optical cables, each In goes to Out.
Do yo see the red light on both?

• Reset ADI-2 to factory default to have a clean starting point:
Push and hold VOL button (NOT Volume Dial) and Encoder 1 while powering up, until you see a confirmation screen “Reset done”.
EQ Presets and stored user setups are not deleted by this.

• Set: Setup / Options / Device Mode/DSD / Basic Mode: “AD/DA”.
(Manual page 38).

• Set: Setup / Options / Device Mode/DSD / Dig. Out Source: “Default” .(should be there already) (Manual page 38).

• Set: Setup / Clock / Clock Source: “SPDIF”.

• Set: Setup / Options / SPDIF/Remap Keys / SPDIF In: “Optical”.

• Set: Setup / Options / SPDIF/Remap Keys / SRC: “OFF”.

• Set: Setup / Options / SPDIF/Remap Keys / Optical Out: “ADAT”.

• Set: I/O / Main Output 1/2 / Settings / Source: “SPDIF” (to monitor signals from Ableton on your speakers).

• Set: I/O / Phones Out 3/4 / Settings / Source: “Analog” (to check if “Analog” really gets a signal, plug your headphones into PH3/4).

TOTALMIX:
Reset to factory default, or route channels 1 and 2 straight through, for both ins and outs.
Hit “X” to see the matrix, the 0 dB level boxes should look like a straight diagonal, every input is routed to it’s same numbered output.
Here’s a collection of video tutorials about it, the 1st one covers this:
https://www.rme-audio.de/de_totalmix-fx.html

Something like the picture on the bottom.

Now:
you should see the 1/2 input meters of Totalmix show your signal,
and you should be able to record the signal from input 1/2 in Ableton,
and route it to ADI-2 for monitoring.

I’m not familiar with Ableton, so ... no further advice how to configure and route signal in Ableton.