The Macintosh also has an optical output, most likely SPDIF, can you check that in the manual?
Then the Macintosh phone preamp would do the A/D conversion, which should be ok according to the price.
In a good case of luck you could save a lot of money, e.g., if your Mac also has a digital SPDIF input
then you can connect it directly to your Mac using a TOSLINK cable (if this is an optical SPDIF port).
You could also use an RME recording interface like the Digiface USB with 4x ADAT I/O if you would rather not spend that much money for an ADI-2 Pro.
But if you intend to use the ADI-2 Pro, and its unique features (Auto Ref Level, dynamic loudness, excellent headphone preamp) then go for the ADI-2 Pro FS R BE.
If it is an older Mac, I would check whether the macOS version is supported by the RME drivers for either ADI-2 Pro or Digiface USB.
@KaiS: using an ADI-2 FS is maybe not feasible here or the best possible solution as it has no USB interface towards PC, and currently it is not clear what I/O ports are available on the Mac. I fear some tiny analog plugs, if any, I wouldn't use them in such a setup.
I would digitize the signal as early as possible, either on the Macintosh phono preamp and the SPDIF connection to Apple.
Or by using the ADI-2 Pro FS R BE for A/D conversion and then via USB to the Apple computer.
UFX+, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1650v4, Win10Pro22H2, Cub12Pro