Hi stephen, Welcome. Glad you finally made it here.
I believe my MBP only only sends optical S/PDIF through the headphone jack. Is your Apollo a Twin or a rack-mount?
I have the SF Apollo Quad rack-mount, and its ADAT is optical of course, but the only S/PDIF I/O it can accept is coaxial. On the other hand, the Twin's ADAT is optical, and can accept an optical S/PDIF instead of the ADAT.
If your Apollo is a Twin, it should work. If your Apollo is a rack-mount, then you probably need an optical-to-coaxial S/PDIF adapter, unless there is a way to makd the MBP output an ADAT signal.
Let's see in anyone can back me up on this.
EDIT: I just looked at a photo of the back of an Apollo 8 and and Apollo 8p. The 8 has coaxial S/PDIF connectors, but there are not any S/PFIF connectors on the 8p. I wonder if an 8p can accept an optical S/PDIF through one of its ADAT ports?
Then to the manuals...
In the Apollo 8p manual: "Lightpipe I/O can be switched to S/PDIF optical with sample rate conversion"
In the Apollo 8 manual is this: "Two channels coaxial S/PDIF I/O with sample rate conversion"
In the Apollo SF is this: "The S/PDIF ports provide two channels of digital I/O with resolutions up to 24-bit at 192 kHz via female phono (RCA) connectors. For optimum results, use only high-quality 75-ohm cables specifically designed for S/PDIF digital audio."
In the Twin manual is this: "Two channels S/PDIF optical with sample rate conversion"