IAW these specs:
Features:
- USB: 24/96 up sampling to 192 Hz
- Toslink and coaxial: 24/192Hz
- Galvanic Isolation: ADuM 1250 chips
- Asynchronous Burr Brown Chip AD1896
- DAC Chip: PCM 1798
- R Style Transformer
- State of the Art Components: ESA Clarity capacitor filters, gold plated RCA jacks
(Although this was copy pasted from your DAC maker's web site, it should be 192 kHz not 192 Hz.)
The Toslink would be a better choice because the USB would have to use up sampling to reach 192 kHz. The USB would work though. Use a USB cable from the Mac to the DAC. Then use the Mac's Audio Midi Setup to select your DAC.
The audio output jack on the Mac is a combination Line Level Analog output and a Laser Toslink digital output. You can buy Toslink cables that have a miniature phono laser plug on one end and the more standard Toslink on the other.
Or, you can buy a miniature phono to Toslink adaptor.
plus a cable
Note: If you don't have any digital source material above 96 Hz, then the USB and Toslink connection would be toss up, sic.