Older DAC connection to my Macbook??

I would go with a USB/SPDIF converter. I have used many with older DACs. Use an Audiophileo 2 with Pure Power power supply. They come up used here on AG. Wiith the added power supply probably run ~$500-$600. In the interim you might get a Music Fidelity V-Link or M2tech Hiface converter. Either should run~$100 used and easier to find I use the Hiface in a 2nd system. 

Or just use the digital optical output on the macbook. Like @randy-11 said, the headphone output is also the toslink output. You’ll just need one of those little adapters to put on the end of the optical cable so it can attach to the ’headphone’ jack. That will be way less expensive than multi hundred dollar converters.

Thank you for the replies. The last one seems the most likely. I guess that's why those Dac prices seem to drop so much. Features and current connections are very important.

Indeed. As well as constantly advancing DAC chip technology. But there's nothing wrong with older units if the rest of your system isn't top of the line, state of the art stuff.

I have a pretty nice rig. Parasound JC-1's with JC-2 preamp. I have an Exogal Comet plus DAC and Salk Song 3 speakers. My Arcam FMJ cd 23 cd player is getting up there in age so I saw an Esoteric transport and Dac for sale on here. The Esoteric stuff is 10 years old but very expensive and highly regarded at the time of release. I keep hearing about the 'detail' of Esoteric gear so I guess i want a piece of that. I would also like SACD capability which i don't have. My system sounds pretty musical now.