The PSA DL III is a great piece of gear and can vastly improve most CDPs. Since the Yamaha is reliable, the DLIII will reclock the signal, the sound is very pleasing and 3 dimensional. The only issue is the future where we may see very wide bandwidth output from players. There are some DACs that take 192k, like the Benchmark, which I have not heard but is well reviewed. I suspect there is a difference in the sound and one may be more to your liking. I can only tell you what I like and the DLIII works superbly for me.
Marantz CD5003 or PS Audio Digital Link III
I'm thinking about getting a new CDP since my Yamaha is 15 years old. I've been using it as a transport for 13 years with a Audio Alchemy DDE V1.1 dac. The Yamaha is built like a tank and is dead quite. My question is should I splurge for a Digital Link III or should I just go with the stand alone Marantz? By the way, the Yamaha only has optical output. Any thoughts would be appreciated.