Denafrips Ares DAC has arrived... need help with Oppo connectivity

Interesting you heard no difference. I've never heard two dac's that sound exactly the same. I've tried a few, including the Ares. I would suspect something is amiss in your setup, or  a shortcoming somewhere in your system that doesn't reveal the difference.

Stfroth and 4hannons
I agree, it does seem odd.  No sonic difference when trying 4 different DACs with my Oppo.  I did go in and upgrade the settings on my Oppo as described on page 61 and 62 of the Oppo manual. Still, I can't discern any difference after the setting changes.  With an excellent Don Sachs tube preamp, a Pass Labs amp, Spatial Audio M4 TS speakers, Cerious Technology power and IC cables, and Supra wire to my speakers, I am not sure where the shortcoming would be in my system.  It might be my 64 year old ears, but much younger ears fail to hear any difference either.  Still, it seems logical that I would hear some perceptible difference in SQ, but I hear none.  

Stforth,
I had Don Sachs upgrade all my Harman Kardon Citation gear (I, II, and V), but his preamp is vastly better than the upgraded C-I.  Don is a genius with both his tube preamp, based on 6SN7 tubes, and his KT88-based amp.  In my experience, his tube gear gives one a glimpse of high-end sound at a fraction of the cost of major audio companies.   Send me a PM and I will be happy to chat with you about the preamp.  

I have fooled around with a boatload of modestly-priced cables, but really like the Cerious Technology graphene cables, followed by Silnote and Shunyata.   I could hear more difference in SQ swapping the various IC's and power cords than I have with the 4 DACs I have auditioned.  Cheers, Mark