Add an external DAC. Make my Oppo UDP-205 a true top player

I had the local "Best Ear" over to advise me on an amp I was trying.
My source was the Oppo 205. His comment was " I think the source
is holding you back".  
I am unsure if it is the DAC or the Player itself. I plan to borrow a better
DAC and see if that does it.
Maybe someone else has experience here?

I also had the 205 and recently sold it for $2k to TMR.
On your own you may get $2.5k+

Before I sold it I used an Denafrips Ares 2 DAC. It became
oh so apparent that the Oppo DAC was way inferior.
No golden ear required.

My move was to sell the Oppo, buy an Innuos Zen 3 Streamer/burner/storage new. Then I bought an Audio Mirror DAC for $1.5k 
All in at $3.7-$2.0 Oppo money = $1.7 net in upgrade costs but now have everything I need. I did stumble across an Oppo BDP 93 at Goodwill for $18 so I can still play the occasional movie too.