Been a long time since I’ve listened to a Theta Miles, modified Pioneer player but I’m not surprised it sounded better than a Bluesound Vault on its own. I do remember at the time when the Miles came out I along with the dealership that carried both, preferred the CAL Icon and Tercet over the Miles. Haven’t heard any of these players in years but I own a Vault and with a modern standalone DAC it will significantly be better over these older players in every area. Use a good coax and not the toslink and a better power cord on the Vault as it does make a difference. Also pick up a Supra CAT 8 cable as it is really good and very affordable... yes, better than the CAT 5 cable it comes with. Have not heard the Chord but based on its reputation I suspect it will walk all over your Miles.
Bluesound Vault 2i and a Qutest DAC
In trying to get rid of the thousand physical CDs i own so I demoed the Bluesound Vault 2i against my Theta Miles CD player (with a Krell integrated amp and Thiel speakers.) The Theta produced better sound so I sent back the vault. Someone suggested that I use an external DAC, like the Chord Electronics Qutest DAC, with the Vault 2i to produce the quality of my CD player. Has anyone any experience with this scenario?