NEED HELP WITH DAC UPGRADE

I have the Mytek Manhatten and can confirm that the DAC makes a heck of an upgrade.

Opps! typo - should be DEQX

thread with little real info here:
https://forum.audiogon.com/discussions/is-deqx-a-game-changer

their site:
http://www.deqx.com/

some people have complained about the manual & setup - Google deqxpert bad reviews

maybe wait for the next version(?) - I think it might be the next place to toss $5k at in home audio, tho it is not clear why it cannot be done for $500 with some mass production...

I have the BDP-1 as well and just purchase the Ayre Codex about 3 weeks ago to replace my BDA-1 and it's  definitely an improvement all around more detailed, soundstages  more open and imaging is more pin point. Also works very well with my new Focal Elear headphones. Plus the fact that you are now bypassing the soundcard in the BDP-1 which also  improves the sound quality of both units. 
The only complaint I have is the Codex required approximately 500 hours break in. 

I don't  think you can beat the PS Audio DirectStream Dac. Expensive but a value when compared to many others. It's a wonder of breakthrough design and engineering. 

Or the PS Audio Direct Stream Jr at $4k (reduced with any trade in up to $1200 in retail value). Awesome unit