Replace Ayre Codex with Topping D90 DAC

@dbphd ,
Are you sure you are using the DAC out and not the Pre out?
That would explain the low volume. 
Whoops, @hgeifman  beat me to it.
If not, then I would pursue an Ayre QB 9. Ayre just offered an upgrade to Twenty status for $1500, so if you found a used one (like I did), you can get a sweet DAC for a lot less than buying new.
The upgraded QB 9 is a significant improvement over the Codex.
Even Ayre says so (which is why I made the move), and they rarely blow their own horns.
Bob

@jchiappinelli, 
Ayre offers upgrades, too.
But, I agree that Schiit DAC's are very good. Though you would need to get a Gungnir or Yggy to compete with the Codex.
Bob