I'd wager a LampizatOr money that a LampizatOr Gen 4 Level 4 would sound better than anything else mentioned in this thread. I moved to one directly from a Metrum and could tell in less then ten seconds (without burn in) that the Lamp was a MUCH better DAC.
I also have friends who sold AMRs in favor of it. Keep an eye on the used market as you won't do better, but keep in mind I wasn't a huge fan of the Generation 3 DACs (my former Metrum replaced a LampizatOr Gen 3 Level 3 in my system).
I also have friends who sold AMRs in favor of it. Keep an eye on the used market as you won't do better, but keep in mind I wasn't a huge fan of the Generation 3 DACs (my former Metrum replaced a LampizatOr Gen 3 Level 3 in my system).