I had a loan of a Theta Miles CD player a few years ago, it was very hard to give it back. It has a PCM63 DAC on board. Such an involving and warm sound if not the most detailed. It kept asking you to push up the volume and when doing so on rock it was very addictive. In the end the Meridian 507 I compared it with didn't sound too different (a little more anemic and not quite as much fun). I went with my head rather then my heart, the Meridian was the safer bet as I knew it's very little used history.
I also had the big Theta DAC here which offered the same fun but slightly more so. The seller wanted more than I could pay for it though and the inputs were a very limiting factor too.