Audeze LCD-2
Audiobyte Hydra-X
Power Inspired AG500
Sennheiser HD800

…”Personally, they have made it very hard for me to actually choose one over the other.
For Audeze I loved the 1793 PCB as the sound opened up a lot and the imaging became better, improving exactly what was needed with these headphones.

The sabre32 made HD800 more punchy, giving it deeper bass also, better transients, tactility and energy .
So, overall, I loved the 1793 with Audeze and the Sabre 32 with HD800. However there were a lot of situations when i preferred the other.
It is annoying I don’t just have a button to press to switch the 2 pcbs.

So Burson did another fine job with the 1793 PCB.

It would be even more awesome to make another PCB that combines all the strong points from both actual implementations.”

Full Review Here: http://headmania.org/2013/08/26/new-burson-1793-dac-pcb-review/