@lordcloud
After the shoot-out I wrote these comments for a club newsletter:
The Audio-gd 7 is sweet and warm in a pleasing tube-like way. It's a tad less resolving and extended on top than the other two. Down low, it trades ultimate articulation for increased scale, embodiment, and richness. The soundstage is big in all directions. Uncharacteristically, for all its fine qualities it betrayed a slight glare and aggressiveness in the mid-treble.
The Denafrips Terminator is more disciplined and neutral across the frequency range, and more resolving and timbrally correct and revealing. There is more of leading edges and trails. PRAT is tighter and faster. The bass is more articulate. Bass is leaner, but there when it needs to be. The soundstage seemed a bit smaller and inside the box, though this may have been due to variations in volume during the demo. It was interesting to compare its oversampling and non-oversampling modes. OS mode adds suppleness and mitigates the slight mechanical disjointedness of non-OS mode.
The Aqua Formula (with the recently upgraded USB module) combines the best qualities of the other two, but with more vivid, saturated colors and a quieter jet-black background. It has a rare organic quality that demonstrates both separation and interconnectedness within the whole fabric. The presence region is rich and expansive, but seamless with the high and low regions. This unit rivals vinyl but without the surface noise. It sounds expensive, and it is! Another attendee called it "romantic"-- it may have a house sound that's a bit richer than life.
I conclude that their performances do align in order of price and illustrate the law of diminishing returns that's all too common but still draws us to the big spends. That said, I could happily live with the Denafrips, which has no discernible faults.