Hpa4, no idea why. The adi's amp was the first one that blew me away though, I went from a schiit jotunheim (that I hated) to a questyle cma400i (sounded underpowered, almost made me miss the jotunheim's higher noise floor but louder sound) to the rme adi 2 dac (which like i said, blew me away, detail and enough power for days).
But I definitely don't seem to be immune to subjective bias. Maybe it sounds better to me because I want it to or think it should? I even have a linear power supply for my rme adi 2 dac which is a no no around these parts, especially with such good power filtering on the rme dac. I do consider myself an objectivist though in the sense that measured performance is very important, but I feel like I hear differences in dac filters etc. I even had my friend help me blind test the filters, sd sharp vs sharp and I was able to pick them out almost every time. I think I was only able to do that because I studied how they sounded beforehand and would listen to those changes. Something about the sharp filter allowed more detail whereas the sd sharp seemed to have more bass impact but would kinda overpower other notes. I've had my hearing checked out and have really good hearing though, especially for someone my age. So that makes me wonder how good some people's hearing can truly be, but it's just a wonder, as I'm no scientist.
As far as subjective experience, I really noticed it's deference in the treble. Something about the hpa4's treble is so realistic it's almost unbelievable. So there wasn't much difference in my subjective experience, I chalked it up to the thx module lowering crosstalk, but I really have no idea, most likely just bias. I did want the xlr output too, maybe that can have something to do with it? I know technically that's not supposed to be true though. But you forced my hand for my subjective experience, so there you go
, kinda feel dirty doing it here though, on an audioscience forum
. I "felt" like I noticed a difference in the treble. Almost everything else the same though and if I was forced to try to blind test all I would focus on would be the treble because of that.