missed the Apogee with ADI.8DS clock ? that was the most important!
the hdsp9652 has inferior clock than the adi-8ds, makes the ADI to sound like Apogee, blurr.
the adi-8ds with apogee clock sounds bad, becouse...
#1. it could be a low quality digital cable,
if you used BNC to BNC or rca to rca with rca to BNC adapters,
that could be 1 reason,
try to use 99.997% true OFC minium for 44.1/48khz, the cheap bang for the buck in cables are philips pxt1000, the 6ft. cable rca-to-rca, and add copper rca to bnc adapters, that cable does not add any cable jitter at 44khz/48khz.
or betters vovox, zaolla, evidence, tesla, psaudio, lavacables.com, APC, etc...
#2. the second reason maybe was becouse you didnt disabled DDS in the RME converter, or do not activated the follow clock feature the QS has, that could be 2nd reason.
or both...
****
anyway...
the best in this test is ADi-8 DS int.clock, more defined/detailed stereo, specially in the L channel. but becouse the clock.
would be nice to hear the:
Apogee Rosetta AD with ext. clock from ADI-8DS with a verry nice digital cable.