I just met with Axel Grell in our headquarters and he has provided the following explanation.
"Some customers found some 24Bit 192kHz files create noise when played via USB on the HDVD 800. We have analyzed the files and found they contain information above half of the sampling frequency. This leads to interference and noise when not pre-filtered before digital/analog conversion according to the Nyquist theorem. There is a failure in the files that must have been done in the mastering process. Other DACs do not give the full resolution and avoid this problems. In the meantime we are looking for a solution that allows the full bandwidth as well as a limited bandwidth for non-standard conform files."
Now this made me kinda hate Sennheiser, this is just a lame excuse. Axel Grell said something very silly about the balanced Senn headphone cables as well, that the negative phase is reducted in the transducer or something like that. But there is no negative phase in the first place...
And frequencies above 96kHz are definitely useless. Not only that, but this is a headphone-amplifier and there are no headphones that go beyond 96kHz or get even close, heck, nothing even reaches 60kHz (AFAIK) because the HD800 reaches 44.1kHz (51kHz but that's -10dB...) and the SR-009 (which doesn't even work with this amp) reaches 42kHz.
They just grabbed a cheap-ass DAC, didn't bother testing is properly and marketed the hell out of it instead and now there are too many issues, especially for a flagship unit.
I can only like them again if they'd recall the units and fix all of them but they got their money so they probably don't care anymore.
Excuses is all that they're giving now, because they don't want to damage their reputation.
Sure the excuse has a point, but the entire industry disagrees and they know that very well themselves.
Hopefully they'll find a "solution" for your guys, otherwise you'll have to make do with a cut-off filter in foobar that cuts of at ~96kHz, there are no headphones that reproduce this but you did pay for bit-perfect and that's what the fancy marketing video said so it's a bummer really...
Edited by MelvinV - 6/21/13 at 4:20am