Yes, PM please or email ryan@vaporsound.com
Do you know Ryan if that DAC is performing oversampling beyond the 32bit digital volume processing?
I've recently come to the conclusion that oversampling hurts audio quality due to qualtization errors/noise and resulting in dithering being performed that does have a perceived affect on the higher band from interpolation even if at high bitrates. I think there is an unknown psychoacoustic negative perception occurring.
I know the ESS DAC does oversample everything for the volume to be attenuated digitally at 32bit. This isn't oversampling that's actually adding information but is padded digitally before being processed I think though not certain. The thing is the DAC's firmware/microcode can be programmed to also perform classic oversampling with the anti-aliasing filter being performed ahead of the sampler.
This is where I believe the perceivable sonic damage is done to the source via this "folding" as it creates upper order harmonics that have to be filtered by the AA processing.
For anyone interesting in understanding this stuff, as I'm trying to do, these videos are a fantastic primer.
http://www.youtube.com/watch?v=W2-FP7twy8shttp://www.youtube.com/watch?v=HqHIOA-Fcuwhttp://www.youtube.com/watch?v=D4dfZj8pi2Ahttp://www.youtube.com/watch?v=j24Yt77ALf8DITHER vs. NO DITHER
http://www.youtube.com/watch?v=IRlohQw-1DYThe trucation distortion from dithers is the problem IMHO!
The problem is most DAW work flows are 32bit floating point internally so they are always downsampling post production and performing this bloody dithering!
The irony is that the endusers are then upsampling via their DACs a dithered downsampled signal!
Part the problem is also the converters used during production.
If you look at all of the signal processing/conversion done from the point of capture to the enduser/listener via poor distro and audio rendering it'd understandable a lot of keen ears are so into vinyl because this will avoid perhaps one or two layers of these SQ damaging conversions.
I just read an interesting document entitled "Condemnation without Examination is Prejudiced, or Words of Wisdom" by John Curl and was very intrigued with the concept of PIM and am also working through other papers he cites in the piece.
Though not similar in how these psychoacoustic results are produced I'm starting to think this FM distortion due to ignored high order HD that people seem to perceive due to FM noise and phasing issues in the passband is probably one in the same.
Are these higher order distortions out of passband resulting in FM and phase distortion/IM in the passband that we are perceiving?
How does this affect the reality that our flawed stereo playback systems (creating 4 unnatural sound arrivals) is obviously creating a psycho-acoustic perceived phase shift combined with P/IM as well as the real phase and IM issues? Is this due to PIM perception? If PIM is real what is it's operational relationship with the 4 arrival flaw in a psycho-acoustic sense? How does interoral time delay play a role?
Perhaps the noise people seem so keep to introduce (warmth) is masking our perception of this phenomenon...
How do we go about effectively testing for this FM/PIM distortion in the lab? How to we quantify and measure it in loudspeaker system and include the psychoacoustic element?
