1. Sibilance is a headphone non dampened flaw, not just your source.
2.I haven't heard the Auditor so I don't know but some reviewers here have reported that the Auditor is an Phonitor without the meters and crossfeed, if true I disagree that this is a crap combination.
3. Comparing the AKG K701/702 to the HD800 is just a plain joke, the 701's are brighter than the HD800. Yes the HD800 does have a peaky treble but you cut this down by doing the Anaxmod and powering it with proper amplification. Throwing tube amplification at the HD800 doesn't fix the problem.
4. The HD800's are studio headphones I know of worldwide famous DJ's and some musicians/engineers that use it for monitoring. Tyll can't recommend the HD800's enough for monitoring purposes only.
5. The HD800 isn't some headphone you can plug into a pos amp or ipod and expect it to sound good.
I'm amazed the HD800 is still held in such high regard on head-fi. Combination of high price setting and consumerism has lead most people to believe "more expensive is superior". Then turn around and need to perform one of many mods to it, and add distortion in the audio chair (by tube amplifiers) to have a headphone where the treble doesn't stick out like a sore thumb.