bagwell359
Headphoneus Supremus
I think its because the 400i is just hard to drive, so when you dont feed those enough power, these will sound thin and have sibilance.
Similar story with the 560.
I didn't find that. I can drive HE-6 6 screws and HE6se on my Ragnarok 1, and the 400i like the 4XX has too much mid bass and upper bass but missing low bass, and sort of a wild treble complete with ringing.
The 560 v1 is a much cleaner affair, too clean actually. its missing the rich depth of the 500 and 6. It's very scrubbed sounding with a big bright spot around 7k, but somehow missing delicate touches like overtones/decay. With an EQ or in line network you can remove the brightness, but it doesn't restore what's missing. It's the closest to the Ananda among the old round models. At the used price it's a pretty good deal.