One thing good about Beyerdynamic is that they sell nearly every individual replacement parts for their headphones.
Anyway, of all the DT880s, the 600 ohm has been the more "liked" headphones of the lot (32, 250 and 600 ohm) so I guess the fact that the frequency-response curve hugs the Harman curve for a majority of the range says quite a bit. But no other "reviews", by subjectivist or otherwise, have mentioned the low end distortion yet (perhaps I wasn't paying attention) but most have noted the overall "brightness" of the Beyer's tuning. So thanks Amir for objectively showing that (Also Solderdude's test).
Also, the chap at "Youtube - No themes review" has mentioned that high output impedance amp (100ohm) is the way to go for driving this headphone well from his tests. I do not understand the science behind this but Beyerdynamic's own very expensive A20 headphone amp has very high output impedance (100 ohm) so I think it kinda make sense if one presumes Beyer knows how to match their products. Such high output impedance amps go against the grain of the vast majority of the "top of the class" amps tested by Amir. (The above chap recommended the cheap Samson s-amp which has 100 ohm output impedance as an suitable low cost match amp for this headphone.)
If there is a logical scientific reason for this, would testing the headphone on different output impedance amps yield a different result? Would the distortion result change?