here's a comparison between HE 6 & HE 560 by Srajan Ebaen of 6moons & he prefers the HE 560. But he doesn't mention what amp he is using to drive the HE 6, hence that renders the comparison useless IMO.
Edit : he has mentioned a list of amps used for the review.
Headphone amps: Bakoon AMP-12R and HPA-01, Eximus DP1, Burson Soloist, Stello HP100MkII, Questyle CMA800R, Aura Note Premier V2 and Vita
As far as I am aware none of them are capable of driving HE 6 to its potential. Please correct me if I am wrong.
Edited by punit - 7/19/14 at 8:03am