But isn't there anything else? In my mind where you need a stable current augment is when the impedance will change significantly (in replaying low/medium/high frequency).   So if I put the question in another way: the significant change of impedance typically happened on what kind of...

Hi guys,   I'm looking at cma800r AMP which asserts to feature a current output. But am wondering what kind of headphones suits this mode? Dose it have something to do with the impedance or the sensitivity?   Anyone ever got a chance to compare it to bakoon HPA21?   Cheers.