I own the original AK70. It's wonderful. I'm not especially discerning, but I know the quality is great listening to many 320 both mp3 and AAC, and a whole bunch of lower bit rates of somewhat suspicious quality, using B&W P5 Mark II, HD600, and even H5 and Bose A2E. And I am usually listening not in a noisy environment, but also not a perfectly quiet one. I listen mostly to old Top 40.
So, my question. Given how my variables resolve, would I likely notice the increased quality of the Mark II version?
(P.S. - And should I be using a portable amp with the HD600?)
Thanks.
The main things to look at are:
- do your headphones get loud enough?
- is there an audible noise floor? (this can be a problem with sensitive in-ear headphones)
- is there a high output impedance? (which can mess up the headphone frequency response)
The AK70 specs say it has a 2 ohm output impedance. That should be fine with 16 ohm (and up) headphones.
Aside from that, if the max volume and noise floor are satisfactory for you, I don't think there will be anything to improve on.
(P.S. - And should I be using a portable amp with the HD600?)
The only reason to is if they don't get loud enough. I use mine out of a macbook pro and it's just loud enough for me (I put the volume at 100% volume very rarely, for quiet / classical music).
I thought that getting loud enough was not the way these things are analyzed.
It might be loud enough, but if the amp of a unit is being driven to its max, then perhaps some distortion is creeping in.