I'm impressed with the AK100 and really enjoying getting to know it.
I can't compare with other high end DAPs because this is my first step beyond lower spec MP3 players. I did compare playback of an MP3 track (320 kbps) on my old Creative Zen with the AK100 and there was no earth shattering difference (music slightly clearer on the AK100).
However with CD quality files and above the AK100 is great. It's able to drive all my headphones really well, i.e.:
* Sennheiser HD595
* Beyer Dynamic DT770 pro 80 ohm
* Grado SR225 (comfort pads with the middles cut out!)
* Grado GS1000
* UE triple fi 10 pro (6N OFHC cable)
Each of the phones retain their usual characteristics but these are the things that I'm most pleased about:
* The GS1000s can be driven really well by the AK100 without amplification
* The UEs sound far better than I was expecting given that they are IEMs
* I can now get good volume and great sound from the DT770s when travelling (without disturbing others of course)
* The HD595s still sound quite subdued compared with the other phones, but this is the best they've sounded for me
Some other conclusions from trying different things:
* using my headphone amp with the AK100 degrades rather than improves sound quality (it's a Naim HeadLine with Flatcap2 power supply)
* I know there's a lot of debate about this elsewhere, but to me higher res files (24/96) do sound noticeably better than CD quality files (16/44); for example when testing with Donald Fagen's Morph the Cat:
· mid-range was more assured
· vocals were more rounded
· bass was better controlled
* GS1000s sound wonderful for many types of music but at times are a bit too bright for me
* The AK100 sounds great as a source for my main amp and speakers (a "vintage" set up of Naim NAIT2 amp and EPOS ES14 speakers) and I'm delighted with how high res music sounds. While for CD quality music the AK100 is not as capable as my Naim CD3.5, with higher res music it sounds wonderful, noticeably better than the same music on CD.
* Comparing headphones: for some music (e.g. dreamy Kate Bush stuff) the GS1000s are unbeatable, however there will be times when only the HD595s will do (and now they are viable to use when travelling on trains etc), but my best all-rounders remain the SR225s
By the way, the music I played when comparing phones was:
Donald Fagen – Security Joan from Morph the Cat (24/96); Bruckner Orchestra – Tchaikovsky Waltz of the Flowers from The Nutcracker (24/96); Richard Hawley – Time will bring you winter from Standing at the Sky’s Edge(16/44); Peter Gabriel – Mercy Street from Live in Athens (16/44).