Don't bother Man. Speaking as an AK240 owner who bought the DX90 as a 'spare' and discovered that the DX90 is an awesome DAP with neat synergy with the SE846. Don't get me wrong the AK240 is an awesome DAP. The SE846 sounds great with the Blue filter sans DX90 but plan to 'lift' it a little with the White. I think that's really going to cut it.
Great to know, DX90 is rocketing up my interest list. Any hiss at all? I have a very very small amount on my Geek Out 450. Certainly something I can live with. But a DAP is still mighty intriguing, due to the on-the-go possibilities.