Hm901? Since when that came out..have i been sleeping?
I myself have a hm602.. More then cabrble to go one on one to the iriver or the ibasso in my opinion..the only dap i know of superseeding those is the hm801.. But that one costs 800 usd! And as far i understand the upcoming top tier dap of hifiman with be more into the 1100 usd range..but as far i know its only be showed on shows and not yet on sales right now..
Plugging in a high end low inpedance phone directly on the dap wint give u optimal siund quality..but to be honest..if ur willing to spent near 1000 usd on a dap and more the 1000 usd on a headphone..why ur asking for budget amps then? Am a bit confused now..an amp is just as important in ur rig as the other parts as are headphone cables or even upgraded cables between ur dap and amp and upgraded powercables ( i found out recently myself!)
But ofcourse its all my personal opinion..good luck with ur decision..
lol well i was thinking high end dap is still a dap, maybe it can be surpassed by cheaper desktop gears... and im not sure if the hm602 scales up to dx100's level... some people even prefer it than the hm801... the dx100 is probably what im going to get anyway