I said this a few posts back, but I'll reiterate. I think they both sound superb amped. For distortion reasons, I enjoy and prefer setting-and-forgetting the DAP volume at a reasonable level and controlling the volume with the Arrow. Judging by your hoity toity ;) signature tag line this may not matter to you, but I prefer the Arrow's bass boost to the J3 EQ bass.
Something I haven't mentioned recently is the Arrow produces a wider soundstage and is a little warmer than straight J3. I can definitely blind test tell the difference between my J3 amped and straight.
I mainly leave the J3 amped (Clip is relegated to exercise and garage/yard use) because it's a small enough combo to maintain reasonable portability and it being my main portable "rig" I often switch to my big 300ohm HD650s which require some amping.
It really depends on your usage, Proedros. Are you strictly an IEM guy? Do you own or plan to own some full-sized cans in the future? If you're always on the move, and IEMs are your thing, stick with just the J3. If you're planning for sonic flexibility and want to drive almost any headphone you can get your upgradeitis infected hands on, the Arrow is your best portable friend.
Originally Posted by proedros
Mediaogre , seeing you have the same DAP i have (clip+ / J3) and the amp i am thinking of buying (arrow) i would appreciate your feedback on whether the amp is a necessary purchase and how much better these 2 DAPs sound with an arrow in them.