Good bass from a DAP?
There is a reason that the brick under your CD player weighs 80 pounds, can't fit in your pocket, and keeps your room warm at night.
Of course, your amp also has to drive much larger speakers (ie, load) than headphones, but just think of the compromises made in components that are used in todays mico sized DAPs.
iPods are not alone in being bass deficint. An old article, but interesting (and with some surprising results):
http://home.comcast.net/~machrone/pl...playertest.htm
DAPs are constantly improving, and are nearly miraculous for their size. But, IMHO, trying to add low bass fundamentals to a tiny amp that struggles in this area may not be the best for overall sound quality. As mentioned, adding an amp in-line with your DAP can substantially ‘flesh out’ your sound. If so, it is the fault of your DAPs amp, not the headphones. I would stay with the headphones that sound the best using a high quality source. Technology is increasing, and as with the shuffle (from article), these deficiencies can be, in large part, addressed, and may be in your next DAP.
BTW- Does anyone else know of other DAPs that utilize transistors rather than coupling caps?