So, what do you think is the most important factor of DAP? Is it the DAC that makes the most difference?
Dac's are pretty close in performance these days. So usually it will be the analogue circuitry, and perhaps the (selectable?) digital filtering that will be the most important factor for the sound quality. That will often be a personal matter, and also depending on how the player and the headphone will 'match'.
For example, a dac such as the RME adi-2 pro is usually praised for it's 'perfection'. It's as close to measurable faultlessness as you can get at the moment.
Yet, it's sound quality to me is underwhelming and uninvolving. (and I gave it a serious chance for about a month)
Apart from the possibility it has to do with 'taste', I am guessing the analogue circuitry is a very important factor here.
With dap's I have very little first hand experience. So I could only give a general comment what I believe would be important as far as enjoying it's sound is concerned.
Obviously it's headphone amp should be of good quality. You'll probably have to read reviews from others what is said about that part.
And it should be a good match to your headphone(s).
It's basic sound signature should be neutral. A good eq would be desired to accommodate for personal taste, low volume listening, and allow for correcting specific headphones.
Perhaps there are dap's with good parametric eq's? I really don't know.
Also, I would not want a dap that doesn't recognize replaygain tags.
And a well-implemented crossfeed function would be nice to have.
There is an existing MusicBee thread somewhere, specific about advice on- and experiences with dap's.
The title of this thread is more about lossy vs lossless in regard to dap's.
Perhaps turn to the other thread to see if you can get some input from members about specific experiences and recommendations on dap's?