One thing I will say is my usage of a DAP for 4 years now has pretty much been restricted to 16bit ALAC/FLAC or more commonly 24bit 96khz vinyl recordings and live concert recordings. A 20 song concert can be upwards of 3gb total so this is a much different usage from 1000s of mp3s. Man on a bad UI, I could not imagine going through a library of MP3s on two 200gb SD Cards. Bigger files are certainly more difficult in what the DAP processor and BUS speed of that DAPs can handle when reading off the micro sd card.
You might be just fine with mp3s n an AKjr. My recent DAP research when I made my decision was from those using it as a higher-res player. Obviously there are people on both sides of the fence when it comes to whether it makes a difference in quality going even to 16bit which can be at rates up to 1250kbps. As opposed to 320kbps mp3s. People spend a lot of money on this forum for headphones that will out resolve lesser models, however these same audiophiles are listening to chopped out data in a compressed MP3. Dynamics are limited at best and dynamic range is just simply noticeable to anyone that has listened to hi res for months or years of time. Sense of space is much different in my opinion in 24bit. Does not have to be 96khz either. 48 kHz is plenty and I will tell you why.
This is a really political topic I am sure on this forum so I will be tactful here, but I really have never heard anyone put it in this way so I thought I would share. When we went from DTS and Dolby Digital 5.1 16bit lossy compression to DTS Master Audio and Dolby True HD 24bit 48khz (hint hint) the soundstage in everyone's room opened up to an audio quality no one had heard before. Any home theater audiophile loves it. More dynamic range people? Time and time again I read the merits of 24bit refuted to having no effect. Then I say to them, why don't you go back to your Dolby digital sound track because it makes not difference going to from 16bit to 24bit.
I digress from this thread, but it is important and I think for newbies to DAPs on this forum that have you post here in the intro forums for a bit before playing in the other forums, you have to ask yourself why you are spending the money on one of these players. I think here on this forum, this thread can continue to grow for people interested in something other than their cell phone because a $300 priced DAP really moves you into another league for SQ in the portable market especially with harder to drive headphones.
DACs are built and spec'd to perform at different sampling rates. Why we would pay money these days over our cell phones to play mp3s is beyond me. Cell phone interfaces or the iPod touch as a non cell are much easier to operate and are higher res
screens typically than what you can get on any of these DAPs. I would take an iPod touch with a FiiO Q3 that is coming out for probably less than $150 as a nice thin stack over any DAP if I was only going to listen to MP3s on it. Any of the inexpensive FiiO DAC/amp combos would be a great match for your cell or an iPod touch or nice hi res screen android variety. Tons more options too. You get a real App Store. Best of all worlds and I cannot wait to when we can buy a $300 DAP with the best of both worlds in one small deck of cards.
In my opinion you are buying anything in the $300 price category for DAPs to improve sound quality. And while you will improve the sound quality of your mp3s. In my opinion revealing the distortion and lack of dynamic range in mp3s more vividly to you is what you will experience more often.
Anyone purchasing one of these mid priced DAPs should do themselves a favor and grab a few of your old favorite CDs and re rip them to 16bit FLAC or ALAC and don't judge right away. Fill up a card and listen for weeks. Then go back to the same CD rips but those in even 320kbps MP3. You decide whether you want the compression or not from there using your beautiful new DAP DAC/AMP player and nice set of cans.
As you can tell I love DAPs. It really offered me the ability to share high quality recordings to a lot of people that would have otherwise not heard it. I took it personally back in the 90s when Napster and the MP3 basically Titanic blocked 24bit audio in the SACD and DVD Audio. And I am seeing a similar revolt on it again these days, so there you have it. Cats out of the bag. I pay good money for equipment. I want to get the best out of it. A little bit of a nitrate snob
Properly reproduced with a good set of mid to hi end headphones, high quality 24bit recordings can reveal a different listening experience with these higher quality digital audio players. I find it much less fatiguing as well. Oh the sibilance I have relieved myself from