If people ask us why they would want a dedicated portable music player rather than simply using their phone, our answer is easy — they enable the loading of a wide range of high-res audio file types, they use higher quality DACs and audio stages, and some of them can also double-up for use at home as a DAC as well. You can pay thousands of dollars for these things, but two releases from the same company this year impressed us by delivering excellence at more affordable prices. 
Especially notable in this regard is the new generation of the Fiio X1, at just $139.90. Unlike many high-res portables, including others from this Chinese company, this is not based around an Android OS, so that in its style and operation it’s more like the departed Apple Classic iPod, and has the significant advantage of being smaller than most high-res players, and much lighter, despite quite sturdy metal construction, front panel protectors and supplied decorative skins. 
It’s important to note that this Fiio arrives with no user memory built in; you insert a microSD card to store your music. Once a card is in place, you can plug the X1-II into a computer and drag music into it. DSD fans miss out here, but it can store and play PCM-based files up to 32-bit/192kHz and covers FLAC, APE, ALAC, WAV and AIFF on the lossless front, as well as the usual lossy suspects.
FiiO says it’s good for headphones of up to 100 ohms (though we used higher), and we were thoroughly impressed by both the sound and the measured output, so you needn’t worry about sound quality dropping with the price. It’s only the Android versatility and DSD you miss out on, making the X1 gen 2 a real bargain.
Over $500 (though not by much, at $549), Fiio offers the more substantial X5, now in its third generation. This runs the Marshmallow version of Android, which means you can use the device for all kinds of things beyond playing music by downloading your choice from tens of thousands of apps in the Google play store. There is has 32GB of storage, though a fair chunk of this is consumed by the OS, so you’ll be adding microSD storage to the two premium phone-style trays  on the side. Each can hold a card up to 256GB.
You can take advantage of that space with music in a real plethora of formats, supporting DSD up to double-speed DSD128 and PCM up to 32-bit/384kHz, and we think everything codec you could possibly need (MP3, AAC, WMA, OggVorbis, AIFF, WAV, ALAC, FLAC, WMA Lossless, APE). There’s even Bluetooth support here (as there is on the X1 above), with SBC and the higher-quality aptX supported if your sending device also supports it, though without AAC to assist Apple devices.
This player is particularly strong on outputs, with a standard 3.5mm headphone socket, a 2.5mm one for balanced headphones, plus a further 3.5mm output, which can be switched between analogue line and coaxial digital. A gain switch can limit output levels if you like, as you may wish to do, given the X5 produces extraordinary output power, as well as sensational sound quality into even tricky headphone loads.