FiiO's best portable music player is more affordable than Astell & Kern's cheapest

The new FiiO X5 high-res music player is a wee bit smaller than the original X5, with a different button layout. The new player feels nice and substantial in your hand compared with the skinnier and much smaller Sony Walkman NWZ-A17 high-res player, or the sleeker Astell & Kern Jr player. For me, sound quality is the deciding factor, and the all-new X5 ($349, £289, AU$479) is a major contender and a remarkable value. If you're serious about sound, you need one of these players.

The X5 2nd Gen's menus and navigation are a little better than FiiO's other players, but I still much prefer my iPod Classic and Walkman NWZ-A17's GUIs. The X5 2nd Gen plays up to 192 kHz and DSD128 high-res files (the NWZ-A17 doesn't play DSD), and standard res APE, AIFF, MP3, FLAC, ALAC, WMA, and WAV files. Connectivity options include Micro-USB 2.0, plus 3.5mm jacks for headphones, and an analog line out that can also be used as a coaxial digital output.

The X5 sports a 2.4-inch (6.1cm) display, and the body measures 4.3 by 2.5 by 0.6 inches (109x63.5x15.3mm) and it weighs 5.8 ounces (165 grams). Storage capacity maxes out at 256GB, via two microSD 128GB slots, but the player lacks any built-in storage. I mostly used the X5 as a portable player, but it can also serve as a desktop USB digital converter/headphone amp. The battery charges in 4 hours and plays 10 hours. A slip-on silicone cover is included with this X5.

I listened to the X5 with a bunch of headphones, starting with my Ultimate Ears UE900S in-ear headphones with a few high-resolution DSD files of Miles Davis' "Someday My Prince Will Come" album. Right away the X5's audiophile credentials were established. The sound was crisp, clear and clean, the soundstage was immense, yet image focus was razor sharp. I've reviewed a lot of uber high-end gear of late, but sitting here with the X5 and the UE900S headphones the sound was superb. Wilco's "Yankee Hotel Foxtrot" album in 96 kHz/24 bit high-res was just as revelatory, the strings were sweeter than I remember, and bass definition was excellent.

Standard resolution, lossless files were slightly less transparent, but most of what I liked about the X5's sound was intact, with a good recording and a decent pair of headphones the X5 2nd Gen provides spectacular sound quality.

While listening over the new Hifiman HE400S full-size planar magnetic headphones (look for my review in a few weeks) I compared the X5 with the Sony NWZ-A17 player, and it was no contest. The X5 sounded big and powerful, with full bass, and impressive dynamic prowess, the NWZ-A17 was lightweight with more limited dynamic punch. It's not bad, but if you need an occasional adrenaline rush from your tunes, the X5 would be a better option.

Comparing the X5 with an original X5 the sound at first was not so different. The new one is clearer and precise, the old X5 is a little softer and warmer in tonal balance.

To finish up I brought out my Astell & Kern Jr player, and that one sounded even more transparent and lively than the X5 2nd Gen. The Jr's bass definition was also superior, but the X5's bass was fuller and had more oomph. I'd give a slight edge to the Jr for overall sound quality, but it is a more expensive player, it's $499 in the US, £399 in the UK and AU$699 in Australia.

With the X5 2nd Gen the cost of entry to the audiophile leagues of portable players is now low enough to attract a wider audience. Of course, you definitely need a first-rate pair of headphones to hear the X5 2nd Gen's greatness. The UE900S or Hifiman HE400S I referred to earlier, or the Audeze EL-8, Audio Technica ATH MSR7, Beyerdynamic DT880, Grado GH1, or Noble Audio Savant headphones will do nicely.

The X5 2nd Gen is FiiO's best player, the company also offers the more affordable X3 2nd Gen and X1 players.