I've used an iPod Classic as my on-the-go music player for years, while I was waiting for something better. Sure, Astell & Kern has two perfectly fine players, the $699 AK100 and the $1,299 AK120, but FiiO smashed the high-resolution music player price barrier with the X3, which lists for $299, but which sells for $200 on Amazon and most other online retail sites.
I've favorably reviewed FiiO products before, so I had some reason to expect the X3 would be pretty decent, but it's way better than that. Granted, the X3 can't match the Classic's 160GB storage capability, it has just 8GB of internal storage, but there's an expansion slot for microSD cards of capacities of up to 64GB. The Classic's menu navigation is impossible to beat, but from here on out the X3 takes the lead, it's a much better sounding player, and not just because it plays high-resolution files.
The metal case feels really solid, and measuring a tidy 2.2x4.25x0.6 inches the X3 is nearly the same size as the Classic. The on-board digital converter is a Wolfson WM8740, a true audiophile-grade device. Connectivity runs to USB 2.0, a 3.5mm headphone jack, 3.5mm analog stereo output, and a 3.5mm coaxial digital output. The 2.4-inch TFT display is easy to read. The X3 drives low- and high-impedance headphones, from 16 to 300 ohms.
The X3 has a 3,000mAH lithium polymer battery, and FiiO claims a 10 hour play time with FLAC, WAV, WMA, and ALAC files with up to 192kHz/24-bit resolution. The X3 also handles AAC and MP3 files.
I started listening to the X3 with a set of Logitech UE 900 in-ear headphones. High-resolution 96kHz and 192kHz/24 FLAC files sounded remarkable; there was an open, more vivid quality than I've ever heard from an iPod. Bass definition firmed up, and after I spent a few hours with the X3 the iPod sounded rather bland and boring. One reason for that was the iPod's more limited dynamic punch with my JH Audio JH13 and 1964 Ears V6 in-ear headphones, compared with the sound of the X3. When it comes to hard-to-drive full-size headphones, like my Hifiman HE-400 and Sennheiser HD-580, the X3's performance gains over the iPod only grew wider.
Even when I compared the iPod and X3 loaded with the same Apple Lossless files ripped from CDs the X3's superiority shined through. The sound was more complete, more realistic; the iPod sucked the life out of the music. The X3 was clearly better, even with MP3 files; it's a much better-sounding player, period.
The FiiO X3 is the one to get if you, like me, have been waiting for a music player to take your sound to the next level. If you already own a set of killer 'phones, the X3 would be a logical upgrade, because right now it's easily the best-sounding portable music player I've heard for the money. The X3's high-resolution capabilities are nice to have, but chances are you don't have any hi-res music; the X3 will bring out the best from standard-resolution files, the stuff you have now.