Along with a standard USB cable, the U2 includes a key-size USB adapter for on-the-go PC connectivity. JetAudio smartly molded a key-ring hole in the adapter's plastic casing, so you'll likely have it with you at all times. We do wish the included earbuds were woven into the lanyard to cut down on dangling wires.The JetAudio iAudio U2's setup process is as straightforward as you could hope for: Simply plug the player into your PC's USB 2.0 port and start transferring. The U2 shows up as a drive letter in Windows Explorer, and you can drag and drop music files directly into the player. (MP3, protected WMA, OGG, WAV, and ASF files are supported.) The U2 also comes with JetShell, a basic two-paned music transfer utility, and JetAudio, a snazzy music jukebox, but we ended up using Windows Explorer and Windows Media Player 10.0 for most of our music transfers. Just remember to append your music files with track numbers, or they'll play in alphabetical order.
The U2 comes packed with playback options. First up is a five-band equalizer with presets for rock, jazz, classical, pop, and vocal, along with a user-defined mode. You can also mix in some bass and treble enhancers using BBE and Mach3Bass; add the 3D Surround effect, which just sounded echoey to our ears; and tweak the Pan setting, which is essentially the balance control. Several repeat modes are also available, as well as a shuffle mode and autoresume, which lets you power-off the U2 and later pick up your music where you left it. The U2 lets you create playlists on the fly, but it doesn't support M3U playlists created on your PC; again, JetAudio promises that such support is coming in a future firmware release.
The player's built-in FM radio boasts an above-average 24 presets, and the autoscan feature will find the clearest frequencies and add them to your presets. Unfortunately, the U2's ability to record FM stations (as well as line-in and built-in mic audio) falls short. While you can record directly to MP3, your choice of bit rates ranges from only 96Kbps to 128Kbps, and there's no WAV recording. We'd prefer the ability to record at lower bit rates for long speeches or interviews or make high-bit-rate WAV recordings for music and concerts.The JetAudio iAudio U2 sounds as good as it looks. With its barely perceptible hiss (95dB), its detailed highs, and its impressive bass (20Hz to 20KHz), we didn't feel the need to gussy up the sound with the player's various mixing effects. We were even impressed with the included, dumbbell-shape earbuds, although we'd still recommend swapping them out for a better pair. There's also no shortage of volume; thanks to the U2's 13mW-per-channel output, you can easily crank it up to earsplitting levels.
If the U2 has an Achilles' heel, it's battery life. We got 15 hours of music from the U2's built-in lithium-polymer battery, 5 hours short of JetAudio's specs--not bad but not great. Transfer rate over USB 2.0 was a below-average 1.86MB per second.