Joining the high-resolution digital audio craze — meaning music files that sound much better than MP3s — isn’t as easy as a quick download. You’ll also want an app like VLC that can play the hi-res (24-bit/96 kHz) file you got from a site like HDTracks.com, and then you'll need hardware that can output the extra frequencies. That’s where Apogee’s ONE comes in.

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The ONE is targeted mainly to musicians, but it also includes one of the few mobile digital-to-analog (DAC) converters that works natively with an iPhone or iPad. When connected through the port, the ONE replaces the DAC inside your iOS device, which is only capable of CD quality (16-bit/44.1 kHz) output. 

Though there’s plenty of debate about whether we can hear more than CD quality, the high-res files offer a slightly better sound. Paired with some great headphones, the ONE makes a difference. We heard details in the rumbling bass line of St. Vincent’s “Digital Witness” that got lost on the CD tracks. Its DAC improves MP3 files and streamed music, too. Listening to the War on Drugs’ “Under the Pressure” on Spotify, we heard deeper bass and sharper cymbals compared to listening through the headphone jack of the iPhone 5S.

Measuring 6.4 x 2.2 x 0.8 inches and weighing 8 oz, the ONE isn’t small enough to tuck comfortably in your pocket, but it fits nicely in a bag or backpack. You can power it with two AA batteries or plug it into the wall. And, for good measure, the ONE also includes a built-in microphone in case you want to try your own hand at making high-resolution sounds.
[$349, apogeedigital.com]