Four Superb Portable Headphone Amplifiers (and Amp/DACs)

Viewed as a DAC, the DACport sounds highly detailed, focused and revealing—more so than many standalone DACs that cost as much or more than the DACport does. In terms of extension, definition, and refinement, the DACport simply sounds more expensive than it is. Note, too, that the DACport comes with self-installing plug-and-play drivers that makes installation in either PC or Mac-based systems a snap.

Viewed as a headphone amp, the DACport is also astonishingly capable, though like almost any class A amplifier it needs to be fully warmed up in order to sound its best. Once warm-up is complete, however, the tiny DACport sound great and can drive all but the very most power-hungry full-size ‘phones without a hitch. The only sonic drawback we could identify was that the DACport’s mid- and low-bass could sound just slightly lightly balanced relative to some other headphone amp/DACs we’ve tried (which may reflect the fact that there is only so much power you can possibly pull from a USB port).

Why you might look further: Wonderful though the DACport can be in its intended use context, we can think of several reasons you might look elsewhere. The first reason is that—for obvious reasons—the DACport can only be used with devices capable of providing power through USB ports (meaning you cannot, of course, run the DACport directly from an iPod). Second, you may or may not find the bass balance of the DACport to your liking (it works great with many headphones, but not all). Third, you may need or want a bit more power output than the DACport has to offer. Still, in terms of sheer sonic sophistication, the DACport plays way above its pay grade, which is a huge part of its appeal.

NuForce Icon Mobile ($79)

Playback Issue 19

What it is: An almost ridiculously affordable combination headphone amplifier/DAC that offers a substantial step up in sound quality from box-stock iPods, etc.

Why you might choose it: while the Icon Mobile is actually one of NuForce’s oldest products, it enjoys a certain evergreen appeal—largely because the product concept was so very clever to begin with, while the price (a mere $79) is also right. Here’s what $79 buys you: a class D headphone amplifier with switch–selectable gain settings, plus a USB 2.0 DAC that can support up to 44.1kHz/16-bit or 48kHz/16-bit audio files, all fit within an enclosure that is only slightly larger than a typical business card case. Seriously, the Icon Mobile is ultra-compact, which is but one of the reasons for its enduring popularity.

Sonically, this little amp offers good extension at both frequency extremes with what I described as “taut, well-defined bass and an impressive ability to resolve very fine, low-level midrange and treble details.” If there is any drawback, here, it might be that the amp tends to exhibit a touch of midrange/lower treble forwardness, though this can be mitigated somewhat by giving the amp plenty of run-in time, which helps smooth its sound. Happily, the little Icon Mobile has enough grunt to power just about any earphone and most full-size headphones (though it probably wouldn’t be the best choice for driving certain power-hungry top-tier models).

Why you might look further: If you’re willing to spend more and to accept units with slightly larger enclosures, you can find amp/DACs that offer even better sound and DACs that can handle high-resolution (e.g., 96kHz/24-bit) audio data files. But judged on a “bang-for-the-buck” basis, the Icon Mobile is very tough to beat.

Qables iCube V1 Headphone Amp ($549) and V2 Amp/DAC ($699)

http://www.avguide.com/review/qables-iqube-v1-headphone-amp-iqube-v2-headphone-ampdac-playback-38

What they are: From the Dutch firm Qables come two closely-related sibling products—the V1 portable headphone amplifier and V2 portable amp/DAC.

Why you might choose them: Let me start by mentioning an intangible, which is apparent or perceived build quality. If you run your fingers over the casework of the V1 or V2, or simply study how they are put together, you may come to feel—as I do—that they exhibit something of the vibe of an old-school German camera (think vintage Leica, for example). Whenever you interact with these Qables products, you just can’t help thinking, “Man, these are really nicely made.” The even better news is that the fine exterior look and feel of the components is reflective of the sonic goodness within.