Four Superb Portable Headphone Amplifiers (and Amp/DACs)

Many Playback readers have become fans of portable hi-fi systems where the notion is that all—or nearly all—system components should be small enough to fit in your pocket, handbag, or backpack. 

For many listeners, the game starts by acquiring a good set of earphones or perhaps custom-fit in-ear monitors that can be plugged directly into an iPod or other portable digital music player (including, in some cases, laptops, netbook or tablet PCs, etc.). But over time, the logical progression of things—not to mention our innate desire to take musical excellence to the max—often leads us to a quest for high-quality portable amplifiers (some of which come with onboard DACs).

With that thought in mind, let’s take of a look at four of the best portable amplifier options Playback has encountered thus far, weighing the particular strengths (or possible downsides) of each model in turn.

ALO Audio Rx Mk2 Portable Headphone Amplifier ($449)

http://www.avguide.com/review/alo-audio-rx-mk2-portable-headphone-amplifier-playback-43

What it is: A pure, straightforward, and beautifully made headphone amplifier (sans onboard DAC) that can successfully drive a very wide range of earphones, in-ear monitors, and headphones.

Why you might choose it: To paraphrase the words of acerbic political advisor James Carville, “It’s the sound, stupid.” In a world where many headphone amps sound a bit bright, brittle, and a little too edgy for their own good, ALO’s Rx Mk2 offers a wonderfully warm, rich, natural sound that offers vibrant tonal colors and enough power to drive most headphones.

Visit one of the popular Head-Fi Can-Jam events and you’ll see any number of headphone/earphone manufacturers using the Rx Mk2 as their reference amplifier of choice. There are at least four reasons for this. First, the little ALO is beautifully made and very sturdy. Second, the amp’s onboard battery pack and clever charging system make for A) lots of playing time per charge, and B) the ability to do partial recharges without having the battery develop a “discharge memory” that will limit playing time in the future. Third, the amp offers two switch selectable gain ranges, which makes it easy to adapt to ‘phones of widely varying sensitivity ratings. Fourth, as mentioned above, there’s the sound, which tends to show most ‘phones in a very positive, flattering light.

Why you might look further: Much though we like the Rx Mk2, we can think of two reasons you might not choose it. The first is price: at $449, the Rx Mk2II isn’t cheap, but then truly good stuff almost never is. The second is the fact that the Rx Mk2 is purely an amplifier, whereas your particular needs might be better served by a combination amp/DAC.

CEntrance DACport ($399.95)

http://www.avguide.com/review/centrance-dacport-2496-usb-dacheadphone-amplifier-playback-34

What it is: CEntrance’s DACport is a bit of an iconoclast in that it is a tiny, roughly cylinder-shaped, and entirely USB-powered combination high-resolution USB DAC (96kHz/24-bit capable) and—get this—pure class A-powered headphone amplifier. As such, the DACport is offered as a potentially ideal companion product for listeners who prefer to use laptop computers (or other devices with USB interfaces) as their source components of choice.

Why you might choose it: when you get right down to it, one of the main reasons to buy the DACport is to enjoy the cumulative benefits of the many different advanced technologies that have gone into its design. CEntrance, as it happens, is a high-powered technology consulting company whose clientele includes makers of DACs for the high-end audio and pro-sound (think, recording studio) communities, as well as a large number of manufacturers of chip-level DAC devices. All of these clients have turned to CEntrance to tap the firm’s expertise in the areas of USB interface design, device driver design, and jitter reduction technologies—expertise that has most definitely found its way into the deceptively simple-looking DACport.