Meridian Explorer USB D/A processor/headphone amplifier

Those of us who groan at the appearance of every new five-figure digital source component in a massively oversized chassis—and who groan in greater torment when the offending manufacturer says his customer base insists on products that are styled and built and priced that way—can take heart: The appearance of such sanely sized and affordable products as the Halide Design DAC HD ($495) and the AudioQuest DragonFly ($249) would suggest that the market has a mind of its own.

Yet more good news comes in the form of Meridian Audio's Explorer ($299), a 4"-long USB digital-to-analog converter from a company that many hobbyists would name as one of the industry's premier digital specialists. That the Explorer is available not only at traditional Meridian dealers but also at a growing number of single-brand Meridian boutiques—locations now including Fort Lauderdale, Moscow, and Kuwait—may be seen as icing on the cake.

Ken Forsythe, Meridian America's director of product development, says his company hasn't turned its back on the high-end audio and video markets. "But if we want to be around 100 years from now, we have to go beyond our core. We think of computer-centric users as the new enthusiasts, so the question becomes: How, over time, can we grow them into core customers?" The answer, Meridian believes, is in the form of this, their first portable processor.

Shaped like a Bic disposable lighter and sized like a Pez dispenser, the Explorer is built into a lightweight aluminum alloy tubewith a hard-anodized finish. A plastic cap at one end incorporates a USB mini-B jack—chosen because a full-size B jack would subject the internals to excessive stress—while a similar cap at the other end holds two 3.5mm jacks: one for headphones, the other for line-level audio output. The latter is combined with an optical digital-audio output—rather like the headphone jack on the back of an Apple iMac—to address the TosLink input of any outboard D/A converter. One might see that as an effort on the part of Meridian to emphasize both the Explorer's portability and its usefulness in a domestic system that already contains a high-end processor from Meridian (or anyone else, for that matter).

The Explorer requires only 5VDC, which it gets from the USB bus of the associated computer. It operates in asynchronous mode, using Meridian's proprietary software to reclock the incoming datastream. The converter chip of choice is the 24-bit/192kHz PCM5102 from Texas Instruments, followed by an analog section that Meridian describes as containing especially good-quality parts for one so humble. (As I could find no way to crack open the Explorer without destroying its aluminum shell, I didn't go poking around.) The Explorer's 130mW headphone output incorporates a 64-step analog volume control, while the line-output jack itself is fixed in level.

While I wasn't able to see for myself the Explorer's build quality, I can nonetheless comment on the whereabouts of its construction: Meridian's least expensive product is, like the rest of their line, made in England. Ken Forsythe relates this, too, to the company's efforts at "building their brand," so that new customers might someday step up to Meridian's more expensive gear: "We couldn't build products overseas and still be able to look our new customers in the eye and say, 'This is built in the same place as our finest products.'"

Installation and setup
In addition to a black-velvet travel pouch—another inducement to portability!—the Meridian processor is supplied with a very flexible 6" cable, used to connect the USB-A socket of the associated computer with the mini USB-B socket of the Explorer. As far as I can tell, there exist no aftermarket, perfectionist-quality versions of this digital cable; I'm keeping my fingers crossed that, if and when that day comes, the industry will keep stiffness, expense, and speculative fiction to an absolute minimum.

There do, however, exist aftermarket cables for use with the audio-out jack at the Explorer's other end: a genre in which AudioQuest has recently become a major player, owing to the use of a 3.5mm output jack on their own DragonFly DAC. For the Meridian converter, I used the same 5m length of AudioQuest Yosemite—a three-conductor interconnect with RCA plugs on one end and a 3.5mm mini-plug on the other—that I used when I reviewed the DragonFly in October 2012.

As with most contemporary USB DACs, getting the Meridian Explorer and an Apple iMac computer to play nicely with one another was as easy as losing one's health insurance. After connecting the USB cable and opening the Sound window of my G5's System Preferences menu, I found the review sample listed as "Meridian Explorer USB DAC Out"; once I'd selected it, neither the Explorer nor my iMac ever seemed to forget the other. Explorer owners who wish to use their new converter with a Windows operating system must first visit the Meridian website and download and install the appropriate driver file. (The OS specs for PCs listed on Meridian's website are "Windows XP SP3, Windows 7 SP1 or Windows 8.")

Once the Explorer is powered up, three small, white LEDs on its upper surface light up; after data streaming begins, the pattern of lights changes to inform the user of the resolution of the incoming music file: one light for 44.1 or 48kHz files, two for 88.2 or 96kHz, and three lights for 176.4 or 192kHz. This is in marked contrast to those processors on which a single light is likely to correlate with mathematically related combinations of frequencies; eg, 48 and 96kHz.

Because the Meridian Explorer weighs just slightly more than a cookie, placing it atop any sort of "isolation" accessory seemed even more ridiculous than usual. So I didn't.

A few days after my review sample of the Meridian Explorer arrived, I set about running it in. In retrospect, given how little this changed its sound, the new converter didn't particularly need it, but I nevertheless enjoyed the time I spent using it to hear my favorite Internet radio stations, during which casual listening the Explorer's tonal balance and spatial presentation were almost indistinguishable from those of the similarly priced and sized AudioQuest DragonFly. (I was helped to that early conclusion by the fact that the two devices are also very similar in apparent output voltage.)


The first serious listening I did with the Explorer was to the classic bluegrass album Appalachian Swing!, by the Kentucky Colonels, featuring Clarence and Roland White on guitar and mandolin, respectively (AIFF ripped from CD, Rounder SS31). The Meridian was instantly impressive, with a sense of scale that was pleasantly big but still appropriate to the ensemble and their setting. The original recording is a bit light, but the Meridian Explorer retrieved from it almost as much timbral color as one might hope for. The same was true with the weight and color of Roger Bush's double bass—the Explorer was clear and unambiguous in portraying the pitches of individual bass notes, down to being coldly candid about Bush's dodgy intonation.

Subtle differences were apparent between the Explorer and the DragonFly, the former having considerably better channel separation. Although not as severely "two-channel mono" as, say, those early Beatles albums, Appalachian Swing! doesn't have a lot of center fill, a characteristic made all the more plain by the Meridian. Comparisons between the Explorer and the Halide DAC HD showed the latter to be a little meatier in the timbral sense—though one could, I suppose, turn that around and describe the Explorer as "airier." That said, I did prefer the richness of the Halide—which costs almost twice as much. All three products got across the essence of the White brothers' highly charged musical interplay, yet I dare say the Meridian was the most explicit, being clearly upfront about such subtle musical—not merely sonic—details as the bass lines that guitarist Clarence sneaks in behind brother Roland's mandolin solos.

Far be it from me to tell the players on Buena Vista Social Club (AIFF ripped from CD, World Circuit/Elektra Nonesuch 79478-2) that there's an overabundance of trebly percussion instruments in the opening measures of "Amor de Loca Juventud." That said, there was something in the sound of the Explorer that brought that quality to the fore. The Meridian wasn't bright, wasn't etched, and didn't lack bass, but there was a lightness—or a responsiveness to a lightness in the music, if you will—that highlighted those high-frequency overtones. The difference between the Meridian and AudioQuest processors was exceedingly slight in this regard: Even through the DragonFly, I found those opening bars a bit too mosquitoey, but the effect was ever-so-slightly more pronounced through the Explorer.

And yet—listening through the Meridian Explorer to Lee Feldman's brilliant "Do You Want to Dance?," from his Album No.4: Trying to Put the Things Together that Never Been Together Before (AIFF ripped from CD, Bonafide UM-130-2), I again heard a sound with a more silvery, more detailed treble range than through the DragonFly. Here, however, the slight distinction definitely favored the Meridian: The British converter made clearer the descending figure in the tremoloed electric bass, revealing a greater frisson of feeling.

Speaking of bass, the Explorer proved capable of communicating low-frequency tones with appropriately generous weight and power. The Meridian allowed just the right amount of force and purr to the double bass and bass drum in "Polly Come Home," from Robert Plant and Alison Krauss's Raising Sand (AIFF from CD, Rounder 11661-9075-2). The timpani that open the third movement of Mahler's Symphony 2, performed by Gilbert Kaplan and the London Symphony Orchestra (AIFF from CD, MCA Classics MCAD 2-11011), had fine attack and a degree of timbral richness in their decay that, while not the best I've heard from a USB DAC, was satisfying. Later in the same recording, the Meridian was more than satisfying in the way it communicated the sheer, monstrous weight of the assembled instrumental forces, organ and carillon included. Heard in concert, the ending of that symphony should leave one, if not in tears, then at least slightly misty; heard in my home, the Meridian did the job—which, at the end of the day, is the most important thing I could ask of it.

A brief mention is due of the Explorer's performance with headphones: a style of listening with which I'm less than experienced. My feelings belong in the file folder labeled "Musically Satisfying and Free from Gross Distortions, Although the Sound Was A Little More Opaque Than I Expected."

When it comes to inheriting the Earth, or at least that portion of it that wants perfectionist-quality sound from music files stored on computers, I think The Small are doing a damn good job of things this time around. Fonder though I am of analog playback, I take heart at digital audio's recent efforts in making products that normal people desire and can afford—a trend of which there is no finer example than the Meridian Explorer. It is robustly competitive in its price range, and although bettered by the considerably more expensive Halide, the Meridian is not embarrassed by it. And the choice between it and the similarly fine AudioQuest DragonFly may, for some, come down to nothing more mysterious than aesthetics, ergonomics, and the question of whether one wants a headphone jack or not.

Also as with the US-made DragonFly, I can't deny being impressed that the people who assemble the Explorer live and work in the same country as those who stand to profit from its sale.

A remarkably good addition to a burgeoning field—and an excellent value. Very highly recommended.

Meridian Audio Ltd.
US distributor: Meridian America Inc.
110 Greene Street, Suite 407
New York, NY 10012
(646) 666-0140

jaywillin's picture

i believe there are several companies that make aftermarket usb cables, with all the necessary connector types at either end of the cable, and at differing degrees of quality, when i had the explorer, i used an audioquest forest usb cable.

audioquest alone makes a few different models.

Hi-Reality's picture

How does the M2Tech hiFace DAC (same price but 384kHz/32bit!) perform compared to the Meridian Explorer? 

Does Stereophile plan to test the M2Tech hiFace DAC?

Another question: can either of these DACs drive a power-amp when connected directly (i.e. with no pre-amp)? 

Thanks for any feedback!

nicoch's picture


look like low latency  filter by on chip hardware pcm5102a  ...the chip dont have external filter pin, ie no meridian apodizin filter!


JR_Audio's picture

Yes, this looks like the 0.55 FS notch of the TI low latency digital filter. The Meridian apodizing filter should have had his notch at exact 0.50 FS.


John Atkinson's picture

nicoch wrote:
look like low latency  filter by on chip hardware pcm5102a  ...the chip dont have external filter pin, ie no meridian apodizin filter!

JR_Audio wrote:
Yes, this looks like the 0.55 FS notch of the TI low latency digital filter. The Meridian apodizing filter should have had his notch at exact 0.50 FS.
Thank you for the correction, guys. I have amended the text accordingly.

John Atkinson
Editor, Stereophile

nicoch's picture

Thanks you for Stereophile :)