• Meridian Explorer USB DAC Review

    At the 2013 Consumer Electronics Show Meridian very quietly and behind closed doors introduced a new pocket-sized USB DAC / headphone amplifier named the Meridian Explorer. I was very excited by the external and internal look of the Explorer. The extruded brushed aluminum enclosure and the six layer circuit board containing giant Nichicon caps, an XMOS L1 processor, and audiophile grade components throughout were extremely impressive. The specs were also superb. Notably the asynchronous USB input, support for all popular PCM sample rates up through 192 kHz, fixed and variable analog output, optical output, and digitally controlled analog volume attenuation. I declined the offer to listen through the Explorer in the Meridian suite because the conditions were less than good. The ambient noise, unfamiliar headphones, unfamiliar music, and limited time wouldnít have helped me develop an accurate first impression. Thus I flew back to Minneapolis and awaited the Explorerís arrival. My first impression of this $299 DACís sound quality in my system was excellent. Throughout the review period I compared the Explorer to a $249 competitor by listening through my Ultimate Ears 11 Pro, Etymotic ER4-P, and Sennheiser HD600 headphones. As each listening session passed I liked the sound of the Explorer even more. The Meridian Explorer has entered this market segment on top and is definitely the portable USB DAC to beat.











    Meridian Explorer


    The Meridian Explorer is a USB digital to analog converter, headphone amp, preamp, and digital to digital converter. On the outside the, 1.76 ounce 4.0 x 1.25 x 0.7 inch, Explorer looks and feels much like the AppleTV silver remote. The Explorer features three LEDs on the top. The LEDs indicate the currently playing trackís speed as 1x, 2x, or 4x. One LED illuminated indicates 1x sample rates of 44.1 or 48 kHz. Two LEDs illuminated indicates 2x sample rates of 88.2 or 96 kHz are being played. When all three LEDs light up the Explorer is playing 4x material at 176.4 or 192 kHz. The bottom of the Explorer has two important items. First it identifies England as the location of the Explorerís design and manufacturer. Thatís a big deal, especially for a $299 product of this caliber. Second, the tiny feet or platform combined with the rubberized label provide an ever so small amount of friction. This friction is really nice in that a right side up Explorer doesnít slide around as easy as the device would if it were a complete oval with brushed aluminum all around.

    Each end of the Explorer is covered by moulded plastic end caps. One end features a USB mini type B input. This input is powered by a computerís USB port at a nominal 5V at <500mA and is Class 2 USB audio compliant. Meridian elected to require a USB cable connection rather than build a protruding USB A type connector into the product. I see a few pros with this approach such as less stress on the computerís USB port, ability to use different USB cables, and I donít have to worry about blocking an adjacent port on my laptop because of the DACís size. During the review I used the included 6.5 inch USB cable and a two meter type A to mini B Wire World Silver Starlight cable. The Explorerís USB implementation uses the class leading XMOS L1 processor. The XMOS platform is my favorite because it simply works. The Explorer operates asynchronously with low jitter crystal oscillators providing the master clock source. Asynchronous implementations are becoming standard but no less critical. The other implementation called Adaptive USB can be inferior due to its lack of master clocking and lack of flow control for the incoming data stream. The asynchronous USB implementation in the Explorer is designed to handle both clocking and flow control.

    The opposite end of the Explorer features three outputs via two ports. One port is solely for headphones with a 3.5mm jack and discrete variable analogue headphone output (130mW into 16Ω). This variable output is a 64 step digitally controlled analog volume control similar to the AudioQuest DragonFly. The computerís master volume control is what attenuates the analog signal from the Explorer. This is very nice on a Mac laptop where the volume Up/Down/Mute keys or menu bar slider can be used to control the analog volume of the DAC. The second 3.5mm port on this end of the Explorer is a combination 2v RMS analog line out and an optical digital S/PDIF output requiring a mini TosLink to TosLInk cable. Both the analog and digital outputs are programmed without volume control from the factory. Also from the factory, the optical port is limited to a top sample rate output of 96 kHz. Quad speed material at 176.4 and 192 kHz is down sampled before being output via mini TosLink. Readers should note downsampling does not occur with 4x material on the analog outputs.

    Astute Computer Audiophiles likely noticed I used the phrase, ďfrom the factoryĒ in the previous paragraph when describing how the Explorer is programmed. I used those words to hint that the Explorerís configuration is not set in stone. One of the best features of the Meridian Explorer is the ability to customize the product to oneís own needs through simple firmware updates. Most people will accept the factory default configuration and be on their way to sonic bliss. Others can simply run the forthcoming Meridian application to change the deviceís firmware in less than ten seconds. At the time of this review the Meridian application was still a work in progress. However, I received instructions from the Meridian mothership in the UK on how to use the Terminal app in OS X to change firmware. The ability to switch backward and forward between predefined features sets is brilliant. During the review I changed the feature set of my Explorer to output 4x sample rates of 176.4 and 192 kHz via its optical digital output. I tested the output for bit transparency through the Berkeley Audio Design Alpha DAC and it passed without issue. As a test I switched between a couple different firmware builds, testing playback after each switch, without a single issue. After the Explorer is publicly launched Meridian plans to release a set of feature firmware images together with its simple OS X and Windows apps that enable users to choose between images at the push of a button. In addition to the 4x sample rate support via optical output Meridian will release firmware images that increase the flexibility of the Explorer well beyond any other product in its class. CA readers familiar with firmware updates of yesteryear know all to well how easy it is too brick a piece of hardware. According to Meridian the Explorer is brick-proof because an unsuccessful upgrade will cause the unit to failover to the default factory image stored in protected memory space. Meridian even went as far as suggesting the firmware update process can be interrupted by pulling the USB cable or resetting oneís computer without causing any harm to the Explorer.

    Internally the Meridian Explorer is something to behold. A pocket-sized DAC with six layer circuit board full of audiophile grade components and direct coupled outputs for $299 is something this wonderful hobby of ours has never seen. The detailed image below displays all the goodies such as Nichicon caps, linear regulators, XMOS processor, discrete audio clocks, and the PCM5102 24/384 kHz DAC.




    Using the Meridian Explorer


    I used the Meridian Explorer in two main capacities, as a headphone amplifier and as a DAC. I tested the Explorerís ability to convert digital USB input to digital TosLink optical output but only to make sure the unit worked as described. Before the firmware upgrade the digital output of 4x material was down sampled to 2x and after the upgrade all material from 1x through 4x was output bit transparently via TosLink optical.

    As a DAC / headphone amp the Explorer was terrific. I used it with my 15Ē MacBook Pro retina, OS X 10.8.2, Ultimate Ears 11 Pro, Etymotic ER-4P, and Sennheiser HD600 headphones. I tested the Explorer with iTunes, iTunes + Amarra, and Audirvana Plus. In this configuration all three pairs of headphones sounded excellent. The ER-4P and Explorer make a great combination. I ran through my usual playlist of music I know well and didnít experience any fatigue related to the sound. The Explorer appeared to have endless power and the ability to drive the Etymotics through the sound barrier. My go-to album for acoustic guitar and sonic decay is Ottmar Liebertís One guitar at 24 bit / 96 kHz. The Explorer / ER-4P combo reproduced this album very well with tight plucks of the strings and good decay. The decay could have been better, but Iíve yet to hear better from device anywhere near this price. Randi TytingvŚg's Red or Dead track as well as Ray LaMontagneís God Willing The Creek Donít Rise album sounded really smooth and silky with that last bit of detail somewhat glossed over. My favorite Nat King Cole album The Very Thought of You was a pleasure to listen to over and over. Natís vocals were to die for and the signature sound of Capitol Studios came through in all its glory. I could have sat at my local tea shop all day and listening to the entire Analogue Productions remasters of Nat King Coleís catalog through the ER-4P and Meridian Explorer. Switching off to the Sennheiser HD600s revealed a different but equally as impressive side of the Explorer. The silky smoothness was reduced just a tad in favor of a skosh more detail. I sense there may be more detail in the Explorer just waiting to be released under the right conditions. Toward the end of my listening sessions with the HD600 headphones I was in the mood for one of the best Rap albums of all time, N.W.A.ís Straight Outta Compton . This album is no audiophile standard but it contains music that I love from some of the most influential artists ever from the Rap genre. The opening three tracks Straight Outta Compton, F**k the Police, and Gangsta Gangsta comprise a hat trick of Gangsta Rap. The HD600 headphones were tightly controlled by the Explorer even under the most punishing bass conditions. I had the volume at 100% for some of the listening and was at my loudness limit. The Explorer couldnít play any louder but my ears couldnít handle anything louder. The DragonFly appears to play louder with the HD600 but the sound quality is gone at this volume level. Through the Explorer the bass was very prevalent but well controlled. Contrast that to the DragonFlyís bass that was louder but much muddier and looser. The DragonFly lacks the control of the Explorer not only at high volumes but in most listening scenarios.



    Listening through the Meridian Explorer as a DAC only connected to my main system via its analog line out produced a very similar experience to headphone listening. The sound was very different as one would expect when switching from headphones to a full two channel stereo system but the qualities of the Explorer remained the same. The last bit of detail wasnít quite there although the smoothness and liquidity were appropriately present. This was never more apparent then listening to Randi TytingvŚgís Red or Dead. Her vocal wasnít as piercing as Iíve heard through my system in other configurations. Ben Harperís By My Side and Glen Hansardís Rhythm and Repose, both at 24/96, sounded very good. Again I didnít hear the ultimate in texture or detail but I was listening to the music. Thatís what really counts. The Explorer had my attention the entire time.

    Comparing the $250 AudioQuest DragonFly to the $299 Meridian Explorer reveals real differences readers can use to make purchasing decision. Nearly twice as long and twice as wide the Explorer is much larger than the DragonFly. Both products are still pocket-sized but if size is most important (large or small) the decision should be easy. The Explorer features optical digital output, reprogrammable feature sets, and support for 176.4 and 192 kHz. The DragonFly offers none of the aforementioned features. The Explorer has a detachable USB cable while the DragonFly has a captive USB type A connector. The Explorer requires drivers on Windows because it supports 4x sample rates. The DragonFly is plug and play. The sonic differences between the two devices are not factual like the specifications. In my listening sessions the Explorer has a larger sound stage, more control, and an overall better sound. The DragonFly is the 2012 Computer Audiophile Product of the Year. If the Explorer would have been released in 2012 I would have very likely given the award to Meridian. The pace at which digital components improve and change can be frightening for some and exciting for others. Iíve never been more excited about being an audiophile than I am now. $299 for a great product from a great company was unheard of a few years ago. Nearly everyone can afford high resolution playback at high quality with the Meridian Explorer.


    Conclusion

    Meridian has outdone itself with the $299 Explorer USB DAC / headphone amplifier. Externally the Explorer exudes quality in both look and feel. Internally the design is excellent with a sophisticated six layer board, audiophile caps, and the XMOS USB chip. Functionally the Explorer does it all. A pocket-sized DAC capable of high resolution playback up through 24 bit / 192 kHz, user switchable firmware for customized feature sets, and great sound quality. The hat trick of external elegance, internal sophistication, and superior sonics put this product head and shoulders above the competition and places it on the CASH List . The Meridian Explorer is a product computer audiophiles will want to be seen with at the local coffee shop.




























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    Product Information:



    • Product - Meridian Explorer USB DAC
    • Price - $299
    • Product Page - Link












    Associated Equipment:













    Comments 106 Comments
    1. AudioDoctor's Avatar
      AudioDoctor -
      We must go to different coffee shops Chris, all my favorite haunts are too loud either because of the music or the people, and sometimes both. I could never ever listen to music in any of them, especially with open back headphones.

      Am I right that this would not work as a DAC in a full size system, only a USB to Toslink converter, or would a headphone jack to RCA jack cable work?
    1. The Computer Audiophile's Avatar
      The Computer Audiophile -
      Quote Originally Posted by AudioDoctor View Post
      We must go to different coffee shops Chris, all my favorite haunts are too loud either because of the music or the people, and sometimes both. I could never ever listen to music in any of them, especially with open back headphones.

      Am I right that this would not work as a DAC in a full size system, only a USB to Toslink converter, or would a headphone jack to RCA jack cable work?
      Pick up a pair of IEMs that block out 26dB of external noise and all is right with the world :~)

      I'm guessing you skimmed over the review. The Explorer has three outputs, headphone, line out, and toslink. It works well in a full size system.
    1. jhwalker's Avatar
      jhwalker -
      I want one right now - exciting times in portable audio, for sure!
    1. wisnon's Avatar
      wisnon -
      It costs the same as the iFi IDac (Sabre chip), so there are real choices out there.
    1. Jsmith's Avatar
      Jsmith -
      Chris, I would appreciate it if you can expand upon a topic of the use if the Wire World USB? Did you notice any sonic difference between this and the stock cord?
    1. DKennedy's Avatar
      DKennedy -
      My Explorer shows up next week. Can't wait to get my hands on mine! Will be very interesting to see if Android will support the piece..

      I listened to it last week, and compared it to a few $1,000+ DACs as a line level out. None of the Sabre implementations I compared it to came close. While I liked the Meitner MA-1 more in my system, the Explorer compared VERY favorably. Anyone looking for a new DAC, line level or headphone, would be missing out by at least listening to one.
    1. wisnon's Avatar
      wisnon -
      Doesn't it draw power from the PC?

      If so, I dont see why $1,000+ Dacs should be shaking in their boots. Now if you have a power isolater in there...
    1. The Computer Audiophile's Avatar
      The Computer Audiophile -
      Quote Originally Posted by wisnon View Post
      Doesn't it draw power from the PC?

      If so, I dont see why $1,000+ Dacs should be shaking in their boots. Now if you have a power isolater in there...
      Most DACs use USB bus power.
    1. wisnon's Avatar
      wisnon -
      Not if you use a USB converter to Spdif like the OffRamp/JKeny, or if you put an isolator in-between though.

      I see no protection from the PC at all here, so an after market unit should help a lot.
    1. The Computer Audiophile's Avatar
      The Computer Audiophile -
      Quote Originally Posted by wisnon View Post
      Not if you use a USB converter to Spdif like the OffRamp/JKeny, or if you put an isolator in-between though.

      I see no protection from the PC at all here, so an after market unit should help a lot.
      Hi Wisnon - Let's not derail the comments here, but what you're describing isn't using a USB DAC rather an S/PDIF DAC.
    1. labjr's Avatar
      labjr -
      Nice review!

      Looks like a Bic lighter!

      No DSD support on a portable device yet. I didn't really expect Meridian to be the first to do it. And looks like the PCM1502 has no DSD support.
    1. MikeJazz's Avatar
      MikeJazz -
      Hello Chris!

      Great addition to the reviews, I just learned about this product today and you already had a review!
      And I was considering buying the DragonFly...I guess I must reconsider.

      This is very interesting!
      One question, if we use the higher resolutions on the Explorer as a Digital Interface (optical digital as 176.4 and 192 kHz) what will be the practical use...
      I thought the toslink interface was limited to 96, and I think we find this limit in most dacs...or not?
    1. AudioDoctor's Avatar
      AudioDoctor -
      Quote Originally Posted by The Computer Audiophile View Post
      Pick up a pair of IEMs that block out 26dB of external noise and all is right with the world :~)

      I'm guessing you skimmed over the review. The Explorer has three outputs, headphone, line out, and toslink. It works well in a full size system.
      Yeah, sorry about that I was interrupted midway through it and again during my reply. So you connected it via a 3.5mm mini headphone jack to RCA cable I see.
    1. The Computer Audiophile's Avatar
      The Computer Audiophile -
      Quote Originally Posted by MikeJazz View Post
      Hello Chris!

      Great addition to the reviews, I just learned about this product today and you already had a review!
      And I was considering buying the DragonFly...I guess I must reconsider.

      This is very interesting!
      One question, if we use the higher resolutions on the Explorer as a Digital Interface (optical digital as 176.4 and 192 kHz) what will be the practical use...
      I thought the toslink interface was limited to 96, and I think we find this limit in most dacs...or not?
      Hi Mike - 96 isn't the limit as evidenced by my bit perfect test at 192 and 176.4. It all depends on the receiving device.
    1. Snowmonkey's Avatar
      Snowmonkey -
      Ahhh, the Dragonfly - yesterday the darling of the audiophile world, today a squashed bug on the windscreen. Sic transit gloria.
    1. John H. DarkÝ's Avatar
      John H. DarkÝ -
      Quote Originally Posted by Snowmonkey View Post
      Ahhh, the Dragonfly - yesterday the darling of the audiophile world, today a squashed bug on the windscreen. Sic transit gloria.
      Nailed it.
    1. Old Listener's Avatar
      Old Listener -
      Chris,

      Your review mentioned that the Explorer DAC required a driver for use under Windows. I didn't see any discussion of driver installion and performance. Did the driver installation go smoothly? Has operation under Windows been troublefree?

      Bill
    1. firedog's Avatar
      firedog -
      Meridian Explorer USB DAC | AudioStream

      Another positive review
    1. MikeJazz's Avatar
      MikeJazz -
      I guess reply to articles are buggy...I know Chris has replied to my last message but cannot see it here...(was visible in "what's new" page)....
    1. felix's Avatar
      felix -
      It could make sense to use a Meridian Explorer USB DAC instead a Musical Fidelity V-Link 192 as a high quality USB to S/PDIF converter without taking into account de DAC or the headphone amplifier? Of course with the 4x sample rate tweak. The reason i ask is before the Meridian i was planning to buy a Musical Fidelity & a DragonFly. But at least in theory the Meridian should be a perfect replacement for both & much cheaper. But i don't want to skimp on audio quality for the USB to S/PDIF converter.