Meridian Explorer 2 Portable MQA DAC

My first exposure to Meridian came in the form of the very interesting Meridian Prime headphone amp and DAC. I loved the look and sound of the Prime, but could never justify the price and wasn’t sure if it was an amp with a DAC thrown in or a fully-fledged flagship all-in-one. What I loved about it most though was the MQA decoding it is capable of, so when I had the chance to grab a secondhand Explorer 2 DAC (the Prime’s much, much smaller brother) I had to take the opportunity to get some portable MQA goodness.

Overview

The Explorer 2 retails in Australia for about $450 and offers a compelling feature set…

  • Meridian apodising filter – prevents distortion and harshness in digital audio
  • 3.5mm 2V fixed-level line out
  • 3.5mm headphone out (output impedance 0.47Ω)
  • Asynchronous USB (micro USB connection)
  • Up to 24-bit / 192kHz decoding
  • MQA decoding
  • Dual XMOS DSP with 16 cores and 1000 MIPS
  • Dimensions:  18mm x 32mm x 102mm (HxWxD)
  • Weight:  50g
  • Aluminium enclosure

Design & Compatibility

Casing & Connections

The Explorer 2 is one of the smaller portable DACs I’ve ever tried and while it’s not as small as something tiny like the DragonFly from AudioQuest, it stacks up favourably with most other portable DACs on the market. It’s a very sleek unit with a sand-blasted style aluminium casing and black plastic end caps. The elliptical cylinder is flattened on the bottom so it sits nicely on a desk and there are three flush mounted LEDs in the top of the unit to help identify sample rates. Other than that, the unit is a perfect cylinder of aluminium.

At one end of the Explorer 2 is a micro USB socket. Meridian chose to use a cable connection instead of direct connection to prevent physical strain on your computer’s USB socket and I think that’s a good move on their part despite the inconvenience of needing a separate cable and more space as a result. I’m personally not a fan of micro USB as a connector, but Meridian provide a nice short (and decent quality) USB cable so you don’t have to find your own.

At the other end of the Explorer are two 3.5mm sockets – one for headphones and one as a dedicated line-out. These are clearly labelled and well-spaced, but you can’t use them both at once because connecting the line-out disables the headphone out. I can’t help but feel better about having discrete connectors for variable vs fixed outputs because I feel like the fixed output can be greatly simplified if you’re not trying to include attenuation on the circuit to allow volume control. Generally speaking, a simpler circuit is a better circuit for audio so I appreciate Meridian’s design here and it seems to pay-off based on what I’m hearing when I use the Explorer 2 as a dedicated DAC (compared to say the DragonFly Red which has a single output for both fixed and variable use).

Operating Systems & Formats

The Explorer will work without drivers on a Mac and on Linux. On Windows you’ll need to download drivers, but the good news is that any recent computer operating system can work with the Explorer 2. Unfortunately, this versatility doesn’t translate to mobile devices – probably due to power consumption – so the Explorer 2 is strictly a portable computer DAC, stick to the AudioQuest DragonFly, Cozoy Aegis or similar portable DACs for mobile phone usage.

In terms of file formats, the Explorer 2 will comfortably handle any sound format other than DSD / DXD meaning that MP3, AAC, WAV, FLAC, etc. all up to 24-bit / 192kHz will work just fine. As a super added bonus, the Explorer 2 will also decode MQA audio, an exciting format that manages to pack super high quality audio into a file the size of a standard FLAC file! I’ll hopefully have a chance to write a detailed article about MQA and its wonders in the near future, but for now let me summarise by saying that MQA manages to remove some of the timing errors inherent to other digital formats and therefore recreates one of the best (if not THE best) quality audio reproductions I have ever heard. I’ll do some specific comparisons later in this review to see if MQA can lift the Explorer 2 beyond some more expensive DACs, but even if it doesn’t raise the Explorer 2 dramatically, it’s still a great feature in an excellent portable DAC.

One last comment on MQA… even though I absolutely love what I hear every time I listen to an MQA recording I am saddened to report that finding purchasable MQA recordings of common artists outside of Europe and perhaps the US is tricky. Hiresaudio.com have an amazing range of MQA albums for download, but most of them can’t be sold to Australia (and I assume other regions outside Europe / North America). zdigital.com.au will hopefully offer MQA audio in Australia soon, but currently the only reliable source of MQA tunes in this region is to pay for the top Tidal subscription. As a non-believer in streamed audio as the sole source of tunes (I like to own my own music library in addition to streaming), this doesn’t really suit me so, for now, MQA is an occasional treat rather than a regular delight.

Sound Quality & Comparisons

DAC Stage

I always find distinguishing DAC qualities to be a case of subtleties and nuance once you get above entry-level DACs. There’s no doubt to me that there is a significant difference between a basic onboard PC DAC and any half-decent external DAC, but once you start comparing reasonable quality external DACs, the differences become more and more obscure… but they are there.

As a DAC (i.e. fixed line-out only), the Explorer 2 is really excellent! I’m shocked to report that it stands up really well to even the Schiit Gumby! It doesn’t have quite the subtlety and layering that is the magic of the Gumby, but tonally and in terms of detail retrieval it’s very similar. The sound is clean and crisp, but remains musical and organic, never straying into artificial clarity, edginess or glare. Compared to the DragonFly Red, the Explorer 2 offers a sense of refinement and clarity that’s a slight notch above.

I’ll compare these DACs in more detail later, but the summary conclusion is that the Explorer 2 provides a clean and detailed sound while remaining musical and organic. In terms of overall quality it sits above the slightly cheaper, but mobile capable DragonFly Red, but below the MUCH more expensive Schitt Gumby (seriously, the Gumby is 10x more expensive!)

The staging from the Explorer 2 is very good thanks to its clean and natural sound. There’s a good sense of space in the stage and the width is also quite good – not top notch perhaps, but very good. Where the Explorer 2 falls a touch short is in depth. Compared to higher tier DACs, the Explorer 2 feels a bit compressed from the front to back of the soundstage. That said, it’s still on par or better than its competitors and definitely better than lower priced offerings. The general sound quality of the DAC in the Explorer 2 is outstanding and easily worth the investment for those short on space or needing a portable DAC.

DAC & Amp Combined

When using the Explorer 2’s built-in amp via the headphone output, the sound remains musical and warm – perhaps a touch warmer than the DAC alone. The sense of space is still quite good, but not at flagship levels (nor should it be for a device of this size and price). The soundstage seems to be further compressed by the amp compared to using the DAC alone so the result is a slightly thick sounding reproduction. It’s still very good for the price and size, but if you’re in a position to use a high quality external amp, the results can be improved. For example, the Explorer 2 paired with the FiiO E12 DIY is an outstanding portable (desktop) setup that easily rivals more expensive desktop systems.

A nice feature of the Explorer 2 as a DAC / amp combo is its volume control. The Explorer 2 has plenty of power for full size headphones, but I use it mostly for IEMs like the Noble K10s. The Explorer’s outstanding volume implementation means that I can control the volume down to suitably low levels to enjoy even the most sensitive IEMs without hiss or channel imbalance. This really helps the Explorer 2 to excel as a portable solution because a pair of good IEMs and the Explorer 2 can easily fit into a jeans front pocket with room to spare so if you’re tight for space this is a great solution.

Comparisons

All of the following comparisons are conducted using the combined DACs and amps of each device (where applicable).

Explorer 2 vs Cozoy Aegis

The Explorer 2 and Cozoy Aegis are very different beasts. The Aegis is tiny and powerful, but lacks a line-out function and is a bit finicky with volume levels and pops when changing tracks or starting playback. Other than that, both play hi-res audio and are prime examples of high quality industrial design. When it comes to sound there are some striking differences.

Both devices offer a rich and organic sound with very similar tonality and power output is quite similar too, but the Explorer 2 is head-and-shoulders better thanks to a greater sense of separation, space and layering in the sound. This could be in part due to the Aegis using a lower quality volume control that may be decreasing the dynamics of the sound, but no matter the reason, the difference is clear – the Explorer 2 is easily the better sounding product. Keep in mind, if you’re looking for a mobile compatible device, the Aegis is still a great option and the Explorer 2 is not an option for this type of assignment so don’t discount the Aegis, just know that the Explorer 2 is a better bit of kit if you’re looking for a computer-only portable DAC.

Explorer 2 vs DragonFly Red

The Explorer 2 and DragonFly Red are a closer comparison than the Aegis and Explorer 2. Both offer comparable sound as stand-alone devices (as a DAC only, the Explorer 2 is a little better), but there are differences in features. The DF Red will work with your mobile device and is super-efficient with power to save your battery life while the Explorer 2 won’t work at all with your mobile device. On the other hand, the Explorer 2 has an edge with its ability to decode up to 192kHz (only 96kHz for the DF Red) and offers MQA decoding (apparently coming to the DF Red soon via a firmware update).

In terms of sound, the tonalities are quite similar with a slightly drier note and a touch more top end energy coming from the DF Red. It’s a minor difference, but it leaves the Red sounding a little more dynamic and energetic and the Explorer 2 sounding a little more refined and smooth. I couldn’t say which is better out of these two – they’re just different.

Other than tonality, the Red is a slightly more intimate presentation with a smaller sense of space in the soundstage. It doesn’t feel cramped, but it’s more intimate. I honestly can’t split the two and that’s why I very happily use the DF Red with my phone every day on the train and then switch to the Explorer 2 for my laptop in the office. Both are outstanding devices with great sound and distinct strengths.

With MQA

As of 25th April 2017, the DF Red is still not MQA capable, but will be in the future based on articles I’ve seen around the internet. For now though, listening to MQA tracks separates these devices completely. The MQA-enabled Explorer 2 is a different beast when using MQA recordings. While the (for now) non-MQA DF Red sounds no different with MQA tracks, the Explorer 2 transforms into a flawless, flagship-level sounding device. What I mean is that the addition of MQA lifts the sound quality of the Explorer 2 far above the quality of standard lossless PCM / DSD sound. Suddenly, the Explorer 2 produces a soundstage with greater space, precision placement of sounds and a nuanced and detailed presentation that’s beguiling and engaging. The tonality of the sound is unchanged there’s just space and texture there now that wasn’t before.

Hopefully, the DF Red will enjoy the same remarkable transformation once the firmware update becomes available – I’ll try to come back and post an update when the time comes. For now though, if you can get your hands on MQA audio (including Tidal’s highest quality subscription), you might want to get the Explorer 2 over the DF Red just to enjoy the wonderment that is MQA playback.

Explorer 2 vs iFi Micro iDSD

This is a comparison of two very different devices. The iFi Micro iDSD is a do-it-all beast of a product with a powerful, but versatile amplifier, fully DSD capable DAC and all kinds of extra bells and whistles. The Explorer 2 seems outclassed on paper, but keep in mind how much smaller the Explorer 2 is, how much cheaper it is and the fact that it brings MQA decoding to the table…

On comparable tracks (PCM, non-MQA files), the sound from the two devices is quite different. The iDSD sounds a bit thicker than the Explorer 2 (probably due to the iDSD’s amp). Tonality is quite similar in terms of bass, mid and treble balance, but the presentation of the iDSD is much richer. While this makes for a slightly more relaxed listening experience, the Explorer 2 sounds more detailed and refined than the iDSD. It’s quite a distinct difference and I find myself enjoying the cheaper, smaller Explorer 2 when using the combined DAC / amp setups. Switching to an external amp, the difference is much less pronounced, but I would still give a slight edge to the Explorer’s sense of clarity and detail over the iDSD’s slightly thick sound.

With MQA and DSD

Switching to a DSD file (and returning to using just the headphone outputs from each device) brings things closer in performance so it seems the iDSD is a better DSD DAC than PCM DAC. The Explorer 2 is receiving a down-sampled PCM feed compared to the unaltered DSD feed going to the iDSD and the differences in sound are now fairly insignificant. With DSD files going to the iDSD I would have a hard time saying which of the two devices produces better sound so if you’re a DSD fan and have lots of DSD tracks, the iDSD might be a better option, particularly if you’re using the device as a DAC only with an external amp.

As you’d expect from the PCM-based comparison of these two products and my glowing reports on MQA playback with the Explorer 2, playing an MQA file lifts the Explorer 2 further above the iDSD. The iDSD got better with DSD files, but not to the level of the Explorer 2 when playing MQA audio. If pure sound quality is your focus, get an Explorer 2 and feed it MQA. If versatility is your focus then the iDSD can hold its own if you feed it DSD as much as possible (including upsampling PCM).

Explorer 2 vs Schiit Gumby

This is one of those completely unfair comparisons that I like to do every now and then. The Schiit Gumby is worth 10x the cost of the Explorer 2 so it’s really not a fair comparison… or is it?

When using standard files (i.e. not MQA), the Gumby shows easily why it holds the reputation as one of the best DACs on the market. The sound from the Gumby has a sense of ease and space that lifts it to a performance level above the Explorer 2. In defense of the Explorer, it’s sound is extremely good and the difference is incremental, not exponential. The Explorer on it’s own will impress most people, but when side-by-side with the Gumby in an A/B comparison it can’t keep up and nor should it. Things change a bit with MQA though…

With MQA

MQA might just be the holy grail of audio recording and playback. Simply adding the extra information provided by the MQA encoding allows the Explorer’s DAC chip to reproduce a sound with greater focus and realism than even the mighty Gumby. Honestly, if all my music were MQA, I might even choose an Explorer 2 over the Gumby because the sound quality is so close overall that the price and size of the Explorer 2 would win out.

To be more specific, what I hear when I compare the two DACs side-by-side when feeding MQA to the Explorer 2 (the Gumby receives the same stream, but sees it as a standard FLAC file) is that the tonality and presentations are very similar, but there is a focus and tactile nature to the sound from the Explorer 2 that’s just magical. The Gumby produces this type of sound with all files, but the Explorer 2 is perhaps slightly better once it gets MQA. The Gumby might still have an edge in some of the micro-details and textures, but the Explorer 2 is incredibly impressive when paired with an MQA feed.

Conclusion

After all this listening and comparison I’m left with one, solid conclusion – the Explorer 2 is an absolutely outstanding device! The only thing that prevents the Explorer 2 from achieving perfection is the fact that it can’t also fulfil mobile DAC duties, but perhaps that would require sacrificing some of the quality it’s capable of as a portable, desktop DAC. Without the addition of MQA audio I would still rate the Explorer 2 as a very good DAC, but I might give the edge to the DragonFly Red’s versatility. As it is though, the Explorer 2 can decode MQA and transforms into an absolute monster when given the right files (i.e. any MQA audio). If you’re in the market for a portable (or compact) desktop DAC, do yourself a huge favour and check out the Meridian Explorer 2!

Lachlan Fennen Written by:

Facilitator, training design consultant, blogger / writer and amateur photographer

4 Comments

  1. landroni
    April 30, 2017
    Reply

    Re MQA… On SBAF we’re somewhat more circumspect of what MQA, as a *format*, brings to the table above and beyond 96 kHz PCM. Most MQA releases thus far seem to come from different masters, and Meridian doesn’t look intent to make it easy to compare standard PCM to MQA releases. Many of the subjective reports thus far seem to point out to different mastering, and more specifically to masterings that indulge in the loudness wars, i.e. with significant compression of the DR.

    http://www.superbestaudiofriends.org/index.php?threads/tidal-adds-hi-res-audio-streams-with-tidal-masters-with-mqa.3662/page-6#post-109564

    Between this and that the ‘high-res’ part in MQA (i.e. above redbook) is lossy, as in based on perceptual encoding techniques, it is not obvious what MQA improves upon standard 96 kHz or quicker PCM… Other than, of course, DRM for the ‘high-res’ part, some bit budget efficiency (à la MP3) and — thus far — different and more compressed masters. I’m not sure any of these count as improvements from the perspective of the consumer.

    • May 17, 2017
      Reply

      Thanks for the info, Landroni – I always enjoy your perspectives. I’ll take a read and respond further…

      • May 17, 2017
        Reply

        It seems there is a disturbing lack of transparency and clarity around how MQA does what it does. My personal experiences from a purely subjective point of view are exceptional – I love what I’ve heard so far, but there are definitely some valid questions out there as to how well these benefits might translate across all albums. If it is truly a subjective application of sound processing then the results could vary dramatically depending on the engineers involved. I hope this isn’t the case and will continue to watch the MQA space with great interest…

        • landroni
          May 20, 2017
          Reply

          Yes, I definitely see what you mean. At the end of the day our subjective impressions and personal preferences are what really matter in this game.

          Torq seems to have played quite a bit with MQA, attempting to identify what is down to the format and what comes from other factors, and his appreciation gives me pause:
          http://www.superbestaudiofriends.org/index.php?threads/a-tidal-surprise.4243/#post-136415
          “In general what I’ve found listening to MQA-encoded content is that is exhibits a signature of increased brightness, a sense of increased detail, an apparent increase in the audibility of low-level sounds and the perception of faster transient response. On top of this, I am finding a generally faster onset of listening fatigue than I’m used to with the music in question. The more I’ve listened, the more I believe this is down to a combination of dynamic range compression (making low-level sounds more audible) and an artificial increase in brightness … but whether that’s because of MQA or because the ma[s]ter it was encoded from exhibited those traits, it’s impossible to say!”

          Dynamic Range compression is something I enjoy less and less, and since I started measuring the DR of my albums I’ve noticed that higher DR compression correlates with difficult to tolerate loudness (i.e. I need to lower volume by 15-20 dB, to make things bearable, from the nominal ~75 dB as calibrated using pink noise) and listening fatigue. At the same time increased brightness is also something I associate with increased fatigue from my Grado days (SR225i). And while immediately impressive, it’s not something that has worked well for me in the long term.

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