Overview: My intent when I started this was to do a review of the iFi Audio Micro iDSD Black Label, with very high-level comparisons to Chord’s Mojo and the AudioQuest Dragonfly Red and, maybe, a Schiit Modi MB for good measure (and as a well-known reference point). A few things have happened since then … First, Tidal started streaming MQA content, and I picked up a Meridian Explorer 2 to have a cheap/convenient way to explore MQA a bit. This proved to be quite the diversion (more about that in another thread), but on top of the MQA aspect the Explorer 2 turned out to be interesting enough to warrant more commentary. So, I figured I’d include it in my comparison with the iFi unit. Next I picked up a Geek Out V2+ Infinity, a unit I’d been wanting to hear for a while but had never gotten my head around actually managing to buy. A little time with this meant it wouldn’t really be cricket to not include this in the comparison as well. So, what was going to be a relatively focused review is now a five-way portable DAC/amp comparison, with a couple of extra bits in for reference/comparison: LH Labs – Geek Out V2+ Infinity Chord - Mojo iFi Audio - Micro iDSD Black Label Meridian - Explorer 2 AudioQuest - Dragonfly Red The extra bits being Schiit’s Modi multi-bit and the Apple Lightning to 3.5mm dongle. This has resulted in this being a rather long write-up (single-post-breakingly long) and, as a result, I’m going to break it up into several posts, over a couple of days. The first (this one) will cover the overview and core information for the above units. The second will be a focused on sound and results, and will likely received additional “color commentary” - this will be the most useful I expect. The third will cover comparisons to the Schiit Modi Multibit etc. And a final post will include some comparisons to other players/DAPs. Headphones/IEMS Used: Most of my critical listening on these units was done with the Shure SE846 and original ER4-S, with a quick round of impressions using the Campfire Audio Vega, in keeping with their nominally portable-bias. However, I also let them loose on my full-size cans to determine broader relevance and capability. And to maintain as much relevance to as many SBAF members as possible, I used the HD-650 as a baseline there, but I’ll include notes on how things faired with more demanding cans as well and as appropriate. About the Units in Question: I’ve listed these in order of descending price. Prices are based on manufacturer’s current claims so it’s entirely possible that they will differ from what you’ll actually pay. Any comments relating to price vs. value are based on these MSRP figures. Commentary here will address features, ergonomics, packages, and other basic information, but will not cover how they sound; those comparisons get their own section. LH Labs Geek Out V2+ Infinity ($649): The basic features include a high-quality ESS Sabre-based DAC coupled with an amplifier offering multiple levels of gain, yielding different potential power-output levels (100 mw, 450mw and 1000mw), three different digital filters, balanced (3.5mm TRRS) and single-ended (3.5mm TRS) outputs, independent micro-USB signal and power connections and a decently sized internal battery. I’m not actually sure about the pricing on this. But then, beyond the crowdfunding campaign, and the occasional appearance on Amazon, I was never able to figure out how I was supposed buy a specific version of one (short of buying used, which is what I ultimately did). The finish is, honestly, extremely poor. It looks awful and doesn’t feel much better. I say this not to knock the unit, just to set proper expectations if you buy one. The build is not going to impress you, but knowing what to expect might save some disappointment. Or, in other words, you don’t buy this unit for how it looks. Note: Newer units have a different finish entirely, but I've not seen one of these in person so can't comment further. Chord Mojo ($599): Initial impressions are of serious solidity coupled with quite polarizing styling (which will be a Marmite thing for most people). Spending a bit of time with the unit brings about the rapid realization that it’s just the heavy metal shell that gives the feeling of outward solidity. Actual sockets are, apparently, just soldered to the internal PCB. Despite the heavy metal casing, Mojo is surprisingly susceptible to EMI. For a device that is intended to be used with a phone, this is unfortunate. While the degree of interference is dependent on what radio bands your particular phone is using and, as a result, can change markedly depending on where you’re using it, there’s a good chance you’ll need to put your phone in “Airplane” mode if you want a clean listening session. It’s curious to note that none of the other units I compared here exhibited these issues at all. Also, I think this has the worst USB implementation I’ve come across. It results in frequent dropouts when playing multi-rate DSD via every macOS machine I’ve tried and some Surface devices, and seems excessively affected by electrical noise on the USB connection. Think twice before buying one of these if you run an Apple machine and want to play DSD. There are three input options … USB (of course), a 3.5mm COAX S/PDIF connection and a standard TOSLINK optical S/PFID input. And then you get two, identical, 3.5mm SE (TRS) headphone outputs. Volume control is on the DAC itself and is both controlled, and indicated, by two big translucent balls. You press them like buttons to actuate them, and they light-up to show status. The power-button does the same thing and is used to indicate on/off as well as the current sample rate/mode of the data it is playing. High-bit rate PCM (768 KHz) and quad-rate DSD (DSD256) are supported, though DSD is only accessible via DoP (even using the native ASIO driver for Windows). This unit runs quite warm and, well, downright hot if you play and charge at the same time. This is normal and not a cause for concern (well, not about whether its “supposed” to be like this at least). Battery life is quoted at eight hours, but six is closer to my experience … a bit less with low-impedance transducers. Charging is supposed to take four hours. It’s usually five for me. And most of the time it takes ALL of that time even if I’ve only run it for an hour. Some units exhibit what amounts to “coil whine” when charging … this is NOT audible through the headphones and is a physical thing … supposedly fixed in all new units, but mine definitely does it. Doesn’t bother me, but it does some, so be aware. iFi Audio Micro iDSD Black Label ($549): This thing is huge. Twice the size, effectively, of Mojo … if not quite twice the weight. While it’s actually a bit more convenient to use with a phone than Mojo (due to a clever cable arrangement on the iFi unit), and doesn’t exhibit the EMI issues that Chord’s unit does, it’s still a bit impractical as an on-the-go solution. Though if you did use it like that, you wouldn’t be limited in what headphones you could drive! It offers a built in Octo-Rate DSD (DSD512)/768 KHz PCM capable Burr-Brown based DAC, the outputs of which can be accessed via RCA jacks at line level (bypassing the amp) or as a pre-outs. There are three selectable digital filters for the DAC section. There’s a headphone amplifier with three gain settings and enough grunt to drive the Abyss or LCD-4 and this can either feed straight off the internal DAC or it can take an external input (via a 3.5mm TRS jack). It’s quiet enough to drive the most sensitive IEMs without issue and has a built in “iEMatch” capability that improves compatibility there still further. This allows for impedance matching/attenuation to get the best out of highly or ultra-sensitive transducers … and it can be turned off completely too. It is effective enough that if you set it to Ultra, you get a totally silent background even on Turbo (high) gain into SE846. Then there is a cross-feed circuit called 3D+ and a bass-enhancement/boost function, both of which have their uses, but I’ll come back to in the “how does it sound” part. Inputs are USB, COAX S/PDIF and mini-TOSLINK S/PDIF, there is a variation of iFi’s “purifier” technology on the inputs, and it can be used as a USB -> S/PDIF COAX DDC (and does a decent job of it too). Oh, and it has a comparatively huge internal battery that’ll power the unit for about 12 hours and that can be used to charge any other USB device. And it’ll run either off that internal battery (even when connected to a USB source, allowing it to be isolated from USB power noise) or can be fully USB powered. Flexibility and capability are major factors with the iFi Black Label. One unmissable issue, which seems to be quite commonly reported, is channel imbalance at low-volume settings. While by no means a unique thing for units using an actual analog potentiometer in this role (this is the only unit in this comparison that does), it is the worst example of such imbalance that I’ve seen. Even driving the Fostex TH-X00 I am at almost 10:00 on the dial before it is completely gone, and at initial switch-on one channel is audible while the other is silent. Battery life and charging times are essentially right where iFi claims they are. Meridian Explorer 2 ($199): This is an outwardly simple device. One mini-USB 2.0 input, and two 3.5mm outputs … one variable to drive headphones and the other fixed-level as a line-level output. Beyond that it’s small, elegant, nicely finished, and sports three LEDs that indicate what mode and sample rate it is currently operating in. This is the only unit that currently supports MQA decoding, although the AudioQuest Dragonfly units are supposed to get this by way of a firmware update any day now. Whether you care about MQA or not, it’s really the only distinguishing feature of this unit Input supports PCM only at bit-rates up to 24 bits/192 KHz (though it can handle MQA streams that contain high-resolution folded data). There is no DSD support. This is the only device here that will not work directly out of an iPhone. I am sure the usual “powered hub” trick will work, though I haven’t actually tried it. AudioQuest Dragonfly Red ($199): Tiny, convenient, and even simpler than the Meridian Explorer 2. There’s a standard USB connector on one end and a 3.5mm TRS SE connection on the other. It offers PCM decoding for files up to 24-bit/96 KHz and, in the near future, it will gain MQA high-resolution decoding via a firmware update. Output power is quite reasonable … more than enough for any IEM I can imagine, including the not-very-efficient original Etymotic ER4-S, but struggling a bit if you wanted to run HD-650 off it. Not bad with TH-X00, but not ideal either. This is really designed for use with phones and laptops. In the former category, integration and behavior with iPhones and iOS is hassle free and works exactly as you would expect it to. All you need is the Apple Camera Connection Kit (cable) and you’re in business. With Android you should plan on using UAPP, as there are myriad reports of issues controlling volume on the Dragonfly and not being able to get it loud enough with many Android phones/builds. Apple Lightning to 3.5mm Dongle ($9) If this is relevant to you, you have one already. And it’s cheap enough to buy one for each headphone and just leave it connected to the cable. Compared to the native output on my former iPhone 6S this is better behaved with high-sensitivity low-impedance IEMs. In particular, with my multi-driver BA IEMs, it is noticeably more tonally even in its presentation and bass is tighter and more coherent. If you’re using something like the Vega or SE846 straight out of an iPhone 6S, you’re probably better off adding one of these adapters and bypassing the built-in jack. Headphone/IEM Matching - Power and Output Impedance: Excepting the Apple Lightning Adapter, which I’d reserve for use with IEMs/ear-buds or super-efficient cans (and I’d skip trying to use it with the original ER4-S), all of these units have anywhere from reasonable to serious power. Beyond that, any of them will work with things like the TH-X00, though the Dragonfly and Explorer 2 are hitting their limits before you’re in to serious volume with, say, the HD-650 and dynamics and control suffer there too. Raw numbers follow, taken from manufacturer specs where available and roughly measured when not (they’ll be in the ballpark if not definitive): Mojo, iDSD and GOV2+ Inf can all drive everything shy of the Abyss and LCD-4 with no particular problem, though with the HD800S the Mojo is not as convincing as the other two. Balanced output from the GOV2+ Inf can drive both the LCD-4 and Abyss, but I don’t think you’d want to do that very often. The iFi Micro iDSD BL does have the grunt to drive both of those headphones with useful authority – it’s not the last word in control but it’s the only unit here that I can honestly say you could use, regularly, with either of those cans.