iFi Micro iDSD Black Label: In the Hands of a Non-Believer ​

It's been a good few weeks of my time back in Singapore, and in that time I've been back at trying my hand at all the new gear that I've missed out over the past half a year I was gone. In my new arsenal of testing equipment is the Micro BL, a unit that ifi has graciously granted me for review and subsequently for future review use(I was personally looking for a Micro BL to play around with long before the community representative contacted me).As most of my readers should be well aware, I'm primarily an IEM specialist and I hardly step outside this circle so this review will be from a perspective of an "agnostic" of source-end scaling rather than someone who rolls with tons of source gear (though make no mistake, I have my fair share of DAP experience as well). In this regard, the Micro BL isn't the one to prove to me that IEMs "scale" with power (as with every other DAP I've tried that is available on the market), but is still anuseful piece of gear to my work for other reasons.In terms of the technical nitty-gritty details, I shall defer to the venerable @earfonia and their ridiculously in-depth analysis . What I'll be writing about shall be mostly on the subjective listening and personal use side of things.I primarily use the Micro BL on Eco mode and Ultra Sensitivity due to the relatively low volumes I listen at (I typically average at 10 o'clock on the volume pot, dependent on the IEM used of course). As an amplifier, the Micro BL is very clean and extremely powerful, never distorting audibly except in the rare cases where the knob is maxed out. Though in fairness, by playing around with the different power and output settings (Eco/Normal/Turbo power settings with High/Ultra/Off IEMatch settings) you can adjust to a setting that gives you a good volume at 12 o'clock with virtually any IEM.The signature of the Micro BL is, on a scale of exciting to sterile, strays pretty far into the exciting camp of things (perhaps too far for some); and on the warmth scale, doesn't seem to exhibit too much warmth in its presentation if any at all. This makes the Micro BL a pretty energetic and textured "colouration" to the paired transducer, which works to the advantage of some IEMs but not to others. Most of my gear are pretty laid back, warm and/or bassy (see: UE18+ gen 2 or N8) so this sort of "opposite synergy" is my kind of match. On the flipside, the Micro BL would make things like the Etymotic ER4 or Hidition IEMs even more intense to listen to so it's certainly not a magic make-everything-better button.That said, this hobby is all about preference so someone who's looking for extra definition and texture in their setup could certainly enjoy the Micro BL out of their already-sterile transducers. It really is all about the type of synergy that you prioritise as opposed to a source being always objectively better.Versus the iFi Nano iDSD Black Label which I've bought mostly for the IEMatch function as well as something to use off my PC, it is a lot cleaner and more textured. The Nano BL is rather warm and smoothed over, which does make for a nice and non-fatiguing listen but also doesn't exactly have a lot of technical chops. The other plus point for the Micro BL is the volume pot of the Nano BL has massive imbalance at lower settings, which is quite a problem for low volume listeners like me. Having the option to limit the power output for a less sensitive volume knob is a pretty big pro that would be hard to overlook.The Micro BL comes with a lot of extra bells and whistles that could be construed as "gimmicks" to those who just want a plug-and-play experience. For my uses, I find myself flipping switches and swapping outputs very often during testing and measurements, so I would consider at least most of them as very useful features.The digital filter option would be one of those features that I'd consider as semi-useless, though it's still nice to have the option to swap them whenever you want. The Micro BL sports three filters; the "Standard" filter (also called the "Measure" filter in other ifi devices, it's basically a linear phase filter), the "Minimum Phase" filter (self-explanatory) and the "Bit-Perfect" filter. I always actively avoid any linear phase filters in any DAC I use so it's pretty much a toss-up between minimum phase and bit-perfect for me. The main difference I could really reliably hear was that the bit-perfect filter seems to blunt note attack slightly, which couldhelp with reducing the intensity of the Micro BL's signature but was rather off-putting to hear. Thus I usually defaulted to minimum phase.The bass boost (or should I say, XBass+) is a pretty sweet feature and was actually one of the main highlights for one of the people who tried my Micro BL. It is a rather potent boost but also very well done, not too much midbass emphasis and adds a lot of extra subbass rumble. It's permanently switched on for my desktop HD800 setup and is a nice guilty pleasure for my already bassy IEMs.Then there is the 3D+ switch which I have almost zero desire to use and has been generally regarded by my peers as "bad". The Micro BL's 3D+ switch apparently increases crossfeed but all I really hear is that the overall sound gets brighter and harsher and that's about it. And on a side-note, the switch issatisfying to flip.On that note, the switches that aren't the XBass+/3D+ feel rather fragile and that's a little disappointing. I've actually had the IEMatch switch pop off on accident once. There also doesn't seem to be a tactile enough click per setting so there might be an issue with setting it to options in the middle of the switch given enough wear and tear.Saving the best for last, the multitude of options to limit power and output impedance. It's a pretty nice feeling to go from a Campfire Andromeda to a AKG K1000 just by flipping a few switches. Too often do I run into the problem of powerful amplifiers beingtoo sensitive for IEMs and/or having too high a noise floor, or IEM-specific amplifiers being unable to drive even basic headphones. Speaking of Andromeda, the Micro BL also lets you play with impedance-sensitive IEMs with the IEMatch options (~0.5ohms on direct mode, ~4ohms on high sensitivity mode) along with the added function of killing hiss. Again, the Micro BL is unable to prove to me the scalability of IEMs by power, but it is an absolute treat by sheer versatility alone.From the perspective of a measurement guy, the Micro BL helps me get that extra SPL out of difficult headphones, which is extremely useful especially in a shop environment. Any more power and I'll be driving them off desktop setups, which then goes against the point of my new measurement setup As another plus point, you can use it as a power bank whenever your phone or DAP runs low on battery so that's cool. Saved me quite a few times now.To reiterate, I don't usually review source gear so my apologies if I'm not as critical of flaws than I usually am with my IEM reviews.In my case it's less about how good the Micro BL sounds but rather the flexibility and power it provides to me. For what it does regardless of sonic quality (which it still has in spades!), it presents a value that I find is currently unmatched in the portable DAC/amp market.