I guess I’ll throw some thoughts in here to kick things off. I said a few words about this unit in the main iFi-brand thread. I’ll elaborate a bit on that here.
I bought the iFi Audio Micro iDSD BL a while back to leave at my fiance’s place and still have a reasonably powerful, flexible, good-sounding option to listen there. In doing so I wound up comparing it to a whole bunch of other similar DAC/amps, dongle-DACs and DAPs … but I’ll limit my comments here to those focused on the Micro iDSD BL’s signature, features and performance.
Picture for provenance …
Features:
This thing is laden with features. It can be used as a purely analog amp or pre-amp, a pure DAC, a DAC/amp combo, a USB->S/PDIF converter/regenerator, has multiple gain settings on the amp, multiple filter options on the DAC, has “iEMatch” for use with super-sensitive/low-impedance IEMs, a ton of power, all of the interesting inputs and outputs, a big on-board battery, which can be used to charge other devices, a neat USB connection that makes it very easy to use with an iPhone and Apple CCK cable, and adds both “X-Bass+” (bass enchancement, not just “boost”) as well as “3D+” which is a decent cross feed implementation.
The DAC section supports PCM and DXD up to 768 kHz and DSD upto octo-rate (DSD512) and features femto-class low-phase-noise clocks. And with the latest firmware it can do MQA rendering (you need a player that’ll do the first unfold, such as the native TIDAL client, Audirvana+ or Roon).
The amp section can push 4 watts into 16 ohms, with less than 1 ohm of output impedance. And for using very sensitive IEMs the “iEMatch” feature can be engaged to eliminate hiss and provide better impedance matching for multi-BA driver units.
Sound:
Initial impressions, straight out of the box, and using it as a DAC/amp, were of a very “exciting” delivery, with a little treble splashiness. Over a couple of hundred hours use, the treble splashiness went away and the overall presentation calmed down a bit. To be fair, the treble thing was only evident if used as a DAC/amp; using either the DAC or the amp separately did not exhibit this at all.
Bass is rich, well textured, and deep with decent slam, and not at all shy - perhaps even very slightly emphasized (less noticeable if used just as a DAC). Treble had good air and a pretty smooth rendering once things had burned-in a bit. The mid-range is relatively lush and lucid, and while not tube-like, is a bit more romantic in it’s presentation than I would consider to be “strictly neutral” - though perhaps not so much so that I’d actually call it “romantic”. That works for me, but has to be classed as “editorializing”, which not everyone wants in their audio gear.
I found the unit to be very musically involving and, post-burn-in, non-fatiguing with my normal audition playlist. Female vocals, in particular (and one of my favorite genres) were quite a treat here, with excellent tone, no sibilance, and more than enough resolution and micro-dynamic subtlety to appreciate the emotion in voices.
Macro dynamics are a strong point on this unit, possibly due to it’s high-power capability, but the micro-dynamics aren’t far behind. Tracks with major, fast-and-big-transient, elements can be quite startling (intro to “Under African Skies”, Paul Simon, Graceland).
Detail/resolution are both very good, making it easy to discern changes in bowing technique/position on violin solos. Separation and layering are not quite as impressive as some other units in this price-class, but they’re not bad and are really the only “weak” spot the thing exhibits.
Overall tone and timbre are convincing and natural, excepting that slight “romantic” element I noted. I didn’t find this to intrude on the music and actually rather enjoyed it, but it can result in a bit more mid-range attention (rather than emphasis).
And the amplifier section is very quiet. One of the quietest portable units I’ve ever listened to. Engaging iEMatch (which will work with any headphone, not just IEMs) results in the unit being absolutely silent even with things like the Shure SE846, EE Zeus XRA or Campfire Andromeda.
The sound is not the very last word in terms of nuance of subtlety, but it is engaging, entirely coherent and extremely enjoyable, with no notable issues or concerns.
X-Bass+ and 3D+
For me, where this is not a particular bass-shy unit at the best of times, engaging X-Bass was generally “a bit too much of a good thing”. With bassier cans/IEMS (TH-X00 Purpleheart, SE846) it was, however, a bit obnoxious.
This is an on/off thing, so there’s no real level of adjustment available. Very nice to have in the event that you’re transducers are a bit on the bass-shy side, but it probably goes a bit too far in compensating for anything else.
The 3D+ feature is a cross-feed implementation. It’s not as convincing as the one on the Pro iCAN. It fixes the 3-blob issue, but doesn’t do anything, for me, to improve the apparent “stage”. The most notable effect is that the treble gets boosted noticeably. While it works to help with some hard-panned recordings, it was something I preferred to leave switched off.
Headphone Pairing:
This is definitely one of the Micro iDSD BL’s strengths. You can pretty much pair it with anything. From the most sensitive IEMs, to cans like the LCD-4, Abyss and even the HE-6, it’s quiet yet powerful enough to drive all of them very well. Not the last word in refinement, but you won’t be under-juicing your cans.
It was very enjoyable with the Focal Utopia, HD650, HD800S, Fostex TH-X00, SE846, EE Zeus XRA, LCD-4 and the Abyss, which covers a pretty wide gamut of pairings.
In particular, I found the Micro iDSD BL + Fostex TH-X00 a rather “guilty pleasure” in that it was exceedingly entertaining to listen to, with a very punchy and exciting delivery. That’d get to be a bit “too much” after a couple of hours … but they’re a VERY fun two hours!
Value:
Very high - especially if you’re going to use it as an all-in-one and make use of some of it’s more interesting features. It’s particularly good value as a transportable unit that can drive all your cans and had a fully competent built-in DAC and AMP.
The inclusion of USB filtering/clean-up makes it a lot easier to employ well in a broad variety of systems, and the analog inputs and pre-amp capabilities make it very useful on the desktop as well.
Summary:
The package is more than the sum of it’s part. It’s good value, with excellent performance in all modes, and very easy to recommend - especially as an all-in-one solution. It’s flexible enough to grow with other aspects of a system (i.e. using it as a pure-DAC with a different amp, or as an amp with a different DAC).
Well worth auditioning if you’re in this particular market/budget segment.