First Listen: iFi Micro iDSD portable headphone amp/DAC/preamp

Just when you think those crazy kids over at iFi Audio couldn’t possibly fit any more headphone amp/DAC functionality into small packages, they turn around and do just that. What occasions this observation is the recent release of the firm’s brand new iFi Micro iDSD headphone amp/DAC/preamp ($499 US, £435 UK), which is without a doubt one of today’s most versatile, capable, full-featured, and powerful products of its kind at any size or price. To appreciate why I’ve made such a strong statement, read on.

Before we go much further, let’s make sure we’re clear on one key point: iFi’s Micro iDSD is a completely different product from the iFi Nano iDSD recently reviewed in Hi-Fi+. If this helps, it is useful to know that thus far iFi devices have come in two sizes: Nanos and Micros. Nano units are, roughly speaking, about the size of a large-ish deck of playing cards, while Micros are more nearly the size of two large-ish decks of playing cards, parked nose-to-tail. Fair enough?

Observation 1: There is nothing ‘micro’ about the Micro iDSD

The Micro iDSD combines two very desirable product concepts in one neat package; namely, the concept of a hyper versatile and therefore semi future-proof DAC plus the concept of a tiny yet exceedingly powerful headphone amplifier. Oh, and did we mention that the Micro iDSD can be configured (with fixed outputs) for use as a DAC connected to a conventional full-size hi-fi system, or configured (with variable outputs) for use as a DAC/preamplifier capable of directly driving either power amplifiers or active loudspeakers?

Yep, it does all that and more. Exactly what kinds of “more” are we talking about here? Well, one very cool touch is that the Micro iDSD can be, at the user’s option, powered either by its onboard 4800maH battery or directly powered (and/or recharged) from a USB port. Moreover, the Micro iDSD provides a SmartPower power port through which it can recharge smartphones and the like.

Observation 2: The Micro iDSD DAC is so versatile that it supports digital audio formats you may never have heard of before

The Micro iDSD DAC is based on a powerful, dual-core (that is, 2-chip) BurrBrown native DSD/PCM chipset and the things this device makes possible are pretty amazing. First off, the Micro iDSD is the very DAC I have ever encountered that can provide native support not only for standard and double-speed DSD (that is, DSD64 and DSD128), but also—get this—both quad-speed and octa-speed DSD (yes, that means DSD256 and, gulp, DSD512). Have I ever encountered an octa-speed DSD file? Not so far, but it’s fascinating to think that the Micro iDSD stands ready and waiting when or if the time comes.

Similarly, the Micro iDSD is also the first DAC I have run across that offers native support for both standard and double-speed DXD files (that would be, respectively, 384/32 or 768/32-bit files), plus native support for PCM files with sampling rates up to 768kHz.

Importantly, though, the Micro iDSD is more than just an exercise in extreme specsmanship (though it certainly is that), but also takes the trouble to offer essential, sound quality-minded touches such as a “GMT computer controlled Femtoclock” whose claimed jitter is less than 280 femtoseconds, plus a battery of useful filters with groups of settings optimised, respectively, for use with PCM, DSD, or DXD files.

Observation 3: The Micro iDSD’s amplifier section offers BIG power plus great flexibility

In one sense, the Micro iDSD could be viewed as incorporating five different amplifiers in on chassis. I say this because the amplifier provides three master power level mode settings (Eco, Normal, and Turbo), plus three iEMatch sub-settings that can be applied to the relatively low-powered Eco mode (this allows the amp to be fine-tuned for use with normal, high, or ultra-high sensitivity IEMs and headphones).

In Eco mode, the amp puts out maximum continuous power of 250mW @ 16 Ohms, with a maximum voltage swing of 2.0V, and with shorter term peak output of 500mW @ 8 Ohms. 

In Normal mode, the amp puts out maximum continuous power of 950mW @ 32 Ohms, with a maximum voltage swing of 5.5V, and with shorter term peak output of 1900mW @ 16 Ohms.

In Turbo mode, the amp puts out maximum continuous power of 1,560mW @ 64 Ohms, with a maximum voltage swing of 10.0V, and with shorter term peak output of 4,000mW @32 Ohms.

Quite frankly, these are output levels that a good many full-size desktop headphone amplifiers would find difficult to match, so they are well and truly impressive for what is, after all, a compact portable device.

Does this one-size fits all approach actually work under real-world conditions? Surprisingly, it does (I say ‘surprisingly’ because many have tried at this and many have, well, fallen short). Throwing all caution to the winds, I decided to try the Micro iDSD with two transducers that I think pretty much represent the Alpha and Omega of earphone/headphone sensitivity: the Noble Kaiser 10 CIEM (waaaay sensitive) and the Abyss AB-1266 planar magnetic headphone (low sensitivity and very difficult to drive).

With the appropriate setting in place (that would be, um, Turbo mode), the Micro iDSD grabbed hold of my reference Abyss AB-1266s and just plain made them sing, and with gusto. The sound was so full-bodied and confident that I almost found it hard to believe that it was coming from a portable amp/DAC.

Then, with the amps settings changed (to Eco mode with either the High Sensitivity or Ultra Sensitivity iEMatch switches engaged, the Micro iDSD shifted gears (downshifted, if you will) to become a fine and very quiet companion for the Noble K10 CIEMs (many amps, you see, tend to overdrive the K10s, but with the proper settings the Micro iDSD the match was an excellent one).

Honestly, the only other portable amp/DAC I know of that can compete with the Micro iDSD in terms of compatibility with a very wide range of transducers is the dramatically more costly Chord Hugo (though one might argue, of course, that the overall sonic presentation of the Hugo is more sophisticated and refined—as well it should be given the huge price differential involved). But at its $499 price, I think the Micro iDSD may prove well-nigh unbeatable (time will tell).

Observation 4: The iFi Micro iDSD retains the classic, eminently musical, iFi ‘house sound’

When you get right down to it, one of the reasons people either choose to buy (or not buy) iFi products involves the firm’s ‘house sound’, which is quite natural-sounding with generous helpings of organic warmth and an also generous helping of punchy-sounding dynamics. For many, this sound comes pretty close to a working definition of the term ‘musicality’, though for other a slightly leaner, more stringently neutral (and even a little bit analytical) sound might be more to their tastes.

If you love what iFi (and its bigger brother, AMR) have done in the past, there’s a very good chance you will enjoy the Micro iDSD as well.

I’m going to limit further comments on the Micro iDSD for now, partly to gain more listening experience with it, but partly so as not to spoil the formal review we will be preparing for Hi-Fi+ in the future. Watch for it in the months to come and until then, listen well.