Less is More | iFi iDSD Diablo-X Review

Less is More | iFi iDSD Diablo-X Review

When I think of some of iFi’s most recent and most popular products, I tend to be amazed at how the company from Southport, UK is able to consistently offer feature rich products with excellent sound at a justifiable price. While the prices on their flagship products, such as the iCan Phantom and Pro IDSD Signature may raise eyebrows, products like the Gryphon, GO pod, and the entirety of the Zen series offer incredible value at their respective price points. However, we’ve hit a bit of a crossroads with the Diablo-X, coming in at a flagship - for a portable DAC - price of $1099 without offering hit features found in more budget friendly models like XBass, XSpace, or even Bluetooth. While the statement “less is more” has been echoed throughout the years, does it remain true for the iFi iDSD Diablo-X?

Build and Design

With a rather less eye-catching design than that of the original Diablo, Diablo-X prefers to do its evil bidding in the shadows, wearing an all black exterior with tasteful accents of wine red on the volume knob, and all the writing on the unit itself. Diablo-X both looks and feels good, the chassis is sturdy and smooth, and with four rubber feet at the bottom, Diablo-X won’t go sliding off your desk so easily.

iFi Diablo-X highlighting front buttons and connections on top of AVM amplifier from Bloom Audio Gallery

Although theoretically portable, this DAC/AMP is going to fit most comfortably on your desk rather than your pocket. Coming in at 6.5" x 2.8" x 1.0", the Diablo-X will most likely need to reside in your bag for any listening on the go. In the front, you have your volume knob - that serves as a power button as well - in addition to a 6.3mm and 4.4mm input, and a switch with normal power mode, turbo power mode, and a MEMS setting - which we will dive into a bit later. On the back, you have a SPDIF input, balanced 4.4mm output, USB-C for power – with a small hole for an LED color to pop through to indicate charge level – and USB-A for input.

iFi Diablo-X highlighting rear face on top of floating shelf with Meze 99 Classics headphones

For accessories, iFi packed plenty of goodies to go around. Included in the box are 4 USB cables, iTraveler case, 5v iPower adapter, iEMatch 4.4, 4.4mm to Twin cable, a TosLink adapter, and a splitter male cable. Overall, iFi gives you everything you need here and more. Build and design out of the way, how will Diablo-X’s sound pair with an impressive build and finish?


Diablo-X follows in the footsteps of the original Diablo, and is as its predecessor internally. While this may come as a surprise to some, for those who have heard the original Diablo, they should know why iFi stuck to the philosophy of “if it ain’t broke, don’t fix it." Sticking to a more reference/analytical tuning, iFi Diablo-X does not stray from its roots.

iFi Diablo-X on top of wooden stool with HiFiMAN Susvara headphones from Bloom Audio Gallery

iFi Diablo-X boasts enormous power, and doesn’t flinch at the idea of powering even the most power hungry headphones. I quickly realized this as I went up the ladder of what we had available to listen here at Bloom. The age old question of “can it drive a Susvara?” was quickly answered when normal power mode and a 6.3mm unbalanced connection was enough for the Susvara to be driven at comfortable listening volumes. Turbo mode took things up a notch, making the Susvara really sing.

iFi Diablo-X on top of a leather couch accompanied by ThieAudio's Monarch MKIII from Bloom Audio Gallery

When not powering demanding planar magnetic headphones, Diablo-X can be used to deliver excellent performance amongst a multitude of IEMs. Using the iEMatch 4.4 adapter included is recommended for highly sensitive IEMs due to the power output of Diablo-X, but for the most part, IEMs and headphones alike have a black background that lets their strongest characteristics shine through. While there's really nothing here in the sound department to separate it from the original Diablo, there is a big difference between the Diablo-X (and a lot of other DAC/amps) which is the support for MEMs technology.


If you’ve been on Head-Fi in the past few months, or perhaps even got to listen to a demo at CanJam, you may be familiar with MEMS technology. If you’re in the large majority that's never even heard of it, you’re certainly not alone. MEMS technology has actually been around as early as 2007, and it uses decades old solid state technology for a large part of its process. However, what's being done with MEMS drivers in IEMs is relatively new, and Diablo-X becomes amongst the first of its kind to offer MEMS support. Without getting overly technical, MEMS drivers look to produce accuracy in music like never before, as MEMS drivers receive an electrical signal, vibrating the silicone membrane, thus making manually assembled voice coil approaches a thing of the past.

While this also sounds good in theory, how does it sound in practice? We were lucky enough to have Soranik - an industry leading company from Vietnam in the field of MEMS technology - send us an IEM to review. MEMS 2 is the world's first dual MEMS IEM and looks to take precision and accuracy to a new level. At $1200, MEMS 2 fits in your ear comfortably despite the nozzle being quite long. It’s quite a small and compact package, and reminds me quite a lot of Noble's Stage 3 in terms of fit and size. Featuring a black and red pattern, MEMS 2 and Diablo-X look like they were made for each other.

MEMS-2 IEM on top of the iFi Diablo-X accompanied by its included cable and aluminum case from the Bloom Audio Gallery

Upon listening, I don’t think I first appreciated MEMS 2's sound signature the way I’ve grown to now. At first, the bass appeared very thin, with not much impact at all. I changed my outlook on things the deeper I got into my listening, and while impact isn’t MEMS 2’s strongest characteristic, it does have a well extended low end that has a very fast nature to it. Again, not an IEM centered around giving you the most boom or thump, but definitely enough to satisfy that need for bass while still giving you enough detail and extension to appreciate it.

Mid range is well bodied, but I found the upper mid range frequencies to be a bit recessed for my taste, with vocals not being as present or full as I would like. Treble is where I believe the biggest difference is found, where a violin and clarinet can oftentimes go into excruciating detail, and at other times find themselves to feel a touch artificial. It’s a weird balance of both excellence and exaggeration, but as someone who enjoys sharp and tight treble, I found myself more times than not listening to classical and greatly enjoying a symphony of strings that pushes the limits of MEMS 2 treble extension.

MEMS-2 IEM on top of a Soranik aluminum case resting on top of a wooden stool from the Bloom Audio Gallery

To my ears, by far and away the best characteristic of MEMS 2 is the imaging and staging. Not only is it wide, it delivers excellent separation of instruments and deciphers the different layers of the mix incredibly well. Nothing feels out of place, and this is performance I would come to expect in the $2500 range and up for IEMs, let alone at $1200.

So where do we go from here for MEMS technology? Is it truly as advertised, and set to light the audiophile world on fire right out the gates? Considering as of now, this combo will run you $2299 for the price of admission to the world of MEMS, I’d say it’s going to be awhile until we truly find these to be common amongst most audiophiles. While the tech is certainly impressive, and MEMS 2 performs a bit above their listed price, I don’t believe there's much of a rush to get into MEMS now, as we have plenty of time to see how this technology develops.

When looking back at all of this, you might think that Diablo-X hasn’t expanded much on the original Diablo. However, it took an already polished design, with excellent sound, and became the first portable DAC/amp to offer MEMS support. Put Diablo’s power and versatility together with forward thinking MEMS technology, and Diablo-X makes a compelling case to be the next addition in your portable lineup.