iFi audio iDSD Diablo 2

iFi Diablo 2 ($1299)- The devil is in the details?

Diablo 2



Intro: iFi is an innovator. Presenting items that push the boundaries of what we need, the company clearly feels this path is working. I personally own the iDSD Pro and iCAN Pro for my reference desktop setup and still lament selling my OG micro iDSD Black Label. That thing was a beast. An untamed beast, which set the tone for transportable headphone amplifiers in the company stable. The OG Diablo was indeed an upgrade, taming the raw unfettered power of the original, without losing its character.

The Diablo 2 may not feel like a necessary item, especially to those who have ponied up for the first gen. But typical of iFi’s logic, there is enough new inside the Diablo 2 to warrant a look for those who may, while also drawing new customers into the fray.

I thank iFi and Lawrance for the loan of this device. After listening to it for approximately 75 hours, I have come to appreciate the lineage of its grandfather shining through on the grandson. Since it is a loaned unit, once it leaves I shall be reminiscing over my Pro Duo as a coping mechanism.

Caveat, since I am now part of the Headfonics team, my format has changed (for the better), but will add flavor like my blog reviews of old and some formatting from bygone days. Some things never change, nor should they...

Necessary items:

Gear Used/Tested:

FiiO GT3 (350 ohm)

Empire Ears Legend X

Spirit Torino Twin Pulse Beryllium IEM


Earmen Angel ($799)

OG xDSD ($399, priceless)

FiiO K9 Pro ESS ($799)

Centrance HiFi M8 V2 ($749)


Music:

Tidal-Jazz, Eilen Jewell, The Mavericks

Qobuz-Bill Evans, Sam Burckhardt & Lucas Montagnier

Etc

In The Box:

• Diablo 2
• USB-C cable
• USB-C-to-A adapter
• TOSLINK optical adapter
• 3.5mm to 6.3mm headphone adapter
• iTraveller carrying case
• User’s manual
• Inferno wings x4
• 5V iPower 2 charging wal wart

Specs (pulled from Headfonics review of Diablo 2):

• Qualcomm QCC518x 5.4 Bluetooth
• Dual Core Burr Brown chipset

• HI-RES support: 768k, DSD512, full MQA
• Bluetooth formats: aptX lossless, aptX adaptive, aptX, LDAC, LHDC/HWA, AAC, SBC
• Max output power 4.4mm: 19.2V / 611mW @600Ω or 12.87V / 5189mW @ 32Ω
• Max output power 3.5mm: 9.6V / 153mW @600Ω or 8.85V / 2450mW @ 32Ω
• RMS output power 4.4mm: 19.2V / 611mW @600Ω or 7.4V / 1710mW @32Ω or 11.5V / 2060mW @64Ω
• RMS output power 6.35mm: 9.6V / 150mW @600Ω or 8.1V / 2050mW @32Ω or 9.3V / 1360mW @64Ω
• xMEMS: 28Vpp (4.4mm output)
• Line out impedance: ≤ 200Ω
• SNR: ≥114db (A)
• DNR: ≥114db (A)
• THD+N: 0.002% @0DBFS 200kΩ
• Power consumption: Nitro 12W, Turbo 5W, Normal 2W, xMEMS 8W
• Battery: Lithium Polymer 4800mAh-up to 9 hours, and 5 hours to fully charge
• Dimensions: 166 x 85 x 28.5 mm
• Net weight: 455g (1lb)
• Digital inputs: 1x USB-C, 1x S/PDIF (optical/coax), Bluetooth 5.4
• Headphone outputs: 1x balanced 4.4mm / 1x 6.35mm
• Charging port: 1x USB-C

Unboxing:

As is typical with iFi, the unboxing is an experience to be had. Sliding off the glossy sleeve, you are met with the iFi logo-laden white box. Lifting the lid off, you are presented with the Diablo 2 wrapped carefully in parchment; tucked into a soft foam cutout.

Lifting the D2 out, you are met with another iFi item, the smile on the cardboard protective cover. Lifting that, you get the case (with the four Inferno wings) on one side, and split equally the power wall wart in one box and all of the adapters/accessories in the other.

Efficient, protected, and inclusive. iFi trademarks.

Build/Design:​

Going a different route has always been part of iFi’s DNA. The D2 is no different. The D2 departs from the more traditional log roll of the previous iterations, going for a slotted rounder shape with angular curves reminiscent of the Zen series.

iFi Audio includes brackets called “wings of Inferno,” which slip into the body's slots (only some of them) acting as stands. This makes for easier access on your desktop when properly placed I go back to my original word for the Black Label: a transportable device. It is still large for portable use, though. Keeping it in your attaché or backpack would work.

The front and rear angled panels give the D2 a certain cutting-edge design to the unit.

The iFi carries the typical company craftsmanship as well, with everything perfectly aligned and functional, without loose jacks or knobs.

Controls:​

The D2’s button placement and connection positions haven’t changed from the OG. The volume knob and headphone jacks are on the front along with a mode switch for adjusting gain and the additional xMEMS switch. All other connections are on the rear panel. The volume knob also has a lockout switch, so you do not accidentally bump it. This is a new feature and those who have had experience with iFi amplifiers know exactly what that means...

The Bluetooth function is selected by pressing a button on the rear panel, which also acts to switch sources between the USB input and the Bluetooth input.

Both panels on the D2 are packed full but have efficient use of space making for easy access to all jacks and functionality buttons. The front carries both 6.35mm single end and 4.4mm bal jacks. To the right is the mode switch that allows the user-selected gain modes (typically x3: normal, turbo, & nitro) and the volume knob.

The volume knob functions smoothly and has a good grip. As is typical of many analog pots, there is an unbalance between channels on the low end. This is alleviated by using the IEMatch switch on the bottom of the D2. You can leave it off (and have a noticeable unbalance), switch to 4.4bal (with a mostly even balance), or 6.35se (same results as 4.4bal) for better (or no) results.

The back panel carries the business ends of connectivity. You’ll notice two ports back there, a 4.4mm balanced connection and a 3.5mm SE connection, which act as both in and out. Until another reviewer pointed this out, it was not widely known to users, since it is not listed in the user manual.

This means that you can use the D2 with two separate components and access the DAC separately. You can then use the amplifier stage separately as well.

Tech Highlights:

The 16-core XMOS processor is pulled from the OG along with iFi Audio’s custom OV series op-amps, and a customized Burr Brown DAC section, which adds the necessary warmth to the sound. The Diablo 2 doesn't include the analog processing modes, XSpace, and XBass II, and it doesn't support digital filters other than Bit Perfect.

Also typical of iFi is the use of parts from the likes of TDK, Panasonic (expensive parts!), and Texas Instruments. If you have never immersed yourself on the page of a product from iFi, I highly recommend it, for the knowledge gained goes well beyond simply showcasing what and whose instruments are used packed inside.

Something called PureWave (fully balanced dual-mono circuitry), negative feedback, and differential mono design also carry over. I will admit that I have not heard the OG Diablo, so some of this will be new to me in this regard. According to their website, “Diablo 2 features PureWave, Servoless DirectDrive, OptimaLoop, and Advanced Jitter Reduction Technology, delivering exceptionally pure, detailed, and emotionally touching sound, these technologies elevate the performance to unparalleled heights, even challenging desktop DAC/amps.”

The visual circuitry changes with the addition of large 220µf capacitors within the circuitry. Rearranging the internals allows for the changes to fit smoothly into the mostly recognizable shape.

Bluetooth 5.4 receiving is another change, as well as the inclusion of an xMEMS capability switch on the front panel. I currently do not have anything capable of xMEMS, so this function will not be discussed.

An addition that continues from some of iFi’s other products is the iEMatch (Headfonics review link) feature that fixes a slight channel imbalance, which is common in analog volume pots at very low levels such as this. It worked, mostly.

The iFi Audio iDSD Diablo 2 runs most digital formats including MQA hardware unfolding. It can handle ‘Bitperfect’ PCM and DSD at up to 768kHz and DSD512.

Qualcomm’s QCC518x BT5.4 receiver handles many codecs including LDAC, aptX (including lossless and Adaptive), SBC, and AAC from transmitting sources such as mobile phones.

Amplification:​

iFi keeps their specs closer to the vest than most, and for good reason. Measurements of power should only be a guide, not gospel. I have heard plenty of so-called “low-power” amplifiers that would kick much more expensive units’ arses to the curb in comparison.

The power output rating of 5 watts is a peak rating, which occurs for a split second. Some say that peak power can improve transients and not overall sound quality to mention one caveat.

Having the three gain settings is a nice way to tailor your results for individual headphones and IEMs. You can expect a minimum of 2 watts RMS at 32Ω on the single-ended and the same on the balanced 4.4mm tap at 64Ω which is more than enough to drive most headphones comfortably. Max on the 4.4 is 611mW at 600Ω and 1710mW at 32Ω.

New D2 v OG V1:

The Diablo 2 has an improved power supply and amplifier that increases balanced power output at 32Ω by 50%+. There is also 4 times more output in balanced power compared to the single-ended at 600Ω.

The new model also features a more accurate analog volume pot along with xMEMS, BT Lossless (on available play units, which aren’t many right now), and other options such as the input/output options on the back (USB-C and 4.4bal).

All of this comes at a price increase of $300, though.

Battery Life:​

Rated for 8 hours, you will most likely get 5-6 hours depending upon volume and gain settings from the 4800mAh Lithium-Polymer battery. An included 5-volt BC v1.2 compliant charger can handle a rate of 1.9mA which translates into a few hours to charge the battery. I did read somewhere that it can take up to five hours for a full charge.

You can leave it plugged in when using it at your desk, and there is even an auto-off function, unlike the OG.


Wireless Connectivity:

Bluetooth:

BT5.4 using Qualcomm’s new QCC518x Bluetooth audio chip can support all CODECS including aptX Lossless, aptX Adaptive, aptX, LDACTM, LHDC/HWA, AAC, and SBC.

The connection was straightforward, and the switch on the back allows for easy switching between BT and a wired source. While not quite on par with a wired connection, the sound coming forth was quite good, closing the gap even more.


Wired Connectivity:

USB-DAC:

Connections include a USB-C on the back as well as a 4.4mm balanced in/out connection. The same holds for the 3.5nn single-ended connection on the back. Having the ability to connect two sources simultaneously allows the user to define what they want as the source, twofold. This would be convenient if you dislike changing cable often, as I do.

Add in the USB-C connection, and you could theoretically have three hooked up. I did not try that, though.



Sound Impressions:

All listening impressions were made with the Empire Ears Legend X, Spirit Torino Twin Pulse IEM, FiiO GT3 (350 ohm), ZMF Eikon, and AKG 240DF.

Summary:

As the name implies, the Diablo 2 is not shy about its signature. Running on the brighter, or hotter end of the spectrum, there is (to me) also the traditional iFi warmth and richness in the sound signature as well. Detail retrieval comes across with aplomb, rather than succinctly, making for a vibrant, rich character instead of a detail-driven cacophony of musical notes.

The high gain is also evident, reflecting iFi’s character for driving things into overdrive. Anytime you see “turbo” and “nitro” on the gain settings, it is not for the faint; nor to be made fun of. Through all of this, the clarity comes across as purposeful, instead of staccato-like. You engage within the music, instead of listening to it.

Timbre:

There is no getting away from the name and the sheer power the D2 can deliver. But as stated above, it is purposeful with detail to back the goods up. Richness pervades the tonality, and bass, which can reach low carries good weight without becoming intrusive or overdriven.

As the lows go, so do the highs. Spread evenly, you could be forgiven for thinking the response is near-neutral. Instead, there is an organic, heft to the note caliber, which gives you a naturalness that compliments the even tonality. I keep going back to my iFi Pro Duo for the signature equivalent but with a bit better detail retrieval. Mind you, the Pro duo has that luxurious tube sound, to compliment all involved.

The sparkle up top compliments the grunt down low, without overwhelming the middle range and that organic nature of it.

Staging & Dynamics:

With the excellent transient response, you are kept firmly aware across the FR curve, and there is a good weight to the notes, too. The speed and decay are shortened on most notes, making for a quick attack of sound, but without becoming thin or analytical. The vibrancy of the presentation allows the listener to gauge accurately where all of the instruments are playing and what plane they reside in.

All of this leads to an accuracy of sound, which steps away from the iFi Pro Duo, which is more about the overall presentation. Seemingly, the better the headphones or IEM, the better the response was, and I found myself moving upscale in my collection to see just how far the D2 could persuade pleasing music from.

The soundstage was lifted, but not overly; making for an uplifting presentation, which stretched the height. The width was excellent, and the depth was almost as good. This was not a cubic presentation, but rather a spacious one, which allowed the notes to breathe within the realm of the stage.

I never had a problem with power, either so I am one to give iFi a pass on any of those “transgressions,” with which others speak. Having the ability to run three gain levels allows the listener to use many within their spectrum of listening devices with great pleasure.



Comparisons:

iFi Diablo 2 ($1299) v iFi iDSD/iCAN Pro duo ($2999ish):

Long held as my “reference set,” the duo carries functionality that would still make many others blush. BT, WiFi, tube sound (and adjustability), along with 3D holography adjusting, and a multitude of filters. The ability to change on the fly makes this still one of my all-time favorite setups.

Truthfully, this isn’t really a fair competition when one looks at the price, but when you factor in age it becomes a bit clearer. The D2 is the “latest and greatest” from iFi, while the pair is their gold standard, even if it may be considered the grandfather of the company. And, as we know, if you come for the king, you best not miss.

The D2 while a brash youngster, takes lessons from the elder in showing off a mature presentation, but with an edge. Where the pair goes for an overall fluidity (and tubey goodness), the D2 goes for cutting-edge details with a vibrant character, that still exudes the familial organic sound (a bit).

You can drive both into oblivion, but both still hold their mettle when called upon to do so. Where the D2 dances a quicker-paced, response-oriented signature; the pair exude a maturity that the D2 cannot match. That is if you prefer that signature. As such, the two family members would complement each other very well whether on your desktop or save the D2 for “transportability.”


iFi Diablo 2 ($1299) v EarMen Angel ($799):

EarMen is known for making superb-sounding devices, which put much more expensive gear to shame. Having Auris as a parental company pays off, with trickledown tech, that can make others blush in jealousy. Except if your name happens to be iFi.

The EarMen does not boast the connectivity options of the D2, nor does it do BT, either. It simply connects and plays. And plays well. While not quite as much of a looker as the D2, it is under the skin where the magic lies.

Boasting almost as much power as the D2, you can run your ears to bleeding with the Angel, begging for mercy just as much as the D2. Where the D2 sounds rich, the Angel sounds vibrant. Where the D2 sounds accurate but smooth; the Angel sounds vibrant and detailed.

The Angel does SP/DIF connectivity as well as the D2, for those who may want to utilize either into another amplifier or two-channel system through this connection.

This will come down to whether you want a bit more vibrant, detailed signature (that may sound a bit thin to some) in the Angel, or the versatility and multiple gain settings of the D2 along with as much power.

Me? I’d like both, please.


iFi Diablo 2 ($1299) v iFi xDSD ($399):

There is no denying the familial heritage of the xDSD (and xCAN for that matter). I personally prefer the xDSD since it is a dedicated headphone amplifier. For sheer power, the xDSD is hard to beat in a size v punch comparison. Vibrant in character, but not as much so as the Angel; the xDSD shows off in power and accuracy instead of a mature sound.

With 3D+ and XBass, you can also add grunt down low along with some holography to the sound. But, when it comes to comparison, the D2 dwarfs the older cousin in sheer power and the ability to come across with the richness in signature that may be missing.


iFi Diablo 2 ($1299) v Centrance HiFi M8 V2 ($799):

The pairing of the M8 V2 and the Ampersand almost made me clean out my whole collection of desktop units, and replace all of them with the pair. Almost. Knowing that you could just as easily take the pair with you on the go made them all the more appealing. And that is kind of the point since Centrance started with on-stage gear for musicians.

That precision for musicians’ choice shows through in as detailed a signature as you will find in a portable/desktop setup at the price and beyond. I chose the M8 V2 as a comparison here due to the connectivity options; including BT, and it can hold its own against the D2 with everything, except sheer power.

Where the D2 goes for richness and power, the M8 V2 goes for accuracy and detail, but without thinning the notes. I have yet to find pretty much anything at the price, that can provide a sound as accurate as the Centrance, save maybe the Angel; but with a slight thinning of notes.

The D2 can compete against the more affordable M8 V2 due to connectivity options, and the gain settings, with a bit more power.



finale:

Having not heard the OG Diablo, but enough other iFi products over the years, I do feel that I can make a reasonable judgment as to the D2. If you don’t have a Diablo or iDSD micro–Black Label (I still miss mine...), the Diablo 2 is a powerful DAC/Amp with a hotter sound, decent battery life, and a bet against obsolescence in the future due to the inclusion of Lossless Audio, xMEMS, and the latest BT. You also get plenty of connectivity options, and enough power to run a small city.

But if you already have the Diablo? You may want to wait or purchase one of the iFi dedicated desktop units. Of course, having options is a good thing; and you could get both. Your call.

The iFi iDSD Diablo 2 is the successor of the original iFi iDSD Diablo which was one of the most powerful, battery powered portable DAC/amps in the market. This updated version of the product adds several new features as we are going to find out later on.

Technical highlights

The Diablo 2 is a battery powered DAC/amp that can be used at home and mobile. The DAC chip used is a Burr-Brown True Native chipset that offers ‘bit-perfect’ decoding. An XMOS 16-Core chip processes the audio data received via the USB and S/PDIF digital inputs while a GMT (Global Master Timing) femto-precision clock and intelligent memory buffer are used for jitter eradication. The Diablo 2 supports PCM 768kHz, DSD512 and full MQA decoding.

Unlike other iFi DACs, like the NEO iDSD 2, the Diablo 2 doesn't include the analogue processing modes, XSpace and XBass II, and it doesn't support digital filters other than the bit perfect.

A fully balanced dual-mono circuitry, called PureWave, elevates clarity by separating channels and reducing noise while DirectDrive removes the need for coupling capacitors and OptimaLoop employs tailored multiple feedback paths in the amplifiers, refining gain control and reducing distortion.

The Diablo 2 supports xMEMS solid-state micro-speaker technology, enhancing performance of compatible IEMs and headphones.

Contrary to the original Diablo, the iFi Diablo 2 features wireless Bluetooth 5.4 reception with support of the new aptX Lossless codec for lossless CD-quality streaming. This codec is not yet that widespread but you shouldn't be worried as the Diablo 2 is also compatible with the aptX Adaptive, aptX, LDAC, LHDC/HWA, AAC and SBC codecs. Bluetooth reception is strong and stable while sound quality is exceptionally good with some degradation, most notably in the treble.

Extra features vs the iFi Diablo 1

When compared to the original iFi Diablo, the Diablo 2 has improved power supply and amplifier designs that translate in a 52% increase in balanced power output at 32Ω and 405% increase in balanced power output compared to the SE output at 600Ω. Additionally the new model features a Quietline control system, iEMatch for 3.5mm and 4.4mm, Bluetooth (Lossless) input, support for xMEMS, MQA over SPDIF, USB Type-C input, a volume locking mechanism and enhanced analogue volume control with improved accuracy (+/-0.6dB vs. 1.5dB before). The downsides are that the iFi Diablo 2 is bigger, heavier and $300 more expensive than the original.

Non Audio stuff

The iFi Diablo 2 has grown bigger and heavier (166x85x28.5mm/455g) than the already big Diablo so it is not exactly portable but rather transportable. This is not a device that can fit in your pocket, you are going to need a small carrying bag for moving around with it. Thankfully a high quality carrying case is included in the package.

The minimalistic and industrial design resembles that of its predecessor but now it has twenty-two curved rails for improved cooling performance. Eight of these rails are compatible with four wind shaped stands that are included in the package and can be used to position the device vertically or horizontally to save space. The red/gray aluminum chassis is very well made and looks extremely sturdy, the only thing of note is that the back side has corners and edges that are a little sharp. Those engraved channels might work well, because the Diablo 2 runs very cool, but they attract dirt and are difficult to clean.

The generously accessorized package includes long USB type-C to C, short USB type-C and lighting cables together with a USB type-A adapter. Another cable converts the barrel jack of the included iPower 2 power supply to a USB type-C jack. There are also included 3.5mm to optical and 6.35mm jack adapters and an iFi travel case with a shoulder strap.

At the front face of the Diablo 2 you can see two headphone outputs (6.35mm and 4.4mm), xMEMS and gain switches, a volume control knob, with a newly added lock mechanism that prevents accidental adjustments, and a LED that displays the input sampling rate.

At the back panel there are two USB type-C ports, one for data input and one for charging, a S/PDIF 3.5mm input, a 4.4mm line input/output, a battery status LED and the input selection button. Positioning the battery status LED at the back was not a smart idea as it is not practical at all.

Pressing the input button once will place the Diablo 2 into Bluetooth pairing mode. The other digital inputs are automatically detected, the USB has priority over S/PDIF and both over line input. The line input is 3.5mm only and in order to work you must have all digital inputs unplugged and Bluetooth switched off. Otherwise this jack will work as a line output.

Battery and DC mode

The power source of the iFi Diablo 2 is a 4800mAh battery that gets charged by a dedicated USB type-C port so it is possible to charge and do USB decoding at the same time. The battery needs about 5 hours for a full charge and its duration ranges from 8-9 hours at the best, to 5 hours depending on the load, the gain setting and whether the Bluetooth is enabled or not. The unit sports an auto power off feature that shuts it down after about half an hour or inactivity.

An additional feature of the iFi Diablo 2 is that it can be powered by mains. The bundled 5V iPower 2 power supply features Active Noise Cancellation II, effectively canceling out all incoming EMI and RFI noise. Unlike the FiiO Q7 there is no switch to manually enable the DC desktop mode and bypass the internal battery. The procedure is automatic, and there is no way of physically switching it. The way it works is that once plugged in and the battery gets fully charged, it switches internally to the mains power and only supplies battery power when it falls below a certain level.



Audio stuff

The Diablo 1 was already a very powerful portable DAC/amp but its low gain setting was too aggressive for use with sensitive earphones. The iFi Diablo 2 is even more powerful than its predecessor and additionally it fixes this issue by incorporating a third gain setting and iFi’s iEMatch technology. This feature is tailored for high-sensitivity headphones and earphones as it removes background noise and increases the usable volume range. The feature is enabled by a switch located underneath and is separately available for the 6.35mm and 4.4mm headphone jacks.

The Diablo 2 offers three power modes: Normal for IEMs, Turbo for mid-sensitivity headphones, and Nitro for demanding headphones, boasting a 19.2V maximum output. The maximum RMS power output of the 4.4mm jack is 19.2V/611mW (600Ω), 7.4V/1710mW (32Ω) and 11.5V/2060mW (64Ω). Furthermore the Diablo 2 has a unique design that allows it to offer a max peak power of ~5.2W(32Ω) per channel thus allowing exceptional headroom.

To get a rough idea about the actual performance of the Diablo 2, the Focal Clear Mg gets pretty loud halfway the volume range (normal gain/4.4mn) and the same applies to the sensitive FiiO FX15 but this time with the iEMatch enabled. The Diablo 2 has absolutely no problem driving headphones like the Sennheiser HD660S2 while it is one of the few portable, battery powered amps that can sufficiently drive the HIFIMAN Susvara. The amplifier is also dead silent and noise free when used with very sensitive IEMs like the Soundz Avant.

The overall sound signature of the iFi Diablo 2 sits somewhere between the original Diablo and the iFi NEO iDSD 2. The Diablo 1 was surprisingly neutral and flat sounding for an iFi product (just like the NEO iDSD) while the NEO iDSD 2 has a warmer and more organic sound presentation, quite reminiscent of an analog set-up. The Diablo 2 is a bit warmer and more euphonic sounding than the Diablo 1 but not as much as the NEO iDSD 2. What we have here is a well thought balance between class-leading transparency and neutrality with an engaging and musical character that will make your music sound alive and lifelike with respect to the recording.

The Diablo 2 has a powerful and dynamic low-end, the bass is punchy, impactful and realistically contrasted. The texture is not as visceral as in the NEO iDSD 2 but is weightier and not as lean and dry as it was in the Diablo 1.

Slightly warm, speedy, tight and controlled with excellent definition and top-tier layering, the Diablo 2 will shake all your headphones and unleash deep bass while offering technicalities of the highest level.

The iFi Diablo 2 is still a little bit aggressive and vibrant but not as nervous and exposing as its predecessor. This time it is much easier to match with various headphones, even brighter ones, as the treble is relatively smoother and not as bright or sharp while the mid-range is linear and neutrally tuned without accentuation.

The sound is sparkling and energetic but the timbre manages to stay rather natural and realistic, the Diablo 2 has a hint of warmth and plenty of harmonic variety that were slightly missing from the original model. Voices and instruments sound lifelike as they have excellent tonal and timbral accuracy. The textures are full and weighty, the sound is devoid of any severe artificiality and is not sterile. Detail retrieval is excellent but Diablo 2 avoids the trap of sounding analytical and clinical.

The Diablo 2 poses sound fluidity and sonic richness while it offers top shelf resolution and refinement as someone would expect from a flagship product. The soundstage is both deep and expansive, given that you have an equally skilled headphone. There is plenty of ambient information on tap, the Diablo 2 is exceptionally skillful when it comes to imaging accuracy and will make your headphones sound grand and immersive.

Comparison with FiiO Q7

The $799 Q7 is FiiO's flagship portable (transportable) DAC/amp boasting similar features with the iFi Diablo 2. It uses a single ES9038PRO DAC chip in a fully balanced configuration with dual THX AAA 788+ amplifiers that can do 3WPC (32Ω) in desktop mode and 1.5WPC (32Ω) in battery mode.



The FiiO Q7 features a manually switched DC desktop mode that completely bypasses the internal battery. The downside is that you need a 12V power supply to do the job when the Diablo 2 can be DC powered by a 5V phone charger. The Q7 supports Bluetooth connectivity but without the aptX lossless codec, it has a couple of more digital inputs and analog outputs but it doesn't support line input. The Q7 also has a tiny OLED screen and is compatible with the FiiO control application that allows deeper customization. The Q7 measures 158.4x88.5x28.3mm and weighs 620g compared to the 166x85x28.5mm and 455g of the Diablo 2.

When it comes to sound, the most notable difference is that the FiiO Q7 is a bit more technical and transparent sounding than the Diablo 2 but also a little sharper and less organic. The Q7 is more dynamic and impactful than the Diablo 2 but it has drier and somewhat leaner textures while it is a tad less forgiving and more exposing. Resolution is on the same level for both and while the Q7 has marginally sharper imaging than the Diablo 2, the soundstage is not as holographic and immersive as in the Diablo 2.

Conclusion

Species keep evolving, constantly adapting to their surroundings to become better and stronger than their ancestors. The same happened with the Diablo that successfully evolved to the Diablo 2 which is more powerful with better sound quality and many new features than its predecessor. Not without a cost of course as it is also bigger and more expensive than the Diablo 1. The iFi Diablo 2 belongs to a new generation of products that are designed to be used as portable and desktop, all-in-one, audio devices at the same time. It is a flagship level product with features and audio performance that can justify the price of admission but the truth is that it would be more competitive and better value for money if price was a little lower.

The iFi Diablo 2 was provided as a loan and now is returned back.

The price of the Diablo 2 is $1299 and you can buy one from iFi shop.

A more comprehensive version of the review is available in my website.

DISCLAIMER

The Diablo 2 is a loaner from iFi. It will be returned after this review.
It can be gotten here (no affiliate links): https://ifi-audio.com/products/idsd-diablo-2/.




SPECIFICATIONS/COMPATIBILITY

The Diablo 2's engine is a dual DSD & DXD Burr Brown DAC chip, which is lauded for its buttery smooth house sound. It can function as a DAC, amp and Bluetooth device.

This DAC/AMP is compatible with multiple music formats. PCM can be played up to 32-bit/768 kHz, with native playback up to DSD512, with full MQA decoding. The Diablo 2 supports a myriad of Bluetooth codecs, which we will talk about below.


ACCESSORIES

Other than the Diablo 2, these are included:
- Carrying case with sling
- 3.5 mm to 6.35 mm adapter
- Optical adapter
- USB-C to USB-A adapter
- USB-C to lightning adapter
- USB-C to USB-C adapter x 2 (long and short)
- Power supply brick, with adapter
- iFi stickers x 2
- 2 sets of desktop wing stands




Verily, the accessory line-up for the Diablo 2 is befitting of a kilobuck source. Both Android and Apple ecosystem users should be covered. Everything that an audio enthusiast should require is inside, perhaps other than the lack of a 2.5 mm adapter, for users who are still using this cable type.




Well, a small nitpick would be the absence of a hard case, or at least a semi-rigid one. While the Diablo 2 is sturdy enough, the provided carrying case is soft and would not survive a drop or compression - and heaven forbid that the kilobuck Diablo 2 should suffer such a fate!

The Diablo 2 comes with four desktop wings stands that you can use to elevate the device. This can aid in accessing the iEMatch button located at the bottom, and also for cooling the device.


DESIGN/FUNCTION



The Diablo 2 is fashioned from metal, and comes in a provocative silver and red motif, with sleek vertical lines along the chassis. It is literally built like a tank, but is quite large, measuring 166 x 85 x 28.5 mm and weighing 455 g. Thus, the Diablo 2 is probably best suited to be a desktop source or for stationary usage, rather than being something pocketable.




On the front, we have an analogue volume knob and the single-ended (6.35 mm) and balanced (4.4 mm) outputs, which are reinforced with gold-plating. Rotating the volume knob clockwise will turn the device on.

Interestingly, iFi has included an innovative volume lock button on the 7 o' clock position of the knob, which can prevent the knob from inadvertently being excessively turned, thus protecting the user's precious ears and transducers! The volume knob is also very finely tuned, with minimal channel imbalance even at low volumes.

On this panel, we also have a vertical switch to toggle 3 gain settings, which iFi has creatively named "Normal", "Turbo" and "Nitro", in ascending gain levels. Additionally, there is an xMEMS tab to pair with xMEMS compatible transducers, but I do not have any of these gear to pair with the Diablo 2 unfortunately.





On the rear of the device, we have separate USB-C charging and data ports, in addition to an optical input. There is a Bluetooth button too, on the extreme left.



The Diablo 2 is equipped with an inbuilt memory function, it will recall the last mode (wired or Bluetooth) that the device was set to, when powering it on.

The Diablo 2 has no LED screen unfortunately. Surprisingly, it also has no XSpace/XBass buttons, unlike some other iFi products. Thus, for folks who want to boost bass, you might need to resort to EQing it on the upstream source.




On the base, we have the serial number and a built-in iEMatch, which is an extremely useful tool for fussy low impedance/high sensitivity IEMs, to mitigate for hiss and impedance mismatch. The iEMatch is actually quite different from other impedance adapters, in that it does not skew the frequency response of IEMs with a variable impedance curve. So fear not, some fastidious gear - such as the infamous Campfire Andromeda - can be readily paired with the Diablo 2.





BLUETOOTH

The Diablo 2 is the world’s first portable DAC/AMP with Bluetooth 5.4, via Qualcomm’s new QCC518x Bluetooth chip. Additionally it supports the pioneer aptX Lossless codec, which theoretically hits a maximum bitrate of 1,200kbps. In contrast, the previous 2 so-called high bitrate codecs of aptX Adaptive and LDAC can only reach a bitrate of 420kbps and 990kbps respectively.

The following are the Bluetooth codecs that this device supports:

• aptX Lossless
• aptX Adaptive
• aptX
• LDAC
• LHDC/HWA
• AAC
• SBC

During my field tests, the Diablo 2 was easily recognized by multiple Windows and Android devices, including DAPs. I apologize, but I do not use Apple devices, so I can't vouch for these.

Bluetooth connectivity and range with the Diablo 2 is only so so. Range-wise, we can hit around 10 meters without obstructions, and 5 meters with obstructions. Unfortunately, there was some stuttering and occasional drop outs with longer distances or larger obstructions.


BATTERY

The Diablo 2 can be powered by battery or mains. The battery can actually be bypassed with the 5V wall charger, which can help preserve battery charge cycles, especially for consumers who want to use the Diablo 2 as a desktop source only.

In theory, battery-fed sources should provide cleaner power, via mitigating "dirty" mains power problems like RFI and EMI, but on the flip-side, battery-driven gear may pump out low output voltage, or have variable output impedance as the batteries discharge. It is thus good that consumers have an option for both.

Packing a lithium-polymer 4800mAh battery, I can achieve between 6 - 12 hours battery life with the Diablo 2. Higher gain, louder volumes and lossless files definitely burn more battery, but on average, thru wired connection and FLAC/WAV files at moderate volumes, I can get at least 10 hours on a full charge. Do bear in mind though that with repeated charge cycles, battery life will be expected to drop.

One nitpick - the Diablo 2 takes very long to be charged. We need around 12 hours and 5 hours for a standard and high-powered charger, respectively, to fill up this beast.




SOUND

Like most Burr Brown-based sources, the Diablo 2 has a warm-neutral tuning. It isn't as analoguish as other iFi products, but is still a hair thicker in note weight than neutral. This device has dulcet smooth tones that makes it a great pairing with edgier or harsher transducers. Timbral accuracy is very organic and a joy to listen to.

End-to-end extension is solid, and the Diablo 2 has good technical chops, despite not being steroid boosted in the treble, unlike some other brighter sources with "fake resolution". An expansive soundstage and beautiful layering greets the listener. Bass is very punchy and controlled. The midrange is lush. Treble is relatively sibilant-free but not lacking in micro-details.

Not to flog a dying horse, but I'm sure some readers here are cognizant about the Diablo 2's power specs controversy regarding max power versus continuous real-life specs, but FWIW, this device is still a powerful behemoth even with RMS specs. These are the data provided by iFi:

On balanced:
>19.2V/611mW (@600Ω);
>7.4/1710mW (@32Ω);
>11.5/2060mW (@64Ω)

On single-ended:
>9.6V/150mW (@600Ω);
>8.1V/2050mW (@32Ω);
>9.3V/1360mW (@64Ω)

These are my usual acid tests when testing out a new source:
- Final Audio E5000 (low sensitivity at 93dB/mW)
- Sennheiser HD650 (high impedance at 300ohm)
- Yinman 600 ohm (600 ohm impedance and 87db/mW sensitivity)

I'm glad to report that all 3 tough customers were easily driven, with an abundance of headroom to spare. The first 2 (Final E500 and Senn HD650) were juiced well with excellent dynamics, with a tight and clean bass ensured. Many weaker sources would have furnished a flabby one-noted bass, with a boring soundscape.

The final boss - the Yinman 600 ohm (600 ohm impedance and 87db/mW sensitivity) - fails to be driven properly by the majority of portable sources. Happily, the Diablo 2 aces this assignment with aplomb. It is not a matter of volume, but control - the Yinman has a textured bass with a spacious soundscape with the Diablo 2, and they are a match made in heaven.

With the iEMatch, the Diablo 2 has <1.0 ohm output impedance both output ports, which is great for low impedance gear, based on the audiophile rule of eights. Hiss can also be easily fixed with this iEMatch.

The Diablo 2 does not get overly warm during prolonged usage, even with harder to drive stuff, which is much appreciated.




CONCLUSIONS

The Diablo 2 is a TOTL source, which can function as both a desktop and a portable device. It can be powered by both mains and battery, with a more than decent battery life. It is built like a tank, with a princely inclusion of accessories, in addition to multiple inputs and outputs. With no hiss, nor EMI, it also does not get hot with usage, which are all big pluses in my book.

Sound-wise, the Diablo 2 bestows a warm neutral agreeable tonality, with natural timbre and good technicalities. Think of musicality meeting technicalities, an amalgamation of relaxing to music, yet not losing too much resolution.

Power controversy aside, it packs enough power to still drive most gear out there. The addition of the iEMatch guarantees compatibility with fussy gear, so essentially, the Diablo 2 can drive high sensitivity IEMs all the way to full sized planar cans, with 3 gain options on the table.

There are also many interesting innovations on this device, such as an xMEMS compatible tab, being the world's first portable source that utilizes Bluetooth 5.4, and compatibility with the ultra-high bitrate aptX Lossless codec. Unfortunately, Bluetooth connectivity on this DAC/AMP is not the best in terms of implementation, with occasional stuttering and dropouts, especially when obstructions come into play.

I would be sad to return this loaner unit. No doubt the Diablo 2 is not 100% perfect, and there are diminishing returns once we reach kilobuck prices - costing north of $1200 USD, the Diablo 2 is indeed on the pricier side. However, as an overall package, the sonics are really quite addictive, and once you heard something nice it is quite hard to unhear it!

Hi Guys,

Today we are taking a look at a new product from iFi Audio, the iDSD Diablo 2. This is the most recent iteration in their Micro iDSD lineup, of which I am a long-term fan. The Micro iDSD lineup has always offered a great set of features and performance for their price point, making them a default recommendation for anyone looking for a great transportable headphone DAC/Amp combo unit. The new Diablo 2 has a couple of different features that are new for the Micro iDSD lineup, whilst it is lacking some of the features others have (similar to the original Diablo.)

The first thing I should talk about, which has been a point of contention on forums in recent times is the power rating for the Diablo 2. iFi has always advertised peak output power, versus continuous RMS. The Diablo 2 is advertised as having 5180mw of output very similar in amount to the previous Diablo 1. This is peak output so for very short peak transients it can manage this output, but for continuous power, it can only manage about 2000mw or just under (depending on the resistance.) This is similar to the Pro iCAN, which is advertised as having 14,000mw of output, but again this is peak output and probably managed somewhere about 8000mw in terms of continuous RMS power. In terms of real-world use, for a transportable device, this is totally acceptable and even impressive for a device of its size and general use case. I didn’t have any trouble with the output power of the Diablo 2, as it is very similar to the Diablo 1. One thing to take note of is that the lower the resistance of the headphones (ohms) that you are using, the more it makes sense to use the Diablo 2’s single-ended output, as it delivers more power from the single-ended output into lower resistances than from the balanced output. The extreme case that I ran into this was with the Audeze LCD-5 which has an incredibly low resistance value of 14ohms. I ran into the current protection engaging with the LCD-5 with bass-heavy music at medium volumes using the highest gain setting on the 4.4mm output. Using the 6.35mm output with the LCD-5, I had no issues. Other than that pair of headphones with their unusually low resistance, the Diablo was totally usable in terms of power output.




Now that we have got that disclaimer out of the way, let’s talk about the product in general. The Diablo 2 adopts a new ridged metal case with a nice red anodized finish. Similar to the previous Diablo 2, it has a 6.35mm single-ended output and a 44mm balanced output. There are three gain modes, which have been renamed from the older Micro iDSDs. I don’t like this decision, as the actual gain levels are the same, and it will just create confusion with past products. This means that the levels are 0dB, 9dB, and 18dB, but instead of being called Eco, Normal, and Turbo, they are called Normal, Turbo, and Nitro. Same thing, but it makes it sound like the new “Nitro” mode has a higher gain setting than the old Turbo mode, which it doesn’t. New name, same thing. Another thing which can add confusion for newer users is that iFi is using the term “NOS” (as in nitrous oxide – “Nitro”) to describe the highest gain setting. For someone who doesn’t do a lot of reading about the product, this brings up an issue as NOS in “audiophile speak” could mean “Non Oversampling” with regards to the DAC portion of the Diablo 2, or it could even mean “New Old Stock” with regards to vacuum tubes (which the Diablo 2 most certainly doesn’t have.) The old naming scheme for the gain levels wasn’t broken, it didn’t need to be fixed and seems almost dishonest in that iFi seem to be trying to get people to think the Diablo 2 has a new higher gain higher power output, which it doesn’t.

The Diablo 2 comes with a neat plastic stand which is handy if you are going to be using it as a desktop unit, tilting the front panel upwards to allow for easy access to the front panel. The Diablo 2 also still has iFi’s IEMatch feature, which is selectable on the bottom of the unit. Also new for the Diablo 2 are the USB-C inputs on the rear of the device. This means a USB-C input for data and a USB input for charging. I do wish the Diablo 2 had the feature the Gryphon has to combine charging and data on one input as an option. You are able to charge and also bypass the battery of the Diablo 2, and use a 5v iFi wall wart which comes stock with the Diablo 2. This is handy for anyone who is going to be primarily using the Diablo 2 as a desktop unit. Also on the rear are a SPDIF 3.5mm coax/optical combo input, and a 4.4mm input/output for use as a DAC only, or an amp only. Also on the rear of the unit is the Bluetooth pairing button, a new feature for the Diablo 2 in comparison to the Diablo 1.




The most noticeable new feature on the Diablo 2 is support for any new “X-MEMS” driver-equipped IEMs. X-MEMS is a new driver technology in the IEM space which requires a dedicated amplifier, and it is really only starting to be adopted by manufacturers as we speak. Whether or not it will be widely adopted in the future I don’t know, nor have I heard any example of an X-MEMs driver IEM thus far. However, the feature is present on the Diablo 2, so if you happen to be an early adopter of the X-MEMS tech, the Diablo 2 has you covered.

The sound of the Diablo 2 is incredibly similar to that of its predecessor the Diablo 1, which I reviewed in the past. I would recommend popping over to that review if you are interested in more comments about the Diablo 2’s sound quality in addition to this review, due to how similar they are overall. It is slightly leaner and brighter than the older Micro iDSD models. The bass is quick and precise, and I would say very neutral in its overall level. The mids are less warm and have less presence, especially in the low midrange compared to the older Micro iDSD models. The treble is slightly brighter but also slightly more detailed than the older Micro iDSD models. The Diablo 2 follows suit with the Diablo 1 in that it doesn’t feature any of the typical iFi “3D” or “XBASS” tweaks, so if you would like to tweak the bass level or sound staging, it would need to be done via EQ or something similar from your source, not on the Diablo 2 itself.




The overall technical performance is again very similar to the Diablo 1. It is slightly more detailed, and slightly more refined sounding than the other Micro iDSD models, but also slightly less easygoing due to this. The dynamic performance of the Diablo 2 is again very similar to the Diablo 1, and slightly more refined and quick than than the other Micro iDSD models.

The build quality of the Diablo 2 is totally acceptable. The new metal case is nice in the hand and has a good, solid, well-built feeling to it. The new, larger volume knob is slightly easier to work with in comparison to the Diablo 2, and the channel matching of the volume pot was also totally ok, with no real imbalance at lower volumes. I also like the new red anodized finish, and think it looks much better than the previous slightly more garish red of the Diablo 1.




Overall, in terms of performance, the Diablo 2 is incredibly similar to its predecessor, the Diablo 1. Very similar sonically, with some nice improvements in terms of build quality, and implementation of features. My main issue is that the MSRP of the Diablo 2 has increased to $1299USD compared to $899USD for the Diablo 1. At $899 for the Diablo one, I felt it was a good product, but was even starting to wonder if it was increasing too much and moving away from iFi’s previous core tenents. I’ve always felt iFi was a brand that delivered very high performance for the asking price, combined with Swiss army knife-like feature sets. Their gear always sounded good, was affordable, and offered a lot of features for the money. The Diablo 2 sort of feels like a car crash with regards to all of those previous things I valued about the brand. The Diablo 2 sounds incredibly similar to the Diablo 1, it has a new feature in the X-MEMS support (but next to no one has X-MEMS IEMs at this point in time) and beyond a new look and slightly better-built case, doesn’t really offer anything of note over the previous version, but costs $400USD more? I like iFi audio, I am a supporter of the brand, and I hope they can quickly course correct and move back to being focused on the things that brought them most of their success in the headphone space in the first place. A focus on quality, affordability, good feature sets, and if a new product is released, to make it a meaningful improvement over the previous version. When you combine this with the fact that Adorama in the USA had the Micro iDSD Signature (Finale) on sale for $350USD brand new, it becomes damn near impossible to recommend the Diablo 2. For me to recommend the Diablo 2, your use case would have to be incredibly specific.

If you

-Use XMEMS IEM’s
-Also use hard-to-drive headphones
-Do not want desktop-size equipment
-Need transportability
-Are not budget limited

then I could make a recommendation for the Diablo 2.

Comparison with the Neo iDSD 2


I don’t dislike the Diablo 2 in terms of its strict sonic performance, it just feels like a missed opportunity for iFi Audio. It still sounds good like its predecessor did, it has great power output for a portable device (with the caveat of the peak vs continuous power taken into account,) and it feels sturdy and well-built. However, the Diablo 2 costs too much at its MSRP, to the point of making me feel that iFi is being opportunistic, and also seems to be a summation of iFi’s abandonment of the company’s previous values and core beliefs. Those previous values and core beliefs about their product lineup and design direction were what made them great, and a fan favourite amongst the headphones enthusiast community. I do have the new Neo iDSD 2 here for review, and I do feel more positively about it than I do the Diablo 2, so I hope iFi is not a lost cause, and the ship can be turned around and get back to heading in a good direction.

Packaging and Build:

The ifi comes in a premium box with plenty of accessories as shown above. The build quality is exceptional, soldi metal build, metal knob has a good feel to it and is accurate, switches and buttons are well made no rattling of any kind with usage. At the time I received my diablo2 the power rating was incorrect and has been updated so I will not mention the specs as they are online. The D2 has a good weight to it but for its size I would say it's not too cumbersome for portable use, I actually have a few shirts where it fits nicely in the pocket believe it or not. I like the included accessories the stiff copper cables worked well and are built durable; I would have liked a little more length to them though. The railings are a nice touch and the desktop and portable mode make this the only combo unit needed in most situations. The case is well made and great in most applications, but I found it a bit too small to include everything inside it. What I like is the design and color, the power and sound signature and its feature rich.
I personally don't care if its 2w or 50w as long as it can drive the headphones to their needed parameters.

Equipment, ETC: I paired the D2 with a small variety of devises, including the TempoTec V6 dap, MY Pixel pro phone, Smasung Phone, Nintendo Switch via Bluetooth, Apple iPad, PC windows and Linux and My Andriod TV.

Performance and Sound:
The Diablo-2 presents with a nice wide and detailed signature with warmth and excellent dynamics. The Midrange is very detailed and natural with most of my headphones and earphones. The treble is also detailed and has a nice airy and sometimes sharp but natural edge to it. It ran my 350-Ohms Fiio FT3, Dekoni Blues, HiFiman Ananda, HE-4X and Sundara as well as a pair of 250-ohms studio and others well.
They sounded bigger in my opinion using this Amplifier.
I must say I really like the very low noise floor of the D2, even with all BA and low impedance IEM it didn't hiss or pop.
The New Bluetooth lossless may be controversial but I will admit it is much better than even LDAC and while I'm not a huge Bluetooth fan I can see this as a convenient way to get good quality playback. Even the hard to drive Tinhifi P1 OG sounded better than I remembered on this unit. I being a hip-dac 1,2,3, ZEN can and Dac and Gryphon user can say the only thing I was missing on the Diablo2 was Xspace and XBass, I think that would have made this just perfect in my eyes. Not that it needs it because dynamics and staging are impressive but more, I like the option being there.



Thinking aloud:
The ifi Diablo-2 is a continuation of the original, I liked the OG as well. I think this one appeals to the music listener who wants something that can do a decent job on desk duty but can also travel with them. Mistakes aside it still has plenty of power and yet is also gentle enough for all BA IEM. Ultimately, it's a well-made all in one unit with great sound and features to boot.

For the last month or so I’ve been using the iFi-Audio Diablo 2 DAC/AMP (D2 from this point) to put it through its paces with my small collection of IEM’s and headphones. Given the power on hand with the D2 I probably don’t have any real power-hungry headphones that fully test its capabilities however I do have ear/headphones that scale well with amplification.

Disclaimer – I was sent the D2 to review, if I keep it I purchase, it is not a gift. I'm also not one for technical data and tech speak, I just try and describe the sound I hear, I leave the tech talk to those with a better knowledge and understanding

A little background, for over 30 years I’ve had a variety of portable players from cassette Walkman's to minidisc players and for the last 15-20 years, DAP’s. In addition to this, since the growth of smartphones I’ve tried many different DAC/AMP products. I think the whole time I’ve been looking for that DAP or smartphone/DAC/AMP combo that I keep longer term.
My current kit is probably the longest I’ve had the same gear for a sustained period of time. DAP wise I’m using a Cayin N7, sometimes on its own and at other times paired with the Cayin C9 amp. This pairing is quite simply the best I’ve heard for its overall presentation of the music and its almost analogue sound.
In recent months I’ve also been using the iFi-Audio Go Pods for a wireless approach with a pair of my custom earphones.
The term portable in reality is different for all of us, when I first started this hobby i used public transport on a daily basis and was often looking for truly portable solutions however in the last few years I’ve leant to drive and no longer really need a pocket set up. This has meant that as is the case with my N7/C9 combo I’ve gone back to larger portable/transportable set ups that are used around the house or go on holidays and trips.

Enter the D2, I never got to try the original Diablo but have owned the Gryphon from ifi-audio and various other portable DAC/Amps from other companies. I was keen to see how this would fare against other products I’ve owned but also how it would perform against my DAP/AMP combo, with an outcome of possibly moving on my N7 if the D2 gets close or surpasses. Although to be honest and I’ll say this upfront I never expected it to be given the price difference. The D2 retails for £1299 compared to the £3000 or so it would cost to buy both Cayin products new.





The D2 comes as quite a premium product in regard to the packaging and included accessories, there is a variety of cables for connection to smartphone as well 2 grey ‘stands/legs’ that attach to the D2 and can be used to stand it an angle, I guess to help keep it cool over extended periods of use. The only downside for me is the included carry bag, although there is plenty of room and it’s a nice addition it just feels a bit cheap to me (but that's maybe just my own taste showing)




The build quality of the D2 is second to none, I’ve found all of the iFi products I’ve owned or used to have excellent build quality and they always feel like a premium product, the D2 is no exception. Everything about the D2 oozes quality, the ridged body, the color and the overall finish are all excellent. Connections are all firm with no looseness, of note is the power/volume dial. This has a small switch/lever design that locks the volume wheel, I find this an excellent addition and adds a sense of reassurance that volume won’t be accidentally ramped up.
Connections are well covered with a 4.4mm Pentaconn balanced headphone out on the front along with a 6.3mm connection. The front of the unit also has the gain selector with 3 settings – normal, turbo and nitro. I think I would’ve preferred it if iFi had just called these low, middle and high but that’s a personal gripe. There is also a xMEMS mode which is specific to headphones/earphones with this technology. I was hoping to buy some earphones to trial with this but could only find one set of earphones with MEMS and that wasn’t readily available.


The back of the D2 has 2 x USB-C, one for charging and one for OTG connection to smartphones. There’s a balanced output along S/PDIF connection. On the underside there is a selector switch for the inbuilt IEM Match, I never used this function so won’t be commenting on it.



For testing I used the following

Fir Audio Rn6
Sony IER Z1R
Grado Rs1x
Sennheiser HD660s
Mitchell and Johnson MJ2
Custom Art FIBA 5 and 7U
I used a mixture of wired connection to my Samsung S23 Ultra smartphone with Qobuz for streaming and the UAPP app for streaming and music stored on my phone.
I used Bluetooth on LDAC setting. Samsung don’t support AptX Lossless so was unable to test this.
I also did some comparisons with my Cayin N7/C9 pairing.

I was going to list some of the components, but it feels like there is a lot of parts to discuss or list so here is a link to the D2 page that describes in better detail than I could.

iFi iDSD Diablo 2 – Portable DAC/Amp for Tidal and Qobuz. (ifi-audio.com)

I’m not going to get into the discussion on review about stated power figures, iFi appear to have rectified the power description on their pages and all I would say is that for me and my usage it packs plenty of power but as a guide my Cayin C9 Amplifier provides stated 2600mW into 32 Ohm and the D2 is stated as 1760mW into the same 32 Ohm. There is a separate max power rating, but this has caused some controversy, so I won’t use those figures.

Onto the sound.
First to say that iFi’s continued use of Burr-Brown DAC pays off again, I’ve yet to hear a Burr-Brown that I’ve not enjoyed. The D2 is no expectation to this.
I tried my Sony Z1r earphones for the first few hours of usage with the D2 using a wired connection to my S23.
For me the sound is very open and airy, with a level of detail to the music that I’ve not heard from many DAPs or DAC/AMP combos that I’ve used before. I think the power from the amp section gives plenty of air and headroom to the z1r that it feels like they have a depth that I’ve only experienced with the C9 before. Those who have heard the z1r will know it has a wonderful sound signature with what I would describe as warm full bass with nice detail although maybe a slight recess in the mids, people often say they don't like this, but I like the sound from them, and they are still a popular earphone years after their release. The D2 has a fairly neutral sound with a slight lift in the mid-treble range, not excessive but enough to give the z1r a lift in the same area.
My Fir Audio Rn6 also fare well with the D2 although they don’t need much volume to drive them, the Sony’s I could easily dial the volume wheel a few notches but not with the Rn6. This is on low gain.
The Rn6 are a hard earphone for me to describe, I see others describe them as a ‘fun’ or ‘musical’ sound however I find them neutral with an emphasis on the bass, due to its kinetic bass, I also at times find them sharp on the treble and this is where the D2/Rn6 can be a bit too revealing on some tracks.
I had similar results with my Grado Rs1x headphones, the Grado sound has quite a crunch in the treble already and the D2 doesn’t tame this, it adds to it slightly but it’s not a bad combo as when the gain is increased it gives the Grado’s even more depth and air and brings out more bass. Some tracks like the Rn6 can be a bit sharp, not sibilant as such just sharp.
Where things change for me is when you use headphones with a warmth similar to the z1r earphone
I used the D2 quite a lot with both the Senn HD660s and the Mitchell and Johnson MJ2.
The Senns have a warm sound to my ears, nice bass with smooth mids but sometimes lacking in the treble region, the D2 changes this a bit and gives them a really nice lift in that area. I was able to listen for hours with the combo of D2/Senn 660s. Smooth, detailed and non-fatiguing especially on the turbo gain which adds more depth and headroom.
The MJ2 are a bit of a strange headphone, initially released at around £500 a few years but heavily discounted when I got them for £95 from Amazon. They use electrostatic and dynamic driver. I’ve always found them a little dark with rolled off treble but a pleasant sound when driven well. The D2 suit them really well, they give them a lift in the treble which they really benefit from.

Bluetooth
I tested Bluetooth most evenings and found it came very close to the sound from a wired connection, used LDAC when connecting to my smartphone. Never had any issues with dropped connection and noted that I was able to get good range around my house with no drops in connection.

Other points
I never had any background hiss or noise with any of my earphones or headphones, always a nice dark background. I never had any use for the IEM match feature but it’s good to know the D2 has it added in case you do have sensitive earphones.
The legs/stand are a good addition to the D2, I only used them a couple of times, but they fix on the ridges to give a stand that I guess some extra cooling.
Battery life is pretty much as advertised, charge time is quite long but can be used when charging.

Comparison
It’s almost an unfair comparison but I’m going to do it anyway.
The Cayin N7 DAP and C9 portable amp has been my go-to for the last 8 months and is probably the best combo I’ve used in many years. The N7 as a DAP is quite unique and gives a wonderful smooth sound quality that has had me hooked from day 1. Paired with the C9 and I have different options such as Class A/AB or Korg options. The C9 is also quite powerful as stated earlier.


In terms of raw power when using the C9 directly against the D2 using Turbo gain on the D2 and switching between low and high on the C9, there is not much difference in power, the D2 feels like it has more instant power whereas the C9 gives a nice steady increase in power which is more gradual.
So, in terms of power to drive headphones I didn’t see a great deal of difference despite a difference in figures.
However, the D2 can’t quite compete with the N7 in terms of sound quality, the N7 is smooth, detailed and almost neutral in its presentation and in reality, is a top-of-the-line DAP that when paired with the C9 takes it to Cayin N8ii levels of sound and power. That though costs over £3000 to achieve that whereas the D2 will only set you back £1299 and is very close in all aspects.
If you weren’t bothered in owning a DAP and wanted an all-in-one solution to connect to your phone either wired or wireless, I don’t think toy can really get any better than the Diablo 2.
Overall the D2 is a wonderful sounding DAC/AMP that beats many DAPs priced higher and is better than any DAC/AMP option I’ve tried before.