iFi's xDSD

It has always proved exciting for me to receive an email from iFi, and the same held true when they reached out to me regarding their new xDSD portable DAC/amplifier. This entry to the market seems to seek to directly compete with offerings from similar boutique audio companies, like the Chord Mojo, which I reviewed many months ago. Regrettably, the device has since left my hands, so I won’t be able to do a direct comparison. However, continue we must.

Thankfully, I’ve got a few hours on a high-speed train, which after many hours of casual listening, should leave me enough time to faithfully put this through its paces.


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My intuition says that the design that iFi has shot for with this device will be fairly polarizing. I’ve tried to keep my eyes off of other reviews of this, for the sake of providing the most uncolored review that I could provide, so I can’t say whether or not that assertion holds.

I, personally, am a fan of the design. The two-tone colorway seems tasteful and understated (or rather, not too overstated), and the finish on the majority of the device, although certainly prone to fingerprints, is very obvious of high quality. I do wish that the main volume adjustment knob was also metal, but the plastic used is finished well, and has no machining errors.

The other cue that warranted the above mention of the Chord Mojo is the lighting on this device. The input-type and signal quality LED indicators are both multicolor, very similar to the indication used on the Mojo. Just as the Mojo does, the color of the volume knob’s interior on the xDSD changes as the user progressively adjusts the volume.

Aside from the 1/8th inch TRS signal output on the front, the only other button rotates through iFi’s XBass+ and 3D+ settings. These are both ASPs which, respectively, increase the bass levels and attempt to widen the soundstage. I’ve seen these two ASPs on every iFi device I’ve received, of note being the iDSD Black Label and the iFi Pro iCan. I’ll touch on how they work in the sound section below.

In terms of inputs, those sit on the back of the device. There’s an embedded male USB-A type, just as with the iDSD Black Label, and included is a cable for the same, since that’s such a rare connector type. To my intuition, the logic behind including that, as opposed to a female port, is that this connection is less likely to physically fail by stress on the connection.

Other connectors include a S/PDIF connector for signal input, and a female micro-USB port that is used exclusively for charging.

There is also a switch on the back, which switches between two digital filters for PCM and DSD files – one is transient optimized minimum-phase (“Listen”), while the other is frequency response optimized (“Measure”). These did not come into play in my testing; I, personally, feel that any improvements heard in files with bitrates/bitdepths higher than ~1400 kbps/16-bit are either entirely spurious or the result of better mixing and mastering on those files than on the same in a lower bitrate/bitdepth format. Apologies if this is offensive to any of my readers, but to those that it is, I invite you to take a blinded ABX test with your favorite, most frequently-listened-to tracks between ~1400kbps/16-bit FLAC and your preferred brand of snake oil.

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Sound (and Acoustic Design)

Here's the hard part of any DAC/amp review for me: I have yet to see any significant evidence that, beyond competent performance, increasing the price of components and the price of the device will make the experience of using a DAC or amplifier better.

This is controversial, of which I am aware, especially for someone whose job it is to review audio products. It being controversial does not change the fact that it is likely true. For 99.99% of the population, in a double blinded test setting in comparing just amplifiers or just DACs, I guarantee that there would be no observable difference. Perhaps there are very small triggers that, for those who are extremely familiar with a given product, may allow them to distinguish between some, but I feel that the difference experienced and often commented on by reviewers between amplifiers and DACs is exaggerated to the extreme. I also feel that these differences are more often than not the result of imperfect sound-level balancing between the products being tested, as that seems a much more likely cause as opposed to a circuit which, electrically speaking, is just increasing the amplitude of a signal.

The reason that I'm belaboring this point so heavily is that I feel it is disingenuous as a reviewer to say otherwise. It is unfair to my readership (however small) to present a difference which I, frankly, cannot observe (and one which I believe very few, if any, can genuinely observe).

All this is not to say that there are no differences between DACs/amplifiers. Products have different feature-sets, and sure as day some of them do not perform competently. Some have horrible crosstalk, some have horrible SNR ratios, some have horrible bugs and flaws that only come out in experience. This is what I try to speak to in my reviewing, because this is how (I believe) decisions about these products should be made.

Diatribe out of the way, I'll get back to talking about the product at hand.

iFi has done a very good job here. The amplification is clean and free of any noticeable flaws. Simply because it seems to be the goal use of the product (portability considered), I spent most of my reviewing time with the device paired via Bluetooth to either my laptop (sending signal as FLAC) or my phone (as 320 kpbs MP3). My laptop is enrolled in a beta program, so I experienced some Bluetooth errors with it, but that is not the fault of iFi. With my phone, I experienced essentially no issues, although interestingly, you can hear some dial-up reminiscent electrical noise upon starting the device up. That, however, disappears quickly and is a non-issue, thankfully.

One of my favorite parts of any iFi product are their ASPs. These are Analogue Signal Processors which, as opposed to digitally manipulating the signal to increase bass or apparent width, use analogue components to achieve the same results. In my experience, these implementations tend to work considerably better and produce markedly better results than digital alternatives.

The same is true in this case, and I enjoy both exactly as I did in previous iFi products that I've reviewed. Linked as follows are my reviews of iFi's iDSD Micro Black Label and Pro iCan, if anyone reading would like some more expanded comments on these functions in past devices. I found that the effects of both were practically the same, although slightly less intense in this device.

One thing that I would like to note, for those to whom this is relevant, is that iFi has gone every extra mile to pack this device full of the best components accessible, price-irrelevant. This is something that I've consistently and constantly seen iFi do, and something that I respect greatly. As is clear from my above rant about reviewing DACs and amplifiers, I am not one to ascribe too much value to the technical specifications of any amplifications device, but for a very reasonable price (in this case), iFi has included the best of every single component for their customers.

The reason I bring that up is that I respect that people (especially those reading) may have different opinions from me. That's perfectly fine and perfectly normal. I bring up the things that I do and meta-comment as much as I do so that the reader can have a better understanding of where I come from and what my mentality in reviewing is. If you are someone to whom technical excellence matters (as I, usually, am), this is the device for you, and even more so, iFi is likely the brand for you.


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Alright, this has been a long and strange review to write. There's been a lot of meta-commentary, and for that I apologize, although I feel that it was warranted in the places that I put it.

In summation and conclusion, this is an excellent device. It performs extraordinarily well for its price point and form factor. It is built from the very best components, with every thought given to how the inclusion of Bluetooth and other portability-oriented considerations will affect the sound (and more particularly, how iFi can avoid any of the many downsides that usually come with this probability).

I feel that the design is very pretty, and that the form factor is good. Others may disagree, but that comes down exclusively to personal preference. The included ASPs are as great as they have always been in past products, and offer an edge over potential competition, as I rarely see ASPs in products this small. The device is powerful and clean enough to suitably power pretty much any headphone that I could reasonably see someone wanting to use portably.

If I had to make an ad-hoc comparison to the Chord Mojo, since these devices seem to share a lot (most relevantly, likely including target customers), I would give this device the edge. It simply has more features with a similarly excellent implementation. The two features that edge it out over the Mojo, for me, are the inclusion of Bluetooth and the ASPs.

Thanks so much to iFi for sending this over to me! I excitedly await the next product I'll get from them, as I've yet to be disappointed.


This product was provided to me for review by iFi Audio. I am not being paid by anyone to write this review, to endorse the product reviewed, or for the content that I put in the review.

The signal for this device was provided by my MacBook Pro and my Google Pixel.

I have had this product for about two months, and have used it for about 50 hours.

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