iFi xDSD Review – Multi-purpose High-end Portable Bluetooth Amplifier for Headphones, Laptops, Smartphones and Digital Players

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iFi is no stranger to the portable audio market, and the 'X' series marks another step in the company's development for delivering the highest quality of innovation, from design to functionality. As the first product in this series, the xDSD portable headphone DAC/amplifier, is the company's very first Bluetooth device. It's convenient, compact, stylish, and works so well that you can't complain about its setup. However, the question we want to answer in this review is: who should buy the iFi xDSD headphone amplifier and why?


iFi xDSD Versatile High-performance DAC/AMP Review

DAC: BurrBrown DSD1793 | Maximum USB resolution: 768kHz/24-bit, DSD512 | Maximum S/PDIF resolution: 192kHz/24-bit | Dynamic range: > 113dB min | Output power: > 2.82V/500mW @ 16 Ohms, 3.8V/24mW @ 600 Ohms | Total harmonic distortion + noise: <0.005 | Output impedance: <1Ohm | Bluetooth codec: aptX, AAC | Battery: 3.8V, 2200mAh (up to 10 hours via S/PDIF, up to 8 hours via Bluetooth, up to 6 hours via USB | Dimensions: 95mm x 66.5mm x 19mm | Weight: 127g



To be completed



In addition to the soft case, the kit includes various adapters – from USB to optical 3.5 mm.

  • Three different USB wires/adapters
  • Adapter for S/PDIF output
  • Self-adhesive “sticky” pads to attach the device to the source

As you can see, everything you need is included in the kit.


Before introducing the X series, the manufacturer kept the same basic design and only changed the dimensions. With its metal casing, dark chrome, and beautiful grooves, the xDSD has the most unusual design iFi has ever created, so it was time for a change.

It’s not the type of USB stick DAC you slip out of your hand. However, it is significantly smaller than Micro, which the company couldn’t figure out how to make it smaller. Also, instead of brushed aluminum, now we have a ridged surface with dark chrome. This solution, however, rather quickly collects fingerprints but also quickly gets rid of them when cleaning.

The xDSD is a bit large for a “pocket” device, but the wireless module makes it portable enough. However, in the case of a wired connection, you will probably need a carrying bag to carry both the amplifier and audio source.

You’ll find connectors controls at both ends of the device: a pair of USB ports and a universal connector, particularly from the older model that retained the implementation of a balanced headphone connection. And, judging by the specs, the power will be enough.

All controls are located on the front and back of the device. Let’s start with the rear panel.

  • S/PDIF input
  • The USB input for connecting digital sources comes in the form of a recessed plug, making it easy to use Apple’s USB adapters and various USB OTG adapters.
  • Filter switch
  • MicroUSB socket for charging and LED indicator for battery charge.

On the front:

  • 3.5mm headphone output compatible with 4-pin balanced connector and conventional connector with common ground
  • Two different colored LEDs indicate the selected input and signal frequency (including MQA)
  • The volume control is the main control and consists of buttons and LEDs.
  • Two LEDs indicate the 3D+ and Xbass+ modes.
  • The button for switching between 3D+ and Xbass+ modes also supports Bluetooth pairing mode.

The xDSD does not amplify the analog signal but only outputs it via USB or SPDIF. The latter connects to a universal mini-jack socket, which can be made up of optical and coaxial cables.

Overall, despite the interesting LEDs that change color when changing the volume (there are seven, with red indicating “loudest”), this amplifier is very intuitive. In addition, the status and type of connection are also indicated by colored LEDs.

For example, the USB is white, Bluetooth is blue, and SPDIF is green. The other LEDs light up green until 96 kHz, then turn yellow, and finally light up white for DSD.


The xDSD uses the popular Burr Brown DSD1793 chip. iFi Micro offers a similar converter with three filter options. This time the NOS mode (called “Bit Perfect” on the Micro) has been removed, and only two listening modes remain, “Measure” and “Listen.”

In essence, the specifications of the device are very promising. However, we are talking about the frequency response of the XMOS USB receiver, not the Burr Brown DSD1793, which can handle DSD64 and PCM signals up to 192 kHz.

Now about the sound paths, the XBass+ and 3D Matrix+ boost bass and channel crossover, respectively, without affecting other parameters, and do so quite accurately, according to measurements: +9dB at 9kHz for XBass and 12dB of channel separation in 3D. In 3D, the channel separation is reduced to 12dB.

The low-level signal (-90dB) is very well reproduced in xDSD and is not drowned in noise. In general, despite its age, the Burr-Brown PCM179* series always has this parameter in order thanks to the separate processing of the upper 6 and 18 bits.

As far as the power supply is concerned, the decision to separate the inputs for charging and content is a very good one. This reduces crosstalk and saves the signal source’s battery: in USB mode, xDSD can run for more than six hours, depending on the load. A full battery charge takes about three hours, maybe a little longer.

Bluetooth quality is also good, with a range of 10 meters. As long as there are no solid walls in the way, it works well. Other reviewers have complained about the stability of the wireless connection, but I haven’t had any problems, so I guess that counts for the source as well.


The SoundSurge 90 headphones feature hybrid ANC, which uses both internal and external microphones to eliminate noise inside and outside the ear cups, providing more effective noise cancellation performance than the Feedback mic solution in the SoundSurge 85.

TaoTronics claims that its hybrid ANC can reduce ambient noise by up to 30dB, and performance is good. I’ve found these headphones do a decent job of blocking unwanted distractions, especially sounds that fall into the mid and low range during conversations. The words were indistinguishable, and the regular voices were lost behind the combination of music and ANC.


As with all TaoTronics over-ear ANC headphones, the SoundSurge 90 uses dynamic drivers with a diameter of 40 mm. In the case of this model, the manufacturer advertises a “deep bass.” The SoundSurge 90 offers good sound for a budget pair of headphones, and it’s clear they can handle a range of genres.

In the test, the TaoTronics SoundSurge 90, like the SoundSurge 85 recently, disappointed me a bit. Unfortunately, I can’t relate to the manufacturer’s promised “deep bass.” On the contrary, it seems pretty superficial to me. So sub-basses are actually not audible, and the bass frequencies don’t appear particularly voluminous. The headphones are similarly weak in the treble area. Here, details and nuances are often simply drowned in mid-tones, which I find a shame. Especially since TaoTronics has already proven with the TT-BH046 ANC headphones that they can do better – annoying!

TaoTronics SoundSurge 90 benefits from plenty of room for the instruments to breathe and has a strong midrange so that voices are beautifully present. Simultaneously, many details are lost in both the low and high frequencies, which means that every musical direction simply sounds very flat.

These headphones offer fantastic sound reproduction and detail for their price, but the tonal balance leaves to be desired. While these headphones won’t appeal to audiophiles, they are more than enough to keep most listeners happy.

Compared to the TaoTronics SoundSurge 85, I even like its bass overall better because it can reproduce some frequencies more uniquely. Otherwise, I would recommend the TaoTronics TT-BH046 or the Soundcore Life Q20 in the price range, both of which I like better in terms of sound.

Overall 3.4/5

The TaoTronics SoundSurge 90 is a fantastic pair of budget headphones. For under $ 80, you get ANC, long battery life, fast charging, and the latest Bluetooth standard.

The best features here are the lightweight, comfortable design and the long battery life. Both of these qualities make the SoundSurge 90 perfect for travel, while the fast charge feature means you hardly ever have to worry about not having music on shorter trips and commuting. Hybrid ANC is also impressive and does a great job of blocking unwanted traffic and chatter.

The reproduction of the sound isn’t outstanding next to the more expensive pairs, but it outperforms various budget competitors. If you’re not much of an audiophile and more looking for a pair of dynamic headphones to wear in stores or attenuate the conversation noises in the office, the SoundSurge 90 won’t disappoint.



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