iFi Go Bar Kensei Ultra-Portable DAC/Amp Review

The marketplace has no shortage of devices claiming to be that product. Though many are excellent for less demanding headphones or IEMs (in-ear monitors), in general, the better the DAC and amplification, the better the sound for more demanding gear.

iFi Audio is a U.K.-based company known for an exceptional line of portable and desktop DAC/Amps that meet those needs. Kensei is a Japanese honorary title meaning “sword saint” and is given to warriors with exceptional swordsmanship skills. Based on the Go Bar line of portable DAC/Amps, the Go Bar Kensei promises to take an already stellar DAC/Amp to the next level.

iFi Audio is an award-winning audio tech company based in Southport UK. They design, develop and manufacture more than 50 products, including portable audio devices such as the Hip-DAC 3, IDSD Diablo 2, xDSD Portable DAC/Amp, and more.

The Go Bar Kensei is a compact, solid, and luxurious bar-shaped DAC/Amp whose Japanese stainless-steel construction conveys durability. Everything about its build, from the rounded beveled front to the steel buttons on the side reflects premium quality.

I had assumed that for a portable DAC/Amp to deliver enough power for less efficient headphones it would need to be self-powered, like the Earmen Colibri that stole my heart after seeing it at CanJam SoCal 2023. I thought that the Colibri was all I would ever need. And it was, until I had the experience of using the Go Bar Kensei for the last two months. I was amazed at how much high-quality power it generates simply by being plugged into my iPhone or iPad (I did notice it does take a small hit on the battery charge). I grew to appreciate never having to worry about keeping it charged or wondering if it had enough of a charge to last for a long listening session.

The size of an average lighter, the Kensei is packed with sophisticated circuitry including a Cirrus DAC, the JVCKENWOOD K2HD technology, which was designed by Victor Studios (part of Victor Company of Japan or JVC as we know them here) to enhance digital audio to near master quality, four digital filter options, and enhanced clock and power supply circuitry. It sports both a 4.4mm balanced and a 3.5mm S-balanced output.

The Go Bar Kensei has so many buttons and features that at first, I thought it was way smarter than me, and I felt a tiny bit intimidated. Time and practice, however, revealed a DAC/Amp that can be scaled to as simple or complex usage as needed.

The Go Bar Kensei arrived in a compact white box. The colorful graphics are reminiscent of modern Japanese graphic design and included Japanese Shodo calligraphy for the Kensei name. I thought it was classy and simple. Opening the box reveals a stunning hand-carved bamboo box with a lid that slides back to reveal the quick start guide, warranty card, MQA Tidal set-up (though Tidal has recently abandoned MQA from what I hear), and a “thank you” sticker with a happy face character wearing headphones. These are layered on top of a beautiful Japanese paper card, that when removed, reveals a gleaming stainless-steel Kensei, nestled in black foam. I think it is a beautiful presentation. Below that layer is the leather case, and below that are two short cables to connect the Kensei to devices: a USB-C TO USB-C, a USB-C TO USB-Lightning, and a USB-A to C adaptor.

The Kensei is as small as the usual mid-size dongle DAC but has the solid heft of brass knuckles. It’s gorgeous and the Japanese stainless-steel body has rounded edges, the front is a beveled curve, and the flat back is lined with multi-colored LED lights that signal what filters and other features are activated. At one end is the USB-C input and the other end has the balanced 4.4mm and S-balanced 3.5mm outputs. Along one side is a slider that controls IEMatch and buttons that control volume and activate the various features. IEMatch adjusts the output to sensitive IEMs and is switched to the side that matches which output is being used. The center of the switch is the off position and is the position to use when listening to over-ear headphones.

The Kensei sports an advanced bit-perfect Cirrus Logic DAC, that is paired with a custom digital filter that iFi tuned to meet their high standards. The amplifier uses iFi’s “True Balance” circuit design that gives the Kensei nearly 15 times the power of most similarly sized portable DACs. The unbalanced 3.5mm out has dual-mono circuitry that helps reduce crosstalk between the left and right audio channels, thus providing a more balanced-like signal hence the name “S-Balanced”. There are two sound controls, XBass+, which provides more bass and is best with open-back headphones, and XSpace, which expands the sound stage and provides a more holographic feel. I found the effects to be subtle, and I mostly left them off. On the other hand, I was wowed by the option to use K2HD. iFi claims that the Kensei is the world’s first ultraportable DAC that includes K2HD. They worked with JVCKENWOOD for 18 months to adapt K2 Technology to the Kensei. This technology was developed by Victor Studios to restore the digital sub-masters to the warm, rich harmonics of the analog master recordings. The Kensei uses K2HD which is the latest version.

Before I listened with K2HD turned on, I thought the audio provided by the Kensei was very good, and I was using the gain-boost setting to punch up the sound when I thought the music could benefit. I spent several days listening this way. Though excellent, I didn’t think the audio was at a level that would justify the price. There is the build quality of course, which is as good as any high-quality audio device I’ve come across, and the accessories, including the leather case and the bamboo display box, but even so, I felt the price was a bit too high until I activated the K2HD. It was as though the proverbial veil was lifted from the music. This one technology delivered what the XBass+, XSpace, and gain-boost promised. It lifted the audio to a level that seemed to reveal detail and life to the Sennheiser IE 900 and even the Arya Organics, though I think the Kensei is a perfect match for IEMs. To access K2HD, you hold down the set-up button for 3 seconds, wait for the MQA light to flash, and then press the + volume button. To turn it off, you repeat the process. Why anyone would want to turn it off I don’t know, unless it draws down the battery of the device it is plugged into more than with it off. I’m guessing that the internal amplifier pulls more power from the audio device as more filters and features are turned on.

Not only does the Kensei deliver generous power, but stunning detail-rich and dynamic audio. Both the HIFIMAN Arya Organic and the Sennheiser IE 900, two of my favorite over and in-ear headphones prefer a little extra juice to perform well, and both sounded full and dynamic when powered by the Kensei, especially when the K2HD filter was on.

There are various combinations of buttons to activate the filters, and it took me some time to get comfortable with all the button pushing, but it soon became second nature. Honestly though, I skipped almost everything, even the various formats, and was more than happy with the K2HD feature. Someone with a more trained ear might make better use of the filters than I could. I will leave detailed instructions on how to activate the various features to the online manual.

The initial setup was straightforward. I used the included USB-C to USB-C cable to connect the Kensei to both my iPhone and iPad. I liked the short cable as it made for a compact set-up. I also used the 4.4mm balanced output for both of my headphones to take advantage of twice the power it provides. Just out of curiosity I also listened to the HIFIMAN Susvara Unveiled through the Kensei and was impressed at the volume, which was more than enough. However, the Susvara Unveiled needs a desktop amplifier to provide the power to bring out the dynamics and magic, so, though the Kensei can do a great job of allowing it to become a semi- portable headphone, the Susvara asks for more than any ultra-portable DAC/Amp can provide.

I puzzled over the leather case. It is nicely made, with a magnetic closure and belt loop, but it lacks versatility. It would be nice to use the Kensei while it’s in its case, but there isn’t any access port built into it. It is simply for protecting it. Though the Kensei is tiny, it is heavy for its size, and there are many smaller dongle DACS that are lighter and more compact, and if pocket-ability is the main concern, there are other devices on the market that might be a better fit.

In addition to the Arya Organic, Susvara Unveiled, (both planar magnetic, which are more difficult to drive), and the Sennheiser IE 900, I also spent time listening to the Meze Empyrean ll (an over-ear planar magnetic headphone) with the Kensei and my iPhone and iPad. The Empyrean are efficient and fairly easy to drive, and sounded quite good, especially with K2HD active. In many ways, this ultraportable DAC/amp sounds like a mini desktop amplifier. I did notice that the Kensei gets warm which I would think highlights the fact that there is a powerful amplifier working underneath the Japanese stainless steel. I also think the stainless steel might be prone to scratches, so I recommend keeping it in the leather case when not in use.

The best combo was the Sennheiser IE 900. The IE 900 is already a beautiful-sounding IEM. In fact, the Kensei is a perfect match for IEMs, and I think that the IE 900 came alive with the Kensei, and the two make a fabulous travel pair that provides stellar audio on the go. When I reviewed the Sennheiser IE 900, I commented on the impactful bass, wide soundstage (for an IEM) and crystal highs. The mids were fine, though somewhat muted. However, when paired with the Kensei and K2HD, they took on another level of detail and dynamics. Vocals, especially, sounded even more intimate and textured.

If I were to use an analogy, I would say that the Go Bar Kensei is like an audio magnifying glass that reveals all the detail and nuance in music files.

The iFi Go Bar Kensei fills a niche in the ultra-portable DAC/Amp market. Though a major purchase, it is an investment that will bring out the best in IEMs. Built to last, and beautifully engineered, I think it has a unique spot in a crowded marketplace. If coaxing the last bit of detail and musicality from your headphones while listening to mobile devices is high on your list, this precision-built, ultra-portable DAC/Amp can deliver.