The combination of incredible performance and limited availability have given MASS-Kobo almost legendary status among audiophile headphone enthusiasts. Each unit is handmade by one man, Mr. Masuda, who also painstakingly selects each individual component that goes into the amp, only after personally testing them. The end result? Great amps and long wait times. We finally got our hands on the MASS-Kobo 465-044, and now we’re ready to find out, is it worth the wait and all the hype?
Build and Design
On the surface, the MASS-Kobo looks like any number of high-end components, with a vintage aesthetic rooted in 70s HiFi. In fact, the brushed aluminum face and light up buttons wouldn’t look out of place in the cockpit of an X-Wing fighter or the Millenium Falcon. The aluminum chassis feels sturdy enough for space battles too; the case, panels, and connectors are all very well built and designed. Each button on the front panel has a bright green glow to indicate which gain, input, and output options you have selected. The inputs and outputs have to be independently selected, so you can’t, for example, listen to both the 4-pin XLR and 6.3mm outputs at the same time.
In terms of power 455-044 outputs a maximum of 4.5W into 32ohms, with an RMS of 3.8W. The design uses a high impedance output which provides stronger performance with lower sensitivity headphones than you would expect given the raw wattage number. Where some amps produce power in excess of 20W per channel for the purpose of driving headphones like Susvara, MASS-Kobo’s high output impedance solves the same problem with less than 5W.
Part of what makes MASS-Kobo amps stand out from other products is that the component selection doesn’t just come down to selecting the brand and model of each component; Masuda tests each specific, individual component before he puts it into the amp to ensure that it’s up to spec and that all components in the amp are perfectly matched. It’s this sort of attention to detail in the small things that makes the handmade 455-044 so sought after.
Sound
MASS-Kobo 455-044 delivers an exceedingly clean, detailed, linear sound without even a hint of color with most headphones. The linear, low noise floor, and low harmonic distortion are the hallmarks of MASS-Kobo’s design. Above all else, 455-044 gives you transparency with power. It won’t change your headphones, but it will push them to the limits of what they can provide in terms of soundstage, separation, and dynamics. The pure technical performance that you get from the HIFIMAN Susvara and Susvara Unveiled puts this amp in the top tier of headphones on the market, while that transparent performance means it will pair perfectly with the rest of your headphones as well.
Because of the high output impedance, some highly sensitive headphones and most IEMs will experience some level of change to the frequency response depending on what the impedance curve looks like, but will most likely add more bass. Even though there is some impact to the frequency response, 455-044’s ultra-low noise floor means it remains dead quiet with all but the most sensitive IEMs.
To really get a feel for the MASS-Kobo, I lined up a selection of headphones including the Sennheiser HD650, Meze 109 Pro, Audeze LCD-2, Meze Elite, DCA E3, HIFIMAN Susvara, and HIFIMAN Susvara Unveiled. With each headphone, 455-044 offered improvements in the spatial characteristics and dynamics compared to what I’d heard before, and improvements in the bass slam were noticeable in the planar magnetic headphones. While other headphones felt improved – even compared to other high-end headphone options like the Burson Conductor GT4 – the original Susvara feels positively transformed with this combination of expertly crafted power.
One of my test tracks was “Exile” by Taylor Swift, which features guest vocals by Bon Iver. The weight and realism in those vocals, particularly with the combination of the dCS Lina DAC and HIFIMAN Susvara or Susvara Unveiled was unmatched. MASS-Kobo literally just dropped you into the studio, putting your head right there, in place of the mic. Both the detail and the imaging were at the absolute top of anything I’ve ever heard.
The bass was equally as impressive as the detail and imaging. Listening to “Everything in its Right Place” by Radiohead with Susvara Unveiled, the deep weighty low drones from the electric piano have a constant weight to them, but the rest of the space is wide open as the lilting vocals, and glitchy samples build around it. Daft Punk’s “Doin’ it Right” provides a more direct test of the MASS-Kobo’s bass capabilities, and it does a brilliant job of eliminating any sense of roll-off in the subbass with Susvara.
The soundstage and separation are even more impressive with classical music. Listening to the Los Angeles Philharmonic’s recording of Holst’s The Planets, 455-044 combined with Susvara Unveiled offered the sort of massive, epic feeling pieces like “Mars, the Bringer of War” need. The full dynamic range – and ultra-low noise floor – are also on display here, delivering the build-up and climax with a range that you almost can’t believe is coming from headphones.
Comparison: Cayin Soul 170HA
Both are high-end, purpose-built solutions for high-end headphones that offer extreme power and detailed, accurate sound, but there’s a lot more that’s different than there is the same between MASS-Kobo 455-044 and Cayin Soul 170HA.
Probably the most noticeable difference – other than the price – is the size. Soul is easily 4x the size of 455-044, and more than 4x as heavy. But if the size isn’t a big deal for you, the all tube Soul looks much more impressive. The device chassis and controls have a more luxurious design and a stronger sense of style.
Even without going through all the features, we all know that it’s the sound that really matters, and the difference here is bound to be divisive. MASS-Kobo’s sound is pristine and transparent to the maximum degree, so while Soul offers what you might perceive as transparency at first, compared to 455-044, there’s a clear warmth and sense of elevated body in the Soul. Soul also can’t keep up with the dynamics and immediacy of MASS-Kobo. Planars in particular hit with a speed and dynamic force with 455-044 that Soul can’t keep up with.
Purely as a solution for getting the most of out of Susvara, MASS-Kobo 455-044 is the better solution, but if you like a little extra body and warmth to the sound rather than the perfectly pristine sound of 045-044, then Soul is among the best headphone amps out there.
FInal Thoughts
Anything more than a quick glance at its minimalist design will reveal that a deep level of attention to detail and care goes into every part of MASS-Kobo’s products – from the engineering to the selection of components and final construction. It’s a privilege to hear the final result of a design and build process that demonstrates so much love for the simple practice of listening to music. What makes it truly special is how this love and care is coupled with expertise and mastery. MASS-Kobo 455-044 delivers an incredible audio experience, and a level of sound quality that few products could hope to match.
