Matsuda-san of MASS-Kobo and myself have somehow missed each other over the past 2 years. During the 2019 Autumn Festival, I was finally able to experience the range of headphone amplifiers put together by Matsuda-san, a highly respected Japanese sound engineer.
In my review of the HiFiMan Susvara, I mentioned that there is a lack of headphone amplifiers that could power the Susvara properly, the only amplifier that could do so is the Leptoni DT-Reference. Following my experience with the MASS-Kobo model 406, I am pleased to say that there is now a second headphone amplifier (and the only solid-state amplifier) which in my opinion is able to power the Susvara properly (powering a pair of headphones properly and having sound is two matters altogether).
In the short time spent with the MASS-Kobo products, I have to say I was very impressed with the work of Matsuda-san. They are definitely amongst the best sounding solid-state headphone amplifiers that I have heard and I can’t wait to spend more time with them.