Yamamoto A-08S, It’s quiet, so very quiet and almost totally noise free which is a true pleasure. The only other pure tube amplifier I have had that is capable of this level of quiet, hiss free operation is the Radu Tarta Shiny Eyes.
With the K-horns I had to have my ear all the way up to the tweeter to hear a very tiny bit of hiss and those are 104 db sensitive. My Spatial Audio speakers are not sensitive enough to produce any hiss, so as you fall into the 96db - 98db mark consider this amplifier noise free. At over 100db the noise on mine is minimal, barely perceptible. 
The midrange tone and presentation is to die for, I expected no less. I honestly can see a pair of Omega, Charney Audio, Lii Song Reference, Voxative, Lowthars, Altec, or Zu speakers and a Yamamoto amplifier being a 95% solution to the desires of “1-WATT” lovers. Hell, even most DIY open baffles would probably sound satisfying w/ this amplifier, its presentation is just so alluring.
The build and quality is not only exceptional but it is also very much aesthetically pleasing to me 
. Pretty much every part is made in-house and the fit and finish exudes precision and luxury well exceeding the cost to purchase, which makes these hidden value gems 
in my opinion.
I want to own all his builds in the various tube configurations he has produced some day, I am a fan of the sound signature and character he is going after, I will require at least one more pair of speakers of about 98-101 db sensitivity that are not horns to appreciate and enjoy some of the finer capabilities of this amplifier.
Now the part that hurts my soul to say out loud, the Yamamoto does NOT beat out the more impactful, weighted performance of the Alan Eaton design, nor does it capture the grand stage and very airy almost dainty upper end character of the Radu Tarta. 
The Yamamoto has performance characteristics very similar to the Decware SE84UFO25 (maxed out edition) w/ a bit more weight but not the superb weight of the Alan Eaton.
The Alan Eaton design continues to reign supreme IN-MY-HOME, shortcomings and all. Alan Eaton amplifiers are the Luciano Pavarotti’s of tube based, flea-watt, 1-WATT designs and the 45 tube in my opinion & home rules them all. (At least for today, there’s so much more out there I have not played w/ yet 
