This is quite a little performer,
The sound is crystal clear, there's no hum, hiss or noise of any kind, the stereo imaging is wide and precise to the point where I can close my eyes and point out the instruments and vocals in the space in front of me. And the sound is very rich and warm.
I swapped the 15V AC on the PSU for the filament heater to 9V AC, and the heat sink (while still warm) is cool enough that there won't be any need for extra cooling.
Besides, who can resist that little glow peeking at you? All in all, this is full tube/valve Class A sweetness :)