There is a very slight audible hiss when used on extremely efficient speakers, but did not notice it on my KLH model 6's. The Amperex preamp tubes make the soundstage very open and 3 dimensional. It has been my main unit and has been used quite frequently in the past few years. I mainly used it with a variac, but also without and had no issues. The tubes are matched and well balanced.
Also note, I utilized an adapter and have the less expensive, easier to get your hands on 6GH8A tubes instead of the 7199 tubes in the unit. Again, please contact me with any questions. The item "SCOTT LK-72 Tube Amp completely refurbished Amperex 12AX7 preamp tubes Exc cond" is in sale since Sunday, November 17, 2019.
This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Amplifiers & Tube Amps". The seller is "roli-wad" and is located in Stow, Ohio. This item can be shipped to United States.