Knight KN 755
Back in the early 90's I was headed to work and saw this sitting on a neighbors dumpster and as I drove by I didn't pay much attention thinking it was an early solid state.
After passing by it I glanced in the mirror and to my surprise I saw tubes sticking out the back.
I spun around and picked it up and brought it home.
My find turned out to be the best tube amp I have ever owned.
Powered by 4 6L6's it's rated 55 per channel. After changing every cap and swapping out the old 6L6's for new 5881 W version tubes it has been my amp of choice and perfect for driving my D120 speakers.
Clean and quiet, the Knight has been very reliable and the audio is second to none.
The only drawback is these units run really hot. Since the finals are mounted horizontal there is a lot of heat dumped in the rear portion of these amps. I ended up placing a small fan behind the unit so when its running there's air forced thru it. This made a huge change in the temperature of the case and the transformer. I'm sure many of these suffered transformer failures from the heat they generate.
Without the fan the rear case will get so hot it will actually burn your hand.
They run HOT! if you own one of these get a fan or all that heat in time will kill it.
KN 755 Schematic