[rfeenstra]

Well, it didn't sit on the shelf. It went to the bench.  Replaced all the tubular and lytic caps, several resistors  that were actually within spec, but did it for grins and giggles cuz they were in bias and balanced circuits, one open power resistor, 4 matched output tubes, and one bias supply selenium rectifier. I had to add a bit of resistance to the the bias supply to compensate for the silicone rectifiers. I didn't re-stuff the old caps as the new caps were actually larger than the originals (physically), but they didn't look all that different anyway. I got a kit of lytics from Hayseed Hamfest. They had a twist-lock kit for this amp. They look different but I'm looking for performance, not original appearance for this amp. I set bias and balance for the the 7591A's ( boy do those things generate heat!) and ran a sine wave signal through the amp.  I noticed that the sine wave was slightly miss-shaped on one channel.  Turns out I didn't do quite as good a job building as I originally thought.  Found a slight wiring error in the preamp section that accounted for the slightly distorted waveform.  I didn't have a scope or signal generator in my grade-school days!  Once that was fixed, I started doing some power/distortion tests when I started seeing some very strange wave-forms on one channel on the scope.  A 6u8 died.  Now I have to wait for a matched pair of 6u8's. Original 12ax7's and 6u8's were Telefunken's.  Don't know what I'll be getting for replacements of the 6u8's.  I replaced the 7591A's with new, Russian made TungSol's.  Review's seem ok, but we'll see.  At least they are the same physical size as the original tubes. I'll hook this amp up to my DAW  in my sound studio to see how it compares to more modern stuff.  I suspect I will be disappointed, but we'll see!