I am replacing the power supply caps and also relocating some of the filtration closer to the PC boards. These amps have long wires running all over. They also have woefully inadequate grounding. I will be shortening up wires and adding grounds. I have also rewires the high voltage supply to change how the stand by works and to add a high voltage fuse. The amp has, for some reason, a second fuse in series with the main fuse. It's inside and permanently soldered in place. I have removed it. The "polarity" switch is for use with ungrounded AC supplies and puts one side or the other of the mains to the chassis through a capacitor. We call these death caps. This bullshit has been removed. The switch will remain for cosmetics.
Observe the following graphic images.
The amp chassis as delivered. Parts that will be changed are the two blue chassis mount caps, the silver cap next to the PC board and the black chassis mount cap way up in the upper left corner.
This view shows the new B+ fuse (1 amp fast blow) next to the original fuse. Note the internal fuse has been removed. To the left are two resistors added for filament hum balance. This takes the place of the hum balance pot. To the left foreground is a pot that will become the new adjustable bias pot.
The two replacement chassis mount caps for the plate supply. The resistor has been moved from where it was near the black chassis mount cap. The small cap takes the place of one section of that cap. The other sections will be replaced by caps placed on the PC board. This shortens up several power supply wires. The pot above the tube socket is the hum balance and will be removed.
Here are the new screen supply caps.
Next I will hook up the bias pot and mount the remaining filters somewhere, add some grounding and fire it up. My initial tests with some used Phillips 6L6s showed it to be down on power. The next power test with the new caps and tubes should prove interesting.
"Tyranny, like hell, is not easily conquered… What we obtain too cheap, we esteem too lightly: it is dearness only that gives every thing its value. Heaven knows how to put a proper price upon its goods; and it would be strange indeed if so celestial an article as FREEDOM should not be highly rated."
-Thomas Paine
