Paul, I will not take anymore of your valuable time. I will end by giving you the current transformer wiring. upper xformer , Red is from high voltage of power supply. blue lead comes from pin 2 orange connects to pin 3, . green from upper, goes thru a 220 uf, electrolytic bypassed with a 270K resistor to gnd. the small output has a connection from pin 3 thru a 3.3 solen to the orange lead. bl.,brn,red,yel are not connected. Out put to binding posts is via blk. and 16 ohm yel. to speakers. I am going to have to wait several weeks for the x formers the tfa 204s to arrive. Thanks you so much for your help,I have really learned alot,and as you have noticed I have alot to learn. You are so kind to share your knowlege with me. J.
It's no problem, I am genuinely interested in seeing you get this thing working. Sometimes I make short answers when I'm in a hurry, so apologies if I seemed curt.
The reason I asked for tube voltages is to be sure all four tube sections (two per tube) are operating correctly. The high voltage (453 vs. 410 expected) might be caused by one section failing to draw enough current. Check the voltages at the actual tube socket pins, don't rely on wires that connect one socket to the other - there could be a bad connection or a broken wire.
The old output transformer (now the plate choke with feedback coil) appears to be connected correctly. I assume the "270K" resistor is actually 270 ohms? I would encourage you to raise it to 390 ohms, 5 watts. The higher wattage will give a longer life, and the higher resistance will reduce the total current through the plate choke, reducing its distortion.
From your description, there is only one lead of the small output transformer connected, so it's no wonder there is no sound. The 3.3uF Solen should go from pin 2 of the tube socket (NOT pin 3) to the orange lead of the transformer (I assume that it the lead marked "1.25 watts" on the transformer). The black lead of that bundle is shown in ref 3 going to ground.
Your numbers show 155 volts across the 6K resistor (453-298), which by Ohm's Law would be about 26mA current. This would be 4 watts dissipation, exceeding the rating - no wonder it is hot! Best to check the resistance in case the heat has damaged the resistor. I would encourage you to replace it with a 6K 5watt resistor - but not until we get the high voltage down to where we expect it to be. But the circuit says you should have only 18mA (total of 16mA to tube pin 5, and 2mA through the three 50K resistors on the PC board). The plate voltage is close enough (225v vs. 250v expected) so I expect the 16mA is correct - leading me to suspect the 50K resistors may not be wired in series. The old boards were very confusing in that area, so it's worth inspecting them. There should be three resistors in series, with 100v across each one (adding up to 300 volts across the string).
Incidentally, I do recognize how much of a pain it is to be entirely clear and complete in posts like these, where we can't see what the other is doing. But we are usually successful eventually!
