Single ended amplifier power supply. The grounding prong of the power plug goes to both chassis and circuit ground. The neutral prong goes to the bottom of the power transformer primary. The hot prong goes through a fuse then a switch then what appears to be a thermistor to the top of the primary. There are 2 heater windings on this transformer. One goes to the heater of a 6 T 9. There is a 1 k ohm resistor going from each side of this winding to a point labeled eh. The other heater winding has a center tap which connects to point B. This winding goes to a KT88 and two 5687s. The top end of the winding goes to the anode of a diode. The cathode goes to one end of a capacitor, the other end goes to the bottom of the winding. The cathode of the diode goes through a 1 k ohm resistor to the anode of an L E D. The cathode of the L E D goes to the bottom of the winding. The center tap of the B plus winding goes to circuit ground. There is a 0.01 u f 1200 volt cap across the entire winding. The top of this winding goes to the anode of a diode, the cathode goes to the anode of another diode. There are two 470 k ohm resistors one in parallel with each diode. The bottom of the winding connects to a similar set of diodes and resistors. The cathodes of the second diodes in top and bottom connect together and to the plus end of a 150 u f 450 volt cap. The negative end goes to the positive end of another similar cap. The negative of the second cap goes to ground. There is a 150 k ohm 2 watt resistor in parallel with each cap. The junction of the two diode cathodes and the capacitor goes through a 25 ohm 5 watt resistor to B plus 1. B plus 1 also goes through a 50 u f 500 volt cap to ground. B plus 1 goes through a 9 Henry 120 mA choke to the positive end of another 50 u f 500 volt cap. The negative end is grounded. The positive end of this cap goes through a 2.5 k ohm 5 watt resistor to B plus 2. B plus 2 goes to ground through another 50 u f 500 volt cap. B plus 2 goes through a 2.4 k ohm 3 watt resistor to B plus 3. B plus 3 goes to ground through another 50 u f 500 volt cap. The junction of the 9 Henry choke and 2.5 k ohm resistor goes to the plate of a tetrode. There is a 2 k ohm resistor from the plate to the screen. There is a capacitor of unknown value from the screen to the cathode. The control grid of the tetrode goes through a 2.7 k ohm resistor to the plate of a triode. The plate of the triode goes through a 200 k ohm resistor to the plate of the tetrode. The cathode of the triode goes to the cathode of a zener diode, 100 volt 5 watt. The anode is grounded. The cathode of the triode and zener diode go through a 330 k ohm 3 watt resistor to the plate of the tetrode. There is a 10 u f 500 volt cap from the plate of the tetrode to ground. There is a capacitor, value not legible, from the cathode of the tetrode to the grid of the triode. The tetrode cathode also goes through a 150 k ohm resistor, then a 10 k ohm pot, then a 100 k ohm resistor to ground. The wiper of the pot goes to the grid of the triode. There is a 10 u f 450 volt cap from the tetrode cathode to ground. The tetrode cathode goes to a point labeled 240 volts. The cathode also goes through a 75 k ohm resistor, then a 100 k ohm, then another 75 k ohm to ground. There is a 0.32 u f cap in parallel with the bottom 75 k ohm. The junction of the top 75 k and 100 k is labeled point eh. The junction of the bottom 75 k and 100 k is labeled point B. Going back to the B plus winding on the transformer there are two taps for lower voltage between the center tap and the ends. Each of these taps goes to the cathode of a diode. The two anodes connect together. The two anodes go to the negative end of a 22 u f 250 volt cap, the positive end is grounded. The diode anodes also go through a 100 k ohm resistor to the negative end of another 22 u f 250 volt cap. The positive end is grounded. The negative end of this cap goes to the left ends of two 50 k ohm pots. The right ends connect together and go to ground through a 15 k ohm resistor. The wiper of one pot goes to a point labeled bias R and the other wiper goes to bias L. End verbal description.
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