Figure 21 Schematic of Complete Amplifier & Long Tail Pair. The hot input terminal goes to the grid of a triode, one half 12 eh Y 7. The grid also goes through a 1 meg ohm resistor to ground. The cathode goes through a 1 k ohm pot connected as a rheostat then a 220 ohm resistor to ground. A note next to the rheostat says adjust for 125 V D C at T P 1. There is a 470 u f 25 volt capacitor in parallel with the rheostat. At the junction of the rheostat and 220 ohm is a connection point labeled g n f b. The plate goes through a 100 k ohm resistor to the source of an I r f 820 m o s f e t. The drain goes to plus 400 volts. The 400 volt line also goes through an 18 k ohm 1 watt then another 18 k ohm 1 watt resistor to the cathode of a 100 volt 5 watt zener diode. The anode goes to the cathode of another 100 volt 5 watt zener and the anode of this zener goes to the cathode of yet another 100 volt 5 watt zener. The anode of the last zener diode goes to ground. There is a 22 u f 450 volt capacitor in parallel with all three zeners. The junction where the cathode of the top zener, the plus side of the 22 u f capacitor, and the 18 k ohm resistor all come together goes through a 1.5 meg ohm then a 150 ohm resistor to the gate of the Mosfet. A 0.047 u f capacitor connects from the junction of the two resistors to the plate of the tube. The plate also connects through a 1 k ohm resistor to the grid, pin 2, of one half 6 C G 7 triode. The grid goes to the grid of the second 6 C G 7 triode, pin 7, through a 1 meg ohm resistor. The grid of the second triode goes to ground through a 0.1 u f capacitor. The cathodes of the two triodes, pins 3 and 8, are tied together and go through a 6.8 k ohm resistor to the drain of an m o s f e t which is labeled IXCP10M45S. The source of the m o s f e t goes through a 330 ohm resistor to ground. The gate goes through a 1 k ohm resistor to ground. The two cathodes also connect to a point called T P 1. The plate of the first 6 C G 7 triode goes to one end of a resistor. The plate of the second 6 C G 7 triode goes to one end of another resistor. Both resistors are labeled 33 k ohms. The other ends of both resistors go to a point we will call B plus 2. The plate of the first triode goes through a 0.1 u f capacitor to output 1. The plate of the second triode goes through a 0.1 u f capacitor to output 2. There are 100 k ohm resistors connected from each output to ground. There is a 2.2 k ohm resistor connected from plus 400 volts to B plus 2. B plus 2 is bypassed to ground by a 47 u f 450 volt capacitor. This completes the description of figure 21.
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