Figure 5 The Wise Version of a Bootstrapped Amplifier. The hot input terminal goes through a 0.1 u f capacitor to pin 2, the grid of a triode which is one half of a 6DJ8 dual triode. The cathode, pin 3, goes to the top of a 5 k pot. The wiper is tied to the bottom and they go through a resistor to ground. The resistor is labeled capitol r, small k, and a value of 100 ohms is given. The top of the pot also goes to the positive end of a 470 u f 25 V capacitor. The negative end goes to the junction of the lower end of the pot and the resistor. The grid also goes through a 1 meg ohm resistor to the junction of the pot and resistor in the cathode. This junction also goes to a point labeled g n f b which stands for global negative feedback. The plate, pin 1, goes through a 100 k ohm resistor then another 100 k ohm resistor to plus 400 volts. The plate of the first triode also goes directly to the grid, pin 7, of the second triode one half 6DJ8. The cathode, pin 8, of this triode goes through a 47 k ohm 1 watt resistor to ground. The cathode also goes through a 1 u f capacitor to the junction of the two 100 k ohm resistors in the plate of the first triode. The plate, pin 6, goes through another 47 k ohm 1 watt resistor to plus 400 volts. The plate also goes through a 1 u f capacitor then a 120 k ohm resistor to plus 400 volts. The plate also goes through a 0.1 u f capacitor to output 1. The cathode goes through another 0.1 u f capacitor to output 2. Output 1 goes through a 100 k ohm resistor to ground. Output 2 goes through another 100 k ohm resistor to ground.
Go Back