Figure 17 Long Tail Pair as Implemented by Tim. The hot input terminal goes through a 0.1 u f capacitor to the grid of a triode. The grid also connects to a 100 k ohm resistor. The other end of the resistor connects to a point labeled capitol e small cc. The grid goes to the grid of the second triode through a 910 k ohm resistor. The grid of the second triode goes to ground through a 0.1 u f capacitor. The cathodes of the two triodes are tied together and go through a 10 k ohm resistor to the positive side of a current sink. The negative end of the current sink goes through a 360 ohm resistor to ground. The symbol for the current sink is the two overlapping circles used in schematics of operational amplifier integrated circuits. A line goes to the left side of the symbol indicating a control element. The control element goes through a 1.1 k ohm resistor to ground. The plate of the first triode goes to one end of a resistor. The plate of the second triode goes to one end of another resistor. Both resistors are labeled star 33 k ohms. The other ends of both resistors go to a point labeled capitol e small bb. 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. The star refers to a note on the schematic. It reads as follows. Tim used 27 k ohm resistors and a 10 k ohm pot in the plate circuit. The wiper of the pot connected to capitol E small bb and each end to one end of a 27 k ohm resistor. The other end of each resistor went to the plate of each triode. If the pot wiper was centered that would add 5 k to each plate resistor. Each resistor would then be 32 k ohms. 33 k ohms is close enough. This completes the description of figure 17.
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