Feedback with a long tail pair. There are no component values on this diagram. The input connects to the grid of the top triode. There is a resistor from the grid to ground. The cathode connects to the cathode of the bottom triode and both cathodes connect through a resistor to minus 300 volts. The plate of the top triode connects through a resistor to plus 250 volts. The plate also connects through a capacitor to the grid of the top power pentode. This grid connects through a resistor to ground. The grid of the bottom triode connects through a resistor to ground. We will return to this grid later. The cathode has been described above. The plate of the bottom triode connects through a resistor to plus 250 volts. The plate also connects through a capacitor to the grid of the bottom pentode. This grid goes through a resistor to ground. The two cathodes of the pentodes connect together and through a resistor to ground. The screen grids of both pentodes connect to plus 300 volts. The suppressor grid of each pentode is internally connected to its cathode. The plate of the top pentode connects to the top end of the output transformer primary. This point is marked with a dot. The plate of the bottom pentode connects to the bottom end of the primary. The center-tap of the primary connects to plus 300 volts. The bottom end of the secondary is grounded and connects to the bottom speaker output. The top of the secondary is marked with a dot and connects to the top speaker output. The top of the secondary also connects through a resistor to the grid of the bottom triode. End verbal description.
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