Figure 9. Power Supply for all Three Preamplifiers. Shown on the left is a 3 prong AC power plug. The ground prong connects to the metal chassis of the power supply. The neutral wire connects to the bottom of the transformer primary. The hot wire connects through a switch then a fuse to the top of the primary. The secondary is center tapped and there is a capacitor connected across the entire secondary. The capacitor is labeled 5 nf (0.005 u f) 3 kV. Each end of the secondary connects to the anode of a diode. The two cathodes are connected together. The diodes are labeled 1N4007. There is a 100 u f 450 volt capacitor connected from the diode cathodes to the transformer center tap. The junction of the capacitor and two diodes connects to the CCW end of a 10 k 1 watt pot. The other end goes through a 1.5 k ohm resistor to the positive end of another 100 u f 450 volt capacitor. The wiper of the pot is connected to its CW end. The pot is also labeled audio taper. The negative of the second capacitor connects to the center tap. The positive of this capacitor connects to the CCW end of another 10 k ohm audio taper pot. The CW end goes through another 1.5 k ohm resistor to the positive end of a third 100 u f 450 volt capacitor. The negative end goes to the center tap. Like the first one, the wiper of the second pot is connected to its CW end. The positive end of the third capacitor goes to an arrow labeled B plus. The negative end of the third capacitor goes to an arrow labeled B minus. A note just below the lline where all the capacitors connect reads not to chassis. Near the bottom of the figure is a figure that contains the text brick power supply, 12 volt 2 amp, regulated. Lines from the left end of the rectangle go to gthe neutral power line and to the junction of the switch and fuse. Lines from the right hand end go to arrows with the label heaters. This could be either a wall wart or a brick. Or, you could roll your own 12 volt 2 amp power supply in the conventional way.
End verbal description.