The power supply section. The white wire from a 3 wire line cord or the wide prong of a 2 wire cord goes to the bottom of the primary of the power transformer. The black wire from a 3 or the narrow prong of a 2 goes through a 1 amp fuse then the on/off switch to the top of the primary. The green wire from a 3 wire cord goes to the chassis. The high voltage secondary is labeled 300 VCT at 125 mA. The center tap goes to common which is NOT the chassis. Each end of the winding goes to one plate of the 6AX5. The heater of the tube goes to the 6.3 volt winding on the transformer. The cathode goes to the positive end of a 40 mike 250 volt cap, the negative side goes to common. The positive side goes to one end of a filter choke which is labeled 2 to 10 henrys at 125 mA. The other end of the choke goes to the positive end of another 40 mike 250 v cap. The negative end goes to common. There is a 22 k ohm 2 watt res in parallel with this cap. The positive end of the cap goes to the positive DC output terminal and the negative DC output terminal connects to circuit common. The DC output terminals are labeled 200 volts no load, 160 volts at 75 mA. The 6.3 volt winding of the transformer goes to the two output terminals labeled 6.3 V A C. Each side of the 6.3 volt winding goes through a 100 ohm resistor to common. The audio amplifier section. The lower input terminal connects to circuit common. The upper input terminal connects through a .01 mike cap to the grid of the power amplifier tube, 6AQ5 or 6V6. The grid also goes to common through a 470 k ohm res. The cathode goes to common through a 150 ohm res in parallel with a 20 mike 25 volt cap. The plate of the tube goes to the blue wire, primary, of the output transformer, 5000 ohm to voice coil. The red wire, other side of the primary goes to the screen grid of the tube. The suppressor grid is internally connected to the cathode. The screen grid also connects to the positive DC output terminal. Each wire of the secondary of the output transformer goes to one side of the speaker. One side of the speaker is connected to chassis ground. The heater of the tube goes to the 6.3 volt winding of the power transformer. End of verbal description.
go back.