Tone control power supply. There are two power supply circuits in this diagram. One uses a full wave center tapped rectifier circuit and the other uses a bridge rectifier circuit. They will be described one at a time.

Circuit 1, full wave center tapped rectifier. A standard AC line plug has one prong connected directly to one side of the transformer primary. The other prong connects through a single pole single throw switch then through a one half amp fuse to the other side of the primary. The transformer has a standard 120 or 125 volt primary. Note, change this if you live outside of north America. The transformer has two secondaries. One is the high voltage winding which may be specified in one of two ways. One. One eighty five, dash, zero, dash, one eighty five. After this the catalog or website may say volts or volts AC. There will also be a current specification which may employ the at sign. The current should be a minimum of 25 mA but may be anything higher. Note, higher current will generally cost more money. The other winding is a 6.3 volt winding for the tube heaters and should have a minimum current of 2 amps.

The high voltage secondary has three connections. Two ends and a center tap. One end connects to the anode of a diode, general purpose rectifier 1000 volt 1 amp 1N4007 for example. The other end of the winding connects to the anode of another identical diode.

The cathodes of the two diodes connect together and also connect to the positive side of a forty seven micro farad 350 volt capacitor. The negative side connects to the negative high voltage output. The center tap of the winding also connects to the negative high voltage. From now on called minus H V. The positive end of the forty seven u f capacitor connects to one end of a one k ohm one watt resistor. The other end of this resistor connects to the positive end of a one hundred u f 350 V cap. The negative end goes to minus H V. The positive end of the one hundred u f cap goes to another 1 k ohm 1 watt resistor. The other end of this resistor goes to the positive of another 100 u f 350 V cap. The negative end goes to minus H V. The positive end of this 100 u f cap goes to the positive H V output. A legend between the two output terminals says 250 V nominal at 5 to 10 mA.

The 6.3 volt winding is shown without a center tap. If yours has one connect it to the minus H V terminal and omit the two resistors in the following. Each side of the 6.3 volt winding connects to an output terminal. These two output terminals are labeled 6.3 V A C at 2 amps. If there is no center tap on the 6.3 volt winding of your transformer connect a 100 ohm one half watt resistor from one side of the winding to the minus H V terminal. Similarly connect another 100 ohm one half watt resistor from the other side of the 6.3 volt winding to the minus H V terminal. This completes the description of the first, top diagram.

Between the two diagrams is the text, build one or the other but not both.

Circuit two, bridge rectifier. A standard AC line plug has one prong connected directly to one side of the transformer primary. The other prong connects through a single pole single throw switch then through a one half amp fuse to the other side of the primary. The transformer has a standard 120 or 125 volt primary. Note, change this if you live outside of north America. The transformer has two secondaries. One is the high voltage winding which should be specified as follows. One eighty five volts. or VAC for volts alternating current. There will also be a current specification which may employ the at sign. The current should be a minimum of 25 mA but may be anything higher. Note, higher current will generally cost more money. The other winding is a 6.3 volt winding for the tube heaters and should have a minimum current of 2 amps.

D1, D2, D3, and D4, are 1000 V 1 A diodes, 1N4007 as above. One end of the H V winding connects to the cathode of D 1 and the anode of D 2. The other end of the winding connects to the cathode of D3 and the anode of D4. The anodes of D1 and D3 are connected together and also connect to the minus H V terminal for this power supply. The minus H V terminals of the two circuits are not connected. The cathodes of D2 and D4 are connected together and also connect to the positive side of a forty seven micro farad 350 volt capacitor. The negative side connects to the negative high voltage output. The positive end of the forty seven u f capacitor connects to one end of a one k ohm one watt resistor. The other end of this resistor connects to the positive end of a one hundred u f 350 V cap. The negative end goes to minus H V. The positive end of the one hundred u f cap goes to another 1 k ohm 1 watt resistor. The other end of this resistor goes to the positive of another 100 u f 350 V cap. The negative end goes to minus H V. The positive end of this 100 u f cap goes to the positive H V output. A legend between the two output terminals says 250 V nominal at 5 to 10 mA.