Lighthouse Electric Vacuum Tube Project
Two power supply topologies are shown below. Separate transformers for plate and filament supply are common. Some exaples are shown below. The voltage and current specification depends again on your power tube requirements. Push-pull operation has also the benefit of hum cancellation. Any A-C hum voltage from the power supply will produce currents in opposite directions in the OT primary winding, effectively canceling out each other. However, this advantage applies only to the output stage. Hum introduced in preceeding stages must be filtered out with capacitor-resistor filters or chokes. Center tapped filament circuit uses anti-phase wiring for the gain stages where the center tap of the secondary wiring is grounded. The benefit of this method is reduced 60Hz hum.
Fig.1 Guitar Amp Circuit
Fig.2 Full Wave Power Supply with center tapped transformer.
Fig.3 Full Wave Power Supply with diode bridge.
Fig.4 Center-Tap Filament Supply.
|WARNING Potentially lethal voltages can be present. Do not touch any part of the device with bare hands while under power. After disconnecting power, wait until filter capacitors are discharged. Measure voltage with voltmeter to be sure. If you do not know how to handle high voltage circuits, do not build this device. Get help from a qualified technician.|
Contstruction is similar to the 17W No Frills Guitar Amp. Use that maual for guidance.
|AMPLIFIER PARTS SUPPLIERS|
|REF. #||DESCRIPTION||QUANTITY||PART No:||SUPPLIER|
|NA||Steel chassis Hammond||1||generic||http://www.tubesandmore.com|
|OT1, TR1||Push-Pull Output & Power Transformers||1||generic||http://www.musicalpowersupplies.com|
|OT1||Output Transformer 6L6 25W P-P||1||P-TF41318||http://www.tubesandmore.com|
|NA||Tube sockets, Phono Jacks, Hardware||NA||generic||http://www.tubesandmore.com|
|V1, V2, V3, V4||Power Tubes & Triodes||NA||generic||http://www.tubesandmore.com|
|V1, V2, V3, V4||Power Tubes & Triodes||NA||generic||http://thetubestore.com|
|NA||Passive Componets, Connectors||NA||generic||www.mouser.com, www.jameco.com|
| DISCLAIMER OF LIABILITY:|
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