Hola Bueno acá les posteo algo que encontre y que me parecio muuuuuy interesante!..... espero que comenten y aporten si les interesa el tema, yo recien me estoy interiorizando en el tema diy y de audio valvular, ó lo que seria " Electronica Vieja ", bueno un saludo a todos!
Antes que nada les pongo acá el link sobre un folleto de datos de válvulas y semiconductores de Germanio (Folleto Antiguo MiniWatt), me parecio buena ideo incluirlo para el que quiera empezar o para que lo tengan,
Bueno vamos al grano!
EL 84/6BQ5 Tube Amplifier
EL84 6BQ5 Universal PCB
When experimenting with tube amplifiers, you might be confused about the different modes of operation, like triode or pentode mode. To give a little guidance i developed this PCB. You can build small Amplifiers based on 6P14/6BQ5/EL84 easily, and the output Power of 2..6 Watts is more than enough for home use.
With this PCB you can try out the different Modes by means of Jumper Wires.
The Schematic is very simple:
This PCB is of course only one part of an Amplifier, you will need at least a Power Supply and output Transformers.
The PSU has to supply the filament Voltage and the Plate Voltage of about 250V
Filament voltage is connected to X2, Plate Voltage is connected to X3 and the output transformer is connected to X4
A Pentode like the EL84 can be operated in 3 different Modes:
Ultralinear
Triode
Pentode
Each of the 3 Modes has its unique sound characteristics, just try them and find out which one you like best!
An Overview how to connect the different modes
Component Values
R1 Cathode Resistor, see table above
R2 1kOhm
R3 1MOhm
R4 100Ohm/1W
C1 470uF/35V
Selecting a Tube:
All EL84 Types can be used, such as 6P14 or 6BQ5. The circuit was tested with EL84.
Bestückungshinweise:
The Cathode Resistors and the screen Grid Resistor should be rated for 1W, as the can get quite warm during operation.
The tube gets very hot during operation, so ensure proper venting!
An EL84 type tube needs several volts for full output power. Usage of a preamp is therefore recommended. A CD Player with headphone-out is a good start and usually enough to drive the Tube. the output needs to be DC-Free, so decoupling with a suitable capacitor might be neccessary.
Never connect a signal source with a DC Component to the circuit, this could lead to damage of the Tube and output transformer
Always ensure that a proper load is connected to the output transformer! Tube Amplifiers usually dont like being operated without load!
Here a picture of a complete AMP, consisting of PSU, power transformer, output Transformer and EL84 PCB
Acá pueden obtener la fuente de poder estabilizada con MOSFET para alimentar hasta 2 módulos amplificadores de estos:
Mosfet stabilized High Voltage Power Supply
Bueno espero les sirva y como dije; Aporten y Comenten sobre el Tema! Saludos a todos!!!!
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