Power Supply
- solid state power supply
- use a voltage doubler to double/rectify the transformer output of 72V to about 210V and then use RCLCLC (R=200 ohm, L=5H, C=80u) to smooth the ripples to about 180V (B+).
- current is about 30 mA.
- use 200k and 47K resistors to connect across the B+ and ground to tap out about 40V and connect to the pin 4 and 5 (filament) of 5687 tube.
- use a 6V (6VA) transformer as the supply of the filament of 5687 tube.
FET preamplifier and 5687 amplifier
- refer to Colin circuit
Components
- all components are not expensive one.
Results
- I believe the one I made is very good but may be not as good as the one made by Colin.
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