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Nobsound 6P1 HiFi Valve Amplifier Fixing the Power Supply, Resistor in series with Tube Rectifier.



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- WARNING HIGH VOLTAGES CAN KILL YOU, IF IN DOUBT USE AN EXPERT -
-- ALL SHOWN IN THIS VIDEO IS DONE AT YOUR OWN RISK --

My Nobsound 6P1 has a transformer labeled 240 volts inside, so you would have thought this would be just right for the 240 volts from my mains supply.
But it was not the case, even though the 5 volt and 6.3 volt heater AC voltages were correct, the voltage going to the Anodes of the 6P1's was 276 volts DC which is 26 volts over the maximum recommended.

I could have used either a Auto Transformer or Voltage Regulator to decrease the input voltage to the amp from 240 volts to say 225 volts, but this decreased the heater voltages as well to 5.7 volts AC

So I have put a resistor in series with the Tube Rectifier to decrease the voltage to pretty much were they should be.

This is the U.K version I have modified, power consumption was 90 watts before and 82 watts after mod.

For full details on changing power supply capacitor and installing blead resistor info below
Skunkie Design Electronics Power Supply Video can be found here
https://www.youtube.com/watch?v=5WYV5wng29U&t=869s
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Audio
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