• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

6BQ5 Bias Point Help


2010-02-16 9:00 am
Is there a better way to determine bias point and grid volts for different Vg2 volts besides looking at the Vg2=250V curves and guessing?

Sometimes I have made pure experimetal tests by having all variable voltages (supply-, g2- and -g1-voltage) for a tube under test and also variable load resistance.

Then all required combinations can be tested and the results are fully "live".

I see this as the best way if not suitable data is available.
I have used this method for some soviet-made output tubes with good results.

Ofcourse this requires that one has some test equipment available.