Regolazione del Bias delle Valvole Finali di Potenza (quando è possibile)

Adjustment of the Bias of the Final Power Tubes (when possible or if we have an amplifier with control grid bias with separate power supply and calibration trimmer). The calibration steps are the following: 1) Change the valves (in case of replacement due to exhaustion of the cathode) 2) Connect the multimeter to the cathodic resistance (there is one for each power amplifier tube) 3) Turn the trimmers full scale (usually counterclockwise) for the lowest bias 4) Turn on the unit and check the bias 5) Wait at least 30 minutes 6) Calibrate the bias at 10% lower than the nominal one 7) If we don't have time to wait 10 hours, the calibration ends here. Generally increasing the emission the bias increases by 10% in the following 10 hours. 8) After 10 hours of operation re-calibrate the bias for the nominal value