What to do if the transformer delivers a higher heater voltage as required? Use a resistor to reduce the voltage you need. In fact you create a voltage divider... The dropping resistor is the first and the Tube - Heater the second resistor of this divider. ![]() |
Tube | Vh (Volts) | Ih (Ampere) |
EL34 / 6CA7 | 6.3 | 1.5 |
EL84 / 6BQ5 | 6.3 | 0.76 |
KT66 | 6.3 | 1.27 |
KT77 | 6.3 | 1.4 |
KT88 / 6550 | 6.3 | 1.6 |
211 | 10.0 | 3.25 |
2A3 | 2.5 | 2.5 |
300B | 5.0 | 1.2 |
5998 | 6.3 | 2.4 |
6AS7 | 6.3 | 2.5 |
6HB5 | 6.3 | 1.5 |
6L6 | 6.3 | 0.9 |
6V6 | 6.3 | 0.45 |
7027 | 6.3 | 0.9 |
7189 | 6.3 | 0.76 |
7558 | 6.3 | 0.8 |
7591 | 6.3 | 0.8 |
801 | 7.5 | 1.25 |
805 | 10.0 | 3.25 |
807 | 6.3 | 0.9 |
811A | 6.3 | 4.0 |
845 | 10.0 | 3.25 |