The biasing is usually set as a maximum of 80% of maximum rated power and 80% of 30 watts is 24 watts. Let’s see how not to get cheesed off with us ! Then you can come another set from this website 🙂, but later be cheesed off as the new set lasted 5 months and you will think I sell rubbish 6L6’s. Above 30 watts, you will cause them to start glowing dull red ( “red plating”) and they will be cooked to death. Most manufacturers state the maximum power the valve can dissipate is 30 watts. The same process is true for E元4‘s, KT66, KT77, KT88, but the numbers will be different according to the maximum power the valve can handle In this example, I will use the figures for the popular 6L6GC as found in Mesa Boogie, Peavey, Fender etc etc etc. Also this affects the amount of power they use. This is to allow the valve to operate in the straight part of the amplification characteristic so that they produce a nice clean sound. A bit like a car engine needs a certain amount of fuel to run when the car is just sitting.

Output valves need to have a certain amount of current flowing through them even when sitting doing nothing. This is a challenge as my wife tells me that I can make a cheese sandwich sound complicated !

I am attempting to write this so as the musicians can understand and so the idea is that I make it hopefully simple to understand.

There is talk of setting the bias “cool” or “hot” and the effects on output valve life. This is also related to the matching of the valves. There is a lot of discussion on the black magic of setting the bias on the output valves in your amp.

Bias guitar amp