| You should have a good understanding of classes of operation before using this bias calculator. For instance, it is accepted practice to bias a tube operating class AB to 70% of its maximum allowable plate dissipation at idle. For class A, it is 90%. Many amplifiers running a push pull output advertise as being Class A. They aren't. If you are uncertain, you should consult an amp tech or someone on this Tubes Bulletin Board. When setting the bias, all tubes should be installed and the amp should be warmed to normal operating temperature. |