Tube Amp Archive

bal704 wrote: ↑Thu Jul 25, 2019 1:42 am Here's a site I use....

http://www.tedweber.com/webervst/tubes1/calcbias.htm

Thank you.

The plate dissipation (Pmax), which is measured in Watts, is the critical variable. Do not exceed the tube's maximum rated dissipation. Consult the relevant data sheet. (Pmax = 42W for a KT88) Plate dissipation (Pmax) = plate voltage (Vp) x plate current (Ip). (You have one measurement (Ip). Now yo...

Gear Breaker! A descriptive handle! Check out this nice bias calculator: https://www.amplifiedparts.com/tech-articles/tube-amplifier-bias-calculator You have to know your plate voltage (fixed bias), or the difference between the plate and cathode voltages (for cathode bias). For 400v plates and KT8...

Hi, Newbie here. I just biased a pair of KT88s and set them to idle at 120ma cathode current. The plates began to look a little cherry. I thought that the cathode current of the KT88 was 230 and I was well below the rated cathode current. I can run EL34s in the same amp and the tubes wont start to g...