• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Standard conditions for max plate dissipation vs plate loads

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
Z

zintolo

Member
Joined 2012
cerrem said:
Just a few observation to keep in mind... Idle plate dissipation may be really hot in some amps, however, when running signal the plate dissipation can be much lower...
Click to expand...
Thanks cerrem,

I know better musical instrument that hi-fi amps, and indeed EL84s are the most abused usually (higher plate and screen voltages, higher idle power, etc...). This is not my case, as I usually stay around 60 to 70% idle current for AB fixed bias, and 80 t 90% for cathode biased "class A".


cerrem said:
operating voltages are totally different than idle...therefore the average plate dissipation will be much lower than idel..also taking into account the load-line path...is not linear ...elliptical ..
Click to expand...
Totally agree, maximum plate dissipation is not at idle nor at full power, as it is expected by the intersection of the load-(quasi)line and the "W = V x I = const" ellipse. On top of that, guitar amps often intersecs twice the maximum plate dissipation, just because the avarage is within specs (almost half of the time the tube is off).
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom