ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

previous: Dave H. q{ So is this crossover distortion ... -- 10/7/1999 4:10 PM

Re: Cathode bias questions

10/7/1999 4:42 PM
peter	Re: Cathode bias questions you're right Dave, it became clear when I re-read your post above. At idle i have a cathode voltage of 32 volts, but with a big signal present that goes up to about 60 volts, so the crossover distortion comes from the fact that the tubes are biased OFF at 60 volts. And you are also right that I can't set the bias current any higher (or smoke will result!). So the solutions are less B+ or change the load (which is easy to try cos it's multi-tapped). thanks, peter

10/7/1999 4:42 PM

peter

Re: Cathode bias questions

you're right Dave, it became clear when I re-read
your post above. At idle i have a cathode voltage
of 32 volts, but with a big signal present
that goes up to about 60 volts, so the
crossover distortion comes from the fact that
the tubes are biased OFF at 60 volts.
And you are also right that I can't set the bias
current any higher (or smoke will result!).
So the solutions are less B+ or change the
load (which is easy to try cos it's multi-tapped).

thanks,

peter