Strange tube buzz?

Tubes Asylum

Questions about tubes and gear that glows. FAQ

I tried a pair of vintage 5963 tubes in my ForplayIII pre-amp today. I usually use 12au7a/5814a. with no problems. With 5963 a strange buzzing sound occured mixed with the music.
Even more strange, with the power amp off a buzzing tone eminated from the preamp,that is, the tube itself. This was even without any signal to the preamp. A recording anlysis showed that the tube gives off a 400 hz tone and alot of grungy noise in the 8khz-15-khz area.
Luckily I got the tubes cheap, but I am more puzzled how and why a tube can produce audible noise into the room with no signal and no loudspeakers on!!
Any explanations are welcome
Best regard
Balle Clorin

This post is made possible by the generous support of people like you and our sponsors:

Parts Connexion

Topic - Strange tube buzz? - Balle Clorin 11:27:14 06/06/06 (0)

You can not post to an archived thread.