EL34

[cobretti]

I have just got brand new JJ EL34 matched pair for my Marshall 50W (clone) and since I am a solid state guy and have no experience with tubes I would like to ask here. When 6.3VAC is applied to heaters, one of the tube rattles like a rattlesnake. Does it mean there is something loose inside the tube and hence the mechanical noise? Should I get a new pair or live with it?

 

[rayma]

When 6.3VAC is applied to heaters, one of the tube rattles like a rattlesnake.
Should I get a new pair or live with it?

They may work ok, but I still would ask to exchange them for another pair.
This is not normal.

 

[Enzo]

Nothing should rattle in a tube. HAve them replace the tubes.

 

[DF96]

EL34 can sometimes click a bit as they heat up or cool down, but should be silent during normal use.

 

[samhill]

I have on occasion found a little chip of glass rattling around inside. Don't recall if it was pulls, NOS, or new that I could return but I just let those be figuring no big deal. If new you should return them just to force quality control higher.

 

[cobretti]

OK, thanks. Good to know. I sent them for replacement. Meanwhile I ordered another pair of EL34, Mullard this time. They feel and look more solid to me. Dead quiet and seem more rugged. I was also looking on different tube manufacturers like Svetlana or Tung Sol but they have a little different internal construction. I don't like that top and bottom isolating spacer. The whole construction seems to float in the space, unlike the Mullard has both spacers leaning on the glass and holding it nicely in position.