must you play music to break in tubes
I have some GE 12ax7 longplate tubes that make some loud crackling noises. The Seller claimed that this is common with nos tubes and that it will go away after they are broken in, but it is too alarming to hear and sounds risky to the speakers. Might leaving the amp powered up for a while, but with no signal passing, break them in adequately? Kind of hate wasting the power tubes lifetimes, but I don't have any old tubes to use in that amp.
+1 @glennewdick & @larryi If they are true NOS tubes, crackling is not uncommon. Take each tube out. Give it a decent tap. I give noisy NOS tubes a few hard flicks with my fingernail. Re-install. If the crackling persists after 20 minutes or so, it’s probably a microphonic tube. Return if possible. Yet, some microphonic tubes might be unlistenable in the buffer stage but could be totally quiet in the output stage. Or visa versa. It depends on the circuit design. |
