Changing valves

[bigthumb73]

My Pro-TubeIX needs new valves. Has anybody changed them themself and
if so are there any problems or issues I need to know about? Dose anybody
recommend specific makes as well? Your tips/recommendations will be greatly received coz i dont have a clue!

 

[naetog]

I've heard you shouldn't touch the tubes when installing new ones since the oils on your hand can do some sort of harm, so I put on my batting glove to replace. I used some Groove Tubes on mine and they sound great. I know one is a 12ax7, but I can't remember the other.

 

[Gareth_Flatlands]

I've heard you shouldn't touch the tubes when installing new ones since the oils on your hand can do some sort of harm

It's to do with difference in heat conduction causing cracks n the glass when the tubes get hot. Same with car headlight bulbs. Use a clean cloth or similar when handling tubes. Unless they're already gone.

 

[bigthumb73]

Can I take it that you just remove the old ones and fit the new ones and thats that. No biasing etc...?

 

[Florin]

Yes Just replace with similar tubes. Try different brands, and see wich one sounds better for you

 

[Sebastiano Rizzo]

Hi guys!
I'm new here and I'm writing because last saturday I bought an ex-demo Pro Tube IX and one JJ EL34. Yesterday I tried to change the tube, but..surprise! The 2nd stage tube, the EL34, is smaller the the JJ I've bought! Where can I find "small" tubes? Because I've seen only the "normal-big" ones..
Thanks,
Sebastiano

 

[rusty]

Double check the JJ tube, i thought the protube has a EL84 and 12ax7's in it. Not a EL34.

 

[Sebastiano Rizzo]

Yesterday morning I controlled better: you're right, it's a EL84. I don't know why I was sure it was an EL34..