How do you remove a tube Key?



I’ve had this issue before but it was during a DIY tweak to the amps so I could bias them by myself. The amps were both opened up by a friend and it was simple for him to do the fix.

EL 34 tubes have what I call a locator key. The plastic part down by the pins that locates the proper alignment of the tubes into the tube socket. It also covers the point where the glass tube is drawn out, providing protection to that slim glass point amongst the tube’s metal pins.

Thinking to rotate some of my tubes from one amp to the other, the tube came out but the plastic pin/key stayed in the amp. Super.

Consequently another tube couldn’t be interchanged with that spot until the plastic piece is removed.

Is there some way to remove this piece without opening up the amp and pushing it out from behind the tube socket itself?

Also, What about re-afixing the plastic thingy to the tube itself?

Don’t worry about that, or what?

BTW… as this has happened to me at least once before, is this a common thing?

Can it be overcome/avoided somehow, apart from the obvious… don’t mess with it once they are in place bit… ? Or is this just part of using EL 34 based amps?

Mucho gras'
blindjim
I did have one recently and once the amp cooled off I used a small piece of duct tape and stuck it to the pin and it came out very easily...
You apparently have another problem that hasn't been mentioned -- the tube fitting way too tightly (the key part anyway) into the tube socket. When a key has broken off for me, the the broken-off part has come out very easily -- just insert anything pointed and pull it out. If there is any resistance at all I'd think you need one or more new tube sockets. Just for what it's worth. Dave

Thanks much.

Good ideas all.. especially Rod's.

I can't tell really if things got broken off... I suspect the glue just came free between the glass and the plastic cup covering the nipple of the tube.

Likely heat and cooling, etc... and or poor QA. beats me... they're Russian 34's, and were bought new from AES, in AZ.

BTW... FWIW 2, rotating a couple of the tubes from one block to the other, and repositioning the preamps power sup was worth the effort... suprisingly so!

This deal never ceases to amaze me how apparently minor changes can affect such noticeable results.

THX !!