Adhesive/bond for horizontal preamp tube

[glebert]

Working on a Carvin R600 with 12AX7 preamp tube mounted horizontal with no retainer. I think the existing tube was the original, and it looks like it had a drop of adhesive or bond from the base to the tube itself. Is this recommended to do when replacing tubes, and if so what type of bonding material? I found another thread that mentioned RTV, and I have some red high temp gasket making material, wondered if a drop of that would work.

Thanks,
Greg

[Enzo]

It may not be needed. Plug a tube in and see if it comes loose. You can always goop it later.

It is REAL important that your goo be non-conductive. Your gasket goo may or may not meet that standard.

A dab of plain old silicone would work.

[glebert]

I know getting the old tube out was a PITA. Makes me worry about the PCB mount socket solder joints.

[olddawg]

You can't figure out a way to incoperate a standard retainer wire? Or.. if there's room and you are worried about the socket anyway.. replace it with a $3 ceramic socket with a retainer wire or a twist on shield?

[glebert]

Doing this a a "minimum cost" job for a regular customer so no redesign, hopefully not even pulling the board from the chassis. Cleaning the master volume pot fixed most of the problem (low, distorted output) but then found out the tube was misbehaving as well.

[olddawg]

Check out a tiny dab of high temp epoxy. But put it in a spot where you can file/chip it out later.

[drewl]

One of the models has retainers for all the preamp tubes except the phase inverter.

A friend had one, and it would always get loose no matter what I tried so I added a retainer.

[glebert]

New tube definitely seems like it would wiggle free after a while, and I know this guy tours locally with a TON of equipment, so I doubt things get treated very well. Will probably try a small drop of silicone adhesive.