Tube Contact Issues

[Designsfx]

Hello All-
I wanted to see if anyone here has any hands on experience/expertise in dealing with worn/age contacts like those shown on the tube pictured (Tungsram EL5).



I realize these contacts are troublesome in general with issues ranging from persistent crackling and hum to extremes of intermittent operation. Some suggest the best method of approach is to just leave it in the adapter (once you get it working) but even that has proven to be a challenge with issues of hum returning out of the blue.
I have a few of these tubes and every one has demonstrated this issue at one point or another. I can’t blame this on the tube base as they seem to be in order.
Has anyone ever attempted or made a successful repair to this type of tube? Any suggestions would be greatly appreciated.

 

[CDawg]

@oldvinyl gave out some incredible information on cleaning tube pins for lowering noise that might be able to help you.

My Tube Collection, Welcome to share yours

That looks similar to 6SN7 or 6SL7 or 12SN7 internal construction. T plates at the top.

www.whatsbestforum.com

I tried cleaning tube pins using a toothbrush and rubbing alcohol and documented the changes in noise on a Maxipreamp II tube tester. That's about 10 minutes of soaking with rubbing alcohol and a few scrubs with a tooth brush. I know what was suggested would be even better.

 

[Designsfx]

@oldvinyl gave out some incredible information on cleaning tube pins for lowering noise that might be able to help you.

My Tube Collection, Welcome to share yours

That looks similar to 6SN7 or 6SL7 or 12SN7 internal construction. T plates at the top.

www.whatsbestforum.com

I tried cleaning tube pins using a toothbrush and rubbing alcohol and documented the changes in noise on a Maxipreamp II tube tester. That's about 10 minutes of soaking with rubbing alcohol and a few scrubs with a tooth brush. I know what was suggested would be even better.

Thanks for the response! I’ll give this a read. I’m actually wondering if anyone has knowledge of reconditioning the shape of the contacts themselves, or if better suited, re-forming them. I’ve heard of some adding solder to the contacts to improve surface area but wonder if there is a method of improving the contact via some form of replacement.

 

[oldvinyl]

You might be able to touch up the contacts by resoldering them. Extreme care is needed to only heat the contacts and not melt the base or up into the tube. There are heat sinks to attach to keep the hear just at the tip.

Cleaning the contacts AND the sockets is highly recommended. The results can be quite amazing.