I did a bad thing, I think...

[Vault 35]

I made the mistake of dusting my tubes when they were hot. I forgot that I had connected the integ amp to the power conditioner in the "on" position for switch on. Now there are filaments of Swiffer baked on to the backs of the EL34 tubes of my PrimaLuna Prologue One. This is only visible if I look at the back of the tubes with a flashlight. In addition to this, I have noticed that the tubes have a ring of brown stain around the top. I am pretty sure this is because I smoke cigarettes in my listenting room. The amp works just fine so far but I worry about it because this is my first tube component...

Is there a safe way of cleaning these tubes periodically, or is it even necessary?

 

[JoeE SP9]

That stuff stuck on them can cause hot spots. On power tubes this can be very bad. Let them cool down completely. Remove them and very gently scrape of the grunge with a razor blade. The brown rings if they are from smoking should come off with a little rubbing alcohol. Treat them gently and after cleaning reinsert them in the same sockets you removed them from. This would be a good time to use Cramolin, Caig or some other contact enhancer on the tube pins and sockets. Doing the same to all your other connections wouldn't hurt. Re-set the bias after a suitable warm up and "Bob's your uncle" as they say down under.

 

[mtrycrafts]

I made the mistake of dusting my tubes when they were hot. I forgot that I had connected the integ amp to the power conditioner in the "on" position for switch on. Now there are filaments of Swiffer baked on to the backs of the EL34 tubes of my PrimaLuna Prologue One. This is only visible if I look at the back of the tubes with a flashlight. In addition to this, I have noticed that the tubes have a ring of brown stain around the top. I am pretty sure this is because I smoke cigarettes in my listenting room. The amp works just fine so far but I worry about it because this is my first tube component...

Is there a safe way of cleaning these tubes periodically, or is it even necessary?

Yes, that is a bad event
Not sure how much damage you caused right now, but I bet it will shorten the life a lot, if they still operate.

Next time clean them when they are off, cold. And wait for any moisture to dry.
Almost the same as when you use a wet cloth on an incandescent bulb, goes pow.

 

[highfihoney]

keeping dust from baking on your tubes will increase tube life,unless your running some seriously expensive tubes like genelex or telefunkens where the lettering is essential to their value you should be able to use any cleaner you like that works on glass.

As for the burnt on swiffer chunks i would think the razor blade suggestion is as good as any i can think of.

 

[Vault 35]

Thanks for the suggestions. I tried the combination razor blade / alcohol solution. The melted filaments were very difficult to see even when I got the tubes out and looked at them in front of the light. The razor did remove a fair amount of crud, however, from the EL34s. The little 12s were pristine. Anyway, I got them all back in and powered up and everythings sounds fine.