rplace Posted July 5, 2018 Share Posted July 5, 2018 I've got a vintage Sylvania 6SN7 that really rattles when lightly shaken. I can't see anything moving inside it but it sounds like it might be the size of a BB. It powers up and plays fine. If anything maybe, just maybe it burns brighter than the others. Any concerns there? In the couple of cases I've had were tubes got noisy I just replaced them. As a general rule when a tube has a problem is it just like a light bulb burning out? Remove and replace? Is there any case where a "bad" tube can actually damage the equipment? Quote Link to comment Share on other sites More sharing options...
Schu Posted July 6, 2018 Share Posted July 6, 2018 Does it suffer from microphonics? Quote Link to comment Share on other sites More sharing options...
Guest wdecho Posted July 6, 2018 Share Posted July 6, 2018 I would not use it myself. Yes a bad tube can damage other parts especially rectifier tubes. I had one to fail and burned out the transformer when it shorted. Why take a chance? Quote Link to comment Share on other sites More sharing options...
thebes Posted July 6, 2018 Share Posted July 6, 2018 Try twisting the base lightly. Sounds like the glue has dried out on the Bakelite. Can be re-glued, forget which glue is best but a search will tell you. 1 Quote Link to comment Share on other sites More sharing options...
rplace Posted July 6, 2018 Author Share Posted July 6, 2018 13 hours ago, Schu said: Does it suffer from microphonics? No. Also I hear no difference when swapping other tubes. Quote Link to comment Share on other sites More sharing options...
thebes Posted July 6, 2018 Share Posted July 6, 2018 Again it's probably dried glue at the base of the Bakelite, unless it's a metal 6SN7? Quote Link to comment Share on other sites More sharing options...
thebes Posted July 6, 2018 Share Posted July 6, 2018 Here's one of dozens of threads around the web about this subject. I'm including it cause it's talking about loose bases in 6SN7 tubes: http://audiokarma.org/forums/index.php?threads/loose-tube-bases.204663/ 1 Quote Link to comment Share on other sites More sharing options...
rplace Posted July 9, 2018 Author Share Posted July 9, 2018 On 7/6/2018 at 7:25 PM, thebes said: Here's one of dozens of threads around the web about this subject. I'm including it cause it's talking about loose bases in 6SN7 tubes: http://audiokarma.org/forums/index.php?threads/loose-tube-bases.204663/ Marty link does not work for me, but I twisted ever so slightly and BOOM, no noise. I didn't even feel it turn, just sort of applied some twisting pressure between base and glass. Thanks! Quote Link to comment Share on other sites More sharing options...
thebes Posted July 9, 2018 Share Posted July 9, 2018 Acetone or nail polish remover will reactivate the glue. Quote Link to comment Share on other sites More sharing options...
rplace Posted July 9, 2018 Author Share Posted July 9, 2018 Why do I think Vacuum Tube and the word vacuum means no air inside? If the glue is bad isn't the vacuum gone and it no longer a vacuum tube but just a glass tube? Quote Link to comment Share on other sites More sharing options...
thebes Posted July 10, 2018 Share Posted July 10, 2018 When the inside of the glass looks milky white the vacuum is gone. The base actually is attached to the wires coming out of the glass envelope which is where the glass is. The base is like a flower vase, it holds the flowers ,but is not of the flowers. 1 Quote Link to comment Share on other sites More sharing options...
rplace Posted July 10, 2018 Author Share Posted July 10, 2018 15 hours ago, thebes said: When the inside of the glass looks milky white the vacuum is gone. The base actually is attached to the wires coming out of the glass envelope which is where the glass is. The base is like a flower vase, it holds the flowers ,but is not of the flowers. I see, sort of like the old flash bulbs where the wires were bent around the outside of the glass. Glass being "sealed" up but wires out. On the tubes they have the addition of pins and base. I was incorrectly thinking the base sealed the glass. Silly me. Thanks Marty! Ya learn something new everyday....guess I'm done for today. Quote Link to comment Share on other sites More sharing options...
rplace Posted July 10, 2018 Author Share Posted July 10, 2018 Funny hobby we have. Postman (lady actually), er mail carrier just had me sign for two Ken-Rad 6SN7 tubes. Made in USA, but they came by way of Holland. Wonder what the carbon footprint of my tubes are? 1 Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted September 9, 2018 Share Posted September 9, 2018 Rich, let me know if you need a couple 6sn7gtb. Quote Link to comment Share on other sites More sharing options...
OO1 Posted September 10, 2018 Share Posted September 10, 2018 - Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted September 10, 2018 Share Posted September 10, 2018 On 7/10/2018 at 1:37 PM, rplace said: Funny hobby we have. Postman (lady actually), er mail carrier just had me sign for two Ken-Rad 6SN7 tubes. Made in USA, but they came by way of Holland. Wonder what the carbon footprint of my tubes are? Good move! Quote Link to comment Share on other sites More sharing options...
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