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Hello all,
I really hope you guys can help me out. Just bought a new pair of the Western Electric 300B new production from an authorized dealer in Southern California (I actually had to go through 3 pairs to pick out the best pair..the first pair got really loose pins, the 2nd pair had a crack on one of the tube's base).Here's the problem: I had this pair for about 2 weeks now, about 110-130hrs on them. At first, the tubes displayed a blue glow in the dome of the envelops, which, according to WE's website FAQ, is normal. Now, the blue glow extends down to the base of the tubes and it moves in a sweeping motion like a light show. When the light moves, i can hear a soft hissing sound and also a soft pop/click as well (when the glow starts moving and stops moving)
Has anyone had this experience with WE300B tubes before? Will this phenomenon go away after the tubes burn in more or this is a sign of defects? Is this SAFE to use or should i unplug them???
Follow Ups:
Jaytea, hi. Sounds like classic gassy tube syndrome. Normal blue glow hugs the inner glass surface. Three dimensional glowing as you describe moving in a sweeping motion in the interior is as far from normal as you can get. Don't run these tubes. Return them as defective. How tube savvy is your dealer? What you have been observing is a severe warning sign. The next thing that will happen is the ionization of gas on the interior will continue to the point where thermal runaway can take place and lead to catastrophic failure of the tube. This could take out an output transformer. In what amp are your WE 300B?
Hi Elektron,
Thanx so much for the response,
I'm using that pair in the Manley Neo-classic 300B preamp, which runs these tubes very conservatively. My stock tubes are Electro Harmonix are fine..but the sound of the 300B are more balanced...except now they pop and click (even still softly). So i made a smart move by stop using them? According to what you said..it sounds really bad..i should talk to my dealer today. I tried to email WE, but seems like they dont have customer support hotline/email.
JayTea, hi. Communicate with your tube vendor about the 300B. Yes, you made a smart move by not using them. What warranty information came with your WE purchase? Does the vendor serve as the nexus for warranty claims? Glad your EH are fine. I was going to suggest checking out the JJ Electronics (Slovak Republic) 300B. Antique Electronic Supply has them at a good price. I bought my first pair of these a couple of years ago. The tubes proved to be well made, were super stable holding bias, and sounded terrific. To date I have had zero problems with the JJ 300B. The Manley sounds like a very nice machine. I can't imagine the tubes get stressed too much in it. You might inform Manley what is happening just to cover the bases. Best wishes on resolving the issue.
Hi Elektron,
My WE came with the 1 year warranty (provided the warranty cards returned within 10days of purchase, well i did...otherwise, the warranty 'd be 90 days, i think). I'm working with the dealer on this problem...awaiting his response now. Manley said they use the 300B in the preamp very conservatively..so i dont think that's the reason why the tubes were stressed. I'll keep you posted.
Thanx
JayTea, hello again. Sounds to me you have covered the necessary bases. Once upon a time when the Bell System depended on tubes manufactured by Western Electric (supply arm of Bell) tubes would have gone into burn in racks to cull clinkers. WE had some pretty stringent performance rules for QC when the plant at Lee's Summit MO was in its hayday. See books by Bernie Majors on WE. It would have been unthinkable a bad tube would leave the factory. On average 20,000 hours of service was entirely possible. It is a different world now, it would seem.
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