2. misc-audio
  3. 192535-1853

Western Electric 300B problem

So I recently purchased pair of WE300B, Friday night first listen. At start up heard mechanical pinging and popping, pre muted so nothing through speakers, after the pinging and popping ended, pre out of mute heard nothing unusual through speakers. No issues other than blue glow at tops of tube throughout 5 hour listening session. Tonight I power up tubes for second listen, immediately see left monoblock tube goes completely cloudy with blue fog throughout tube, this along with popping, right monoblock tube fine.

 

So it seems I have gassy tube, lost vacuum already! And here I thought recent improvements with quality control there had solved these issues. Not happy with this purchase, been running Psvane Acme 300B's for nearly 1000 hours with no issues.

sns
sns OP
3,325 posts
 

Transparent blue glow that's generally found at top of tubes is something I often see. This was a sudden flash of extremely opaque or fog like blue that enveloped entire tube, this accompanied by a loud pop through loudspeakers, I wasn't going to wait for further events, amp immediately shut down! This happened perhaps five minutes after firing up both monoblocks, had just taken pre out of mute, very low volume level, didn't hear any noticeable distortion, music playing right up to point of blue flash and pop.

sns OP
3,325 posts
 

Forgot to mention. No white, flaking on getter, I too have seen this with some 101D tube failures. The other thing which I've failed to mention is mechanical noise from failed tube when first picked up, not that this is completely unknown previously, just noted from the beginning,

sns OP
3,325 posts
 

In regards Upscale, just received my Return Authorization. I explained symptoms and sent photo, they agree tube defective.

mwood
60 posts
 

Good news! I hope this completely solves the problem. 

sns OP
3,325 posts
 

Discovered my GZ34 rectifier tube was trashed. So, is this amazing coincidence rectifier tube decides to fail just after replacing 300B tubes or did failing WE take out rectifier tube?

 

Too bad, these early 50's Mullard GZ34, probably around 700 hours on them. Hope I can find some nice replacements. I guess it could be much worse, damage to amp.

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