Western Electric 300B problem

@SNS Sorry to hear of your bad luck and you have my sympathy. I’m sure most people on this forum have experienced this kind of frustration and disappointment and it’s not fun at all.

   I have 4 WE 300B’s that I bought from Upscale. They have been flawless. They were noisy the first time I fired them up and they did emit a slight odor. That scared me. After that it has been smooth sailing and I like them. However, my amps came with Shuguang’s top of the line 300B’s. Just to see if I could tell a difference I re-installed them last Spring. To my great surprise I liked them better. This is not a dig at WE, those tubes are wonderful but I’m slightly happier with the Shuguangs.

Upscale states on their website and with a sheet I received with tubes, "Every power tube is burned in for 72 hours before matching",  I believe this based on my initial listening session. Having forgot this I was extremely surprised on 'mature' presentation, having much experience with tube burn in via exclusive use of tube pre's and amps since 2000 these didn't present as fresh out of the box tubes. Wonderful mids, pretty extended on top, open, transparent, these are not attributes I generally find with new tubes. I was extrapolating a fully burned in presentation as I listened,  something I never do with fresh power tubes, in other words I found these something near final presentation. On one hand I understand finding offense with this as tubes have limited life spans. On the other hand, this is good thing, should assure better matching and less early tube failures/returns from end users.

@mwood The fact you also experienced the odor is somewhat reassuring. I've never smelled this odor prior with these amps, hard to describe the smell.

Audio Research burns in for 48 hours and does extensive testing before shipping or selling. 

Blue glow = good thing, in fact sign of a good vacuum of a power tube. I have several NOS 6L6 and 6550 that have a beautiful blue glow. However, never seen blue glow with any of my new production 300b, Gold Lion, LinLai, Shuguang, or KR Audio.

Vacuum loss very apparent if gettering turns white and flakey. Otherwise doesn’t sound like a vacuum loss. I’d expect Upscale Audio will take care of you given their reputation. Have you emailed WE? Maybe a common burn in symptom? Although burning smell not good! 

Best of luck, let us know how it turns out.

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.