Is my 300B tube dead?

[Evenharmonics]

I have two 300B Tubelab SE amps, one stereo and one mono. They all use Valve Art 300B tube. The one in my mono may be gone beyond repairable point but I would like to double check with you guys.

Here is what happened. I started to hear crackle, pop and hiss from my mono amp couple of weeks ago. I took the tube out and checked to see if solder is bad somewhere but didn't notice any visually. I put the tube back in and all was well. Yesterday, the noise came back. I swapped the tube with the one in my stereo amp and the noise followed the tube. Not only that, the bias ran away on the suspected tube and the fuse in my stereo amp blew.

This tube was purchased new from Antique E. S. and used for about 200 hours. Is this tube gone?

[Frank Berry]

Sounds like the tube is history.
Is there a warranty on the tube?

[Evenharmonics]

It came with 90 day warranty but that was 10 months ago.

[kevinkr]

I had a lot of problems with Valve Arts 300B in the past, similar symptoms over a similar time frame, the extra money for a set of JJ or EH is money well spent IMHO.

[Evenharmonics]

Is 90 day warranty pretty much all I need? Considering my next 300B will be a different brand and I wonder if it's worth the extra cost of extended warranty. In other words, if it's going to fail, it would happen rather earlier than later I suppose. Or is it different for 300B tubes?

[Evenharmonics]

This really is a strange coincidence.
It turns out that the culprit was bad solder at one of the pins of output tube socket. What I didn't expect was to have this happen on both amps (mono and stereo) at the socket I plugged it into which made me to think that the problem followed the tube. I re-soldered them and now it's back to normal.

This tube is not defective and I apologize if I mislead anyone.