Uberschall blowing fuses/faulty power tube

Tongue_Druid

New member
1st time poster, long time lurker! Did some searching here & there & wanted to see if anyone had a definitive answer. Got a new Uberschall in January stock with EL34's. Hooked into the Uberkab. First tube amp I've ever owned. I went to play it the other day and 10 secs after turning it on (just on standby to warm up) it was making some pops/crackles. I looked in and could see one of the power tubes faintly firing off little blue lights with every crackle. Turned the amp into full ON and it went away, played for an hour. Next day same thing, only it blew the main fuse when I switched it into ON. Replaced fuse, turned on again, blew the HT fuse. That same EL34 that was flickering made a huge flash when blowing the fuse.
So, my obvious answer would be to replace that tube. Do I have to buy a set of quads matched? I've heard both "wive's tale" and "yes, it's imperative" on that subject. As long as they're close can I bias the amp to make sure none are running too hot and be done with it?
It strikes me odd that a new boutique amp with JJ EL34's would have issues after 2 months of light use. Could this be indicative of a greater problem? Yes, the amp is matched at 16ohms to the Uberkab. I have it plugged into a $45 power strip with a high joules surge protection, the "ground" and "protected" lights have always remained green. Only a lamp and my MXR iso-brick share the strip. Really :confused: on this.
Thanx to anyone in advance for your help!!
 
The power tube is bad, you need to stop turning it on until you get it replaced, otherwise you are going to damage your amp. And yes any tube can fail with very few hours on them, it's actually very common.

Now that being said, you can replace one power tube, IF the quad set has labels on them that describe where they were purchase, and a number describing the bias point.
The bias points are not universal because everyplace that matches/sells tubes has a different method to do the matching, therefor that number is usually only meaningful to the company that sold the tubes.

If you got the amp new, you should contact Bogner, and they should send you a new set.
 
Thanks CrazyNutz! That's what I hoped/assumed, but "assuming things" without educating yourself is never smahhht. I emailed Bogner but they responded with a brief "prob just the tube, see if your tech has some lying around that match." Looks like I'll skip ahead to formalities and the warranty rigmarole now. Thanks again!
 
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