Marshall 2203 Keeps Blowing Expensive 6550 Tubes! 

I really hate to say it, but maybe some tube amps aren't practical or economical to keep repairing. Is this vintage 1980s Marshall JMP 2203 Lead Master Volume head one of them? I installed Sovtek 6550 tubes from CE Distribution, the wholesale arm of Antique Electronic Supply, aka TubesandMore.com, but they keep blowing up prematurely, despite biasing to 70% of max plate dissipation at idle. Then to top it off, they refused to replace the burnt out tube! The only solution is to bias much colder and rant to RU-vid.
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#Electronics #Amplifier #Repair