Can using a bad tube hurt an amplifier?

@buellrider97 

Yes we suffer reliably issues, tube issues and the jabs from the SS crowd and now the class D crowd. 

but those other amps are not bulletproof, I might argue they are no more reliable than tube amps. I wouldn't say I was an early adopter for class D amps, but both the Nord's I bought about ten years ago with the Hypex smps1200a400 power supplies lasted exactly 4 years before they expired. They have since revised them, with elimination of one prone to fail capacitor- not sure if they last longer now. 

I have also had issues with Mcintosh amps. Nothing lasts forever. 

Is it -1 for tubes or +1 for SS? Who’s keeping score?

When you have red plating with tube amps until one measures plate voltages you won't know for sure if its tube failure or amp issue, you may be damaging more tubes if amp is the issue. Tubes going bad without red plating likely lost vacuum, sometimes this seen as interior of tube enveloped in blue haze, other times not, another sign is white getter.

Just had Fedex drop off the replacement Gold Lion 300b, inserted it in the amp, and voila, music is playing again. 

Just one $5 220uf Rubycon capacitor was all that needed replacing. 

Lucky the cap went first, and not after various other parts as in this component:

https://www.youtube.com/watch?v=ZaEiO_9qMwY

@kennyc +1