Basic Question: Lightning inside 6550

[mikejennens]

I have a Jolida SG502 I was listening to. One of the 6550 tubes kind of lit up with a blue flash. Everything went dead. I'm guessing the tube died, but is that common? Is it a sign of any other damage?
Thanks,
Mike

 

[PRR]

> Is it a sign of any other damage?

No way to know until you investigate.

I was zooming my 1979 T-Bird up the hill when it just went dead (not even lightning). Being Ford, there's many possible reasons, and I knew most of them, and could fix most of those at roadside. This time it took a couple days to find the odd problem. (Distributor did not turn when the engine was turned. Dist gear was stripped. Why? A timing-weight inside the dist had come loose and jammed the shaft. Nobody I asked had ever heard of such a thing.)

Depending on my mood, I might just replace the tube, or I might open it up and look/smell for damage, do basic tubes-out checks, etc. Your choice, also your comfort level, recalling that any 6550 amp is on the high side of Lethal Voltages.

 

[mikejennens]

> Is it a sign of any other damage?

No way to know until you investigate.

I was zooming my 1979 T-Bird up the hill when it just went dead (not even lightning). Being Ford, there's many possible reasons, and I knew most of them, and could fix most of those at roadside. This time it took a couple days to find the odd problem. (Distributor did not turn when the engine was turned. Dist gear was stripped. Why? A timing-weight inside the dist had come loose and jammed the shaft. Nobody I asked had ever heard of such a thing.)

Depending on my mood, I might just replace the tube, or I might open it up and look/smell for damage, do basic tubes-out checks, etc. Your choice, also your comfort level, recalling that any 6550 amp is on the high side of Lethal Voltages.

Thanks. I emailed the folks at Upscale Audio. I was told more than likely the tube went bad. I think I'll look at the amp with the bottom plate removed and see if anything looks bad/burned/damaged/etc. I'll replace the fuse, power the amp on, and see what happens. If nothing happens, I'll order a matched quad of the tubes, install them, adjust the bias, and see what happens. Depending on the results, I'll either listen to more music through my Jolida or listen to more music through a different (solid state) amp.

Thanks again for the reply.
Mike