6080/6AS7 sparking

[jp.lichtenberg]

Hello,

I built my crack several months back and have not had any issues until this week. Now, when I turn it on, I have a lot of sparking that happens in the 6080/6AS7 tube. What could be causing this issue?

Thanks,
JP Lichtenberg

 

[Doc B]

it's most likely that the tube has developed an internal short. Try another 6080 and if that doesn't solve it do all your resistance measurements and report any values that are out of spec.

 

[jp.lichtenberg]

If it turns out to be an internal short, what can I do to prevent this in the future?

 

[Paul Birkeland]

Development of an internal short is often very random and very rare.  You may never run into this again.

 

[JamieMcC]

I had a 5998 once that would put on a good little firework show when it fired up with a handful of little sparks that would fly pinging around inside the tube. This display only happened when the tube was first powered on for a second or two then it would run fine. After about a week or so one channel went dead and the tube showed as having a short on my tester. I cant remember if this made a sound through the headphones or not but suspect I didn't have them plugged in when powering up which was my norm for powering up a new tube for the first time.