Dead Tube Amp. Pointers requested.

[s5c6ihLW50]

I have the Crate V5 amp and at first (for a while) it sounded like someone was changing between dead radio stations.

I opened it and just retightened the ground screws and that worked for a bit.

A few days ago, I was playing clean and it sounded decent and when I hit the OD pedal it "farted" and died and smelled a bit (pun partially intended)

I opened it again and found all the caps were still fine and the fuse is intact.

I plugged it in with no load and the EL-84 tube was sparking (inside), it looks like a 4th of July party in there. So I pulled the plug.

With these non-technical descriptions that I posted, what could be going on?

Cosmetically everything looks fine.

[scorpio]

I am by no means a tech but have learned from the school of hard knocks. Since it smelled a bit, I would say the transformer was on the verge of failure but still might be good. A tube can fail and take out other components. I would suggest putting another EL84 in it and seeing if that migh solve the problem especially since the one in it is "sparking". Do not let it run very long if you notice the same problem.

[RackCrew]

While I'd certainly look at the tubes I think it would be wise to take it in to a tech and check the PSU/transformer related items.

Caps can also look fine but may still be toast.

[Blue Strat]

Caps can also look fine but may still be toast.

+1. Burning smells are most often associated with resistors, but a transformer issue isn't impossible.

First tip: NEVER operate a tube amp without a load.

The cheap possibility is tubes. You can try that and, worst case, end up with some spare tubes that you'll need soon enough.

More expensive route (and more likely to provide real answers and results): Have an amp tech check it for you. Best case, it's tubes and you have to pay for the tech's time in addition to the tubes.

[s5c6ihLW50]

Thanks all!

I replaced the EL-84 (JJ replaced with a similiar) and the 12ax7 (sovtek replaced with JJ).

And all seems normal now. I am still concerned about transformer but will have someone check that.

:)

[cap47]

It may only have been a bad power tube! You will find out if it works OK, just use it! You can always have a tech check it later.

[Blue Strat]

Thanks all!

I replaced the EL-84 (JJ replaced with a similiar) and the 12ax7 (sovtek replaced with JJ).

And all seems normal now. I am still concerned about transformer but will have someone check that.

:)

Transformers are the least likely components to go. If the amp is performing normally it's NOT a transformer.

[Structo]

Transformers are the least likely components to go. If the amp is performing normally it's NOT a transformer.
Yes but operating a tube amp without the speaker connected is a good way to lose that output transformer in a hurry.

The sparks and arcs in the tube were the symptoms of that activity. ;)

[Blue Strat]

Yes but operating a tube amp without the speaker connected is a good way to lose that output transformer in a hurry.

The sparks and arcs in the tube were the symptoms of that activity. ;)

Yes, but since the amp is now working fine....