I Screwed Up

[fastredponycar]

I played a 5 band show that had a Marshall Jubilee in the backline.

The guitarist, in the band before us, put his amp on top of the Jube and unplugged the speaker wire (from the Jube) so he could use the speaker cab below.
He had left the Jube on, without the speaker wire connected, throughout his 40 min set.
As we were swapping places, I noticed that the Jube was on with no speaker wire connected.
I mentioned that a tube amp can blow if it's not plugged into a speaker....
His reply: "I wanted to keep it warmed up for the next guy"

Again, this is fine too. A few amp builders have all told me that running the amp on with no load as long as nothing is plugged in and making sound, everything is fine.

[Guitarbilly]

I played a 5 band show that had a Marshall Jubilee in the backline.

The guitarist, in the band before us, put his amp on top of the Jube and unplugged the speaker wire (from the Jube) so he could use the speaker cab below.
He had left the Jube on, without the speaker wire connected, throughout his 40 min set.
As we were swapping places, I noticed that the Jube was on with no speaker wire connected.
I mentioned that a tube amp can blow if it's not plugged into a speaker....
His reply: "I wanted to keep it warmed up for the next guy"

Again, this is fine too. A few amp builders have all told me that running the amp on with no load as long as nothing is plugged in and making sound, everything is fine.

This is true. There's no risk if there is nothing coming through the input. However, if there is an issue with a tube popping, hissing or crackling, or if something causes a noise interference that counts as "sound" and can cause problems. So don't leave the amp on without a speaker connected unless the amp has a protection circuit that mutes the whole amp if there's no cable in the speaker jack (the EVHs and the 20w Marshalls are like that but the Jubilee is not).

[spawnofthesith]

Interesting side tangent….

Friend of mine recently fried his Revv…he turned the amp on (still in standby) before connecting to the cab, he fumbled on the way there and Ibthink he said contacted some metal somewhere else on the cable and it was cooked. Haven’t heard the rest of the story yet of what actually got cooked I know he has it in for repair