Would you still use these tubes? Or are they cooked?

[Headache]

I'd like your input guys, y'all have an extraordinary amount of tube knowledge that I don't have.

I pulled these from my second DSL when I bought it used. I always put new tubes in any amp I buy and then just keep the old ones as backups.
I was looking through my drawer full of tubes and found these and looked them over some.
They look toasted to me. But I'm no guru.
I would guess there may be 2 trains of thought:
1. Tubes either work or they don't, run em till they stop.
2. Don't run worn out tubes because they'll pop and ruin your amp eventually.

How to these look to your eyes? (They were working, and the DSL sounded great)

 

[mickeydg5]

Have them tested on a good transconductance tube tester.

 

[Headache]

Have them tested on a good transconductance tube tester.

Oh good idea! If you have one I'll mail them to you?

 

[Sledge Johnson]

Oh good idea! If you have one I'll mail them to you?

Surely someone in your area has a tube tester.
An HAM operator, a radio repair guy, a tube amp tech ?

You can check for grid shorts with a multi-meter.

Those tubes have gotten HOT !
My guess is biased too hot, bet they work though.
For how long ? Anyones guess.

 

[StingRay85]

They have been cooked though...

 

[Jon Snell]

I would test them in my AVO 163 but in the absence of a proper valve tester, measure the current at idle on each valves cathode and if they are close, carry on using them, eventhough they are Chinese.
Don't forget, they are in a Marshall, not a Fender. Reset the bias accordingly!

Here is an updated list of manufacturers used by Marshall;

edit: added valve list.

 

[playloud]

It's funny - these probably don't look any worse than the average set sold as "NOS" on Reverb/Ebay...

But, as others have said above, probably worth testing. If you have a light bulb limiter, you could at least rule out shorts by testing in the amp.

 

[neikeel]

Sure they have got hot - all tubes do. Unequivocally trashed tubes are those with white oxide powder (loss of vacuum) black smoke on sides of tube (redplating) and absence of flashing. Similarly if you gently shake it and it rattles - be wary.
These are far from définitive signs but a guide. I’ve got some old mullards that look knackered but test just ok on my CT160. Others pristine on the above observations are totally unserviceable.
Beg, borrow steal a tester or someone to do it for you.

 

[Headache]

I live in rural AZ. I will ask around, I think I know a guy who is big into HAM radio.

It's Probably going to be a lot easier to mail them somewhere.

 

[Sir Don]

Each to their own but if these were mine I'd bin them.

 

[Phoenician]

I live in rural AZ. I will ask around, I think I know a guy who is big into HAM radio.

It's Probably going to be a lot easier to mail them somewhere.

Maybe you can swing by to see Lowell at Hunt Amplification in Deer Valley.

 

[Headache]

Maybe you can swing by to see Lowell at Hunt Amplification in Deer Valley.

That's my guy actually ! Super nice guy.

I ended up mailing them to a friend on another web forum.

 

[mickeydg5]

Oh good idea! If you have one I'll mail them to you?

I would but I do not really have the time right now not to mention you, like many others, do not indicate where about you live much less what country.

By the way I have 5 mutual conductance testers.

Edit:
I see Arizona from the above information.

 

[Jethro Rocker]

They came from a working amp and haven't been used since. Therefore - They are still good at this moment. Could be ready to go but who knows? As backups one pair would only have to work for a short while. I got lots look like that that work that is not a tell tale sign of dead tubes.
Keep em as backups.