Are my new EL34 tubes bad?

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TrueTone500

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Okay, I just put in a new quad of GT EL34-M power tubes. When I tap on my amp, I can hear it through the speakers? It sounds kind of like when you knock on a reverb can, but it happens with the slightest tap anywhere on the amp. :confused: Is it possible a new set of tubes could be bad?
 
I know that tubes are naturally microphonic to a point, but this is crazy. I can lightly tap anywhere on the amp and it makes noise.
 
Found it! One of the power tube sockets was dirty. :)
 
I had bought a Randall RM50H that came with nothing wrong with the box packed with the original packing foam and when i took it out of the box both EL34's that were in it were destroyed, so the person that I bought the amp off of was quick to got to tubedepot.com and have another set of JJ EL34's sent, when those arrived and I installed and biased them they were fine for about an hour then started making this horrible crackling sound, so i swapped in a set of 6L6's and they worked fine so the tubes went back to tube depot, the guy who sold me the amp covered everything so a couple days later a new set of JJ EL34's arrived and I installed them and instantly one of them blew as soon as I hit the first chord.. and the dude who i got the amp off was willing to pay for the shipping and new tubes.. But I told him not to worry about it as he could do no better than he had been doing and since then ive had the amp up and running fine on my spare set of 6L6's.. I dont know if tubedepot got a really shitty batch of EL34's or what... I am thinking of trying a set of EL34's again but not a set of jj's... anyone have any suggestions? Ill be running the RM50H as a poweramp for my RM4 and ive got 4 very different modules in the RM4..
-mp-
 
A year or so ago I heard of some issues with the JJ 34's. Many people were avoiding them. Maybe you were dipping into that same batch.
 
I purchased a new quad of SED EL34's from Amplified Parts, and one of the tubes popped with less than 4 hours on the tube. One of the GT EL34-M tubes that I purchased from Sweetwater last week has a bulged top on it? I don't know if that effects the performance of the tube, but it's the same one that was giving me trouble... Sweetwater does not do returns on tubes, so I guess I will have to go through GT.

They just don't make 'em like they use to... :aww:
 
I have 3 good SED EL34's, so I guess I need to try to find one that is rated the same?
 
TrueTone500":3oxeqz8o said:
I purchased a new quad of SED EL34's from Amplified Parts, and one of the tubes popped with less than 4 hours on the tube. One of the GT EL34-M tubes that I purchased from Sweetwater last week has a bulged top on it? I don't know if that effects the performance of the tube, but it's the same one that was giving me trouble... Sweetwater does not do returns on tubes, so I guess I will have to go through GT.

They just don't make 'em like they use to... :aww:


Amplified Parts is the Storefront for Antique Electronic Supply which is CE Dist.

That being said, they don't burn their tubes in, just match them. They do sell Burned in sets of the SED EL34 at a slightly higher price.

The best advice is to get tubes that have been burned in at a minimum of 24 hrs, this weeds out the bad ones most of the time.
 
baron55":drz65392 said:
TrueTone500":drz65392 said:
I purchased a new quad of SED EL34's from Amplified Parts, and one of the tubes popped with less than 4 hours on the tube. One of the GT EL34-M tubes that I purchased from Sweetwater last week has a bulged top on it? I don't know if that effects the performance of the tube, but it's the same one that was giving me trouble... Sweetwater does not do returns on tubes, so I guess I will have to go through GT.

They just don't make 'em like they use to... :aww:


Amplified Parts is the Storefront for Antique Electronic Supply which is CE Dist.

That being said, they don't burn their tubes in, just match them. They do sell Burned in sets of the SED EL34 at a slightly higher price.

The best advice is to get tubes that have been burned in at a minimum of 24 hrs, this weeds out the bad ones most of the time.


http://www.valvequeen.com/

Laura's best at doing that shit ... Friedman get his tubes from her nao. :thumbsup:
 
baron55":t76bjdzx said:
TrueTone500":t76bjdzx said:
I purchased a new quad of SED EL34's from Amplified Parts, and one of the tubes popped with less than 4 hours on the tube. One of the GT EL34-M tubes that I purchased from Sweetwater last week has a bulged top on it? I don't know if that effects the performance of the tube, but it's the same one that was giving me trouble... Sweetwater does not do returns on tubes, so I guess I will have to go through GT.

They just don't make 'em like they use to... :aww:


Amplified Parts is the Storefront for Antique Electronic Supply which is CE Dist.

That being said, they don't burn their tubes in, just match them. They do sell Burned in sets of the SED EL34 at a slightly higher price.

The best advice is to get tubes that have been burned in at a minimum of 24 hrs, this weeds out the bad ones most of the time.
Are you serious? :doh: I swore I would NEVER purchase tubes from Antique Electronic Supply again. I purchased a quad of tubes from them last year, and two of the tubes took a dump after less than 10 hours use in my stock SLO100. Sneaky bastards!
 
They do have a lot of parts that would otherwise be difficult to procure, so I have to give them props for that. I guess it's a gamble when you buy tubes that aren't 'burned-in'. Maybe I won't be so cheap next time... :D
 
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