#1
ok so i have aquired a new amp today, a B-52 AT-100 half stack. (NAD to come soon. i promise) i got it home and started setting it up with my rig when i noticed one of the tubes glowing brighter than normal. the amp started to make poping noises and stuff but overall still functioned. the tube is a sovtec 5881 can i replace it with a groove tube 5881 until my new tubes get here and play on it a bitor should i just leave it be?
as always thanks!
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Michael Kelly Custom Shop Plum Telecaster
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It is NOT trash metal it is tHrash metal...get it right
#2
Are the plates themselves glowing red, or are the heaters just brighter? Brighter is generally ok, as long as it's a steady brightness and not pulsing or flashing.

If it's actually redplating, turn the amp off immediately and get a new set of tubes and a re-bias.
Don't ever replace just one power tube - you need a matched quad of power tubes. Replacing one redplating tube will make the problem worse.
#3
there is one spot on one side of the plates that is glowing a bright red, like brighter on the inside. the top and bottom of the tube glows normal like the tubes in my BV. no flashing or blinking just a steady bright glow. ill take pics in a little bit
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Michael Kelly Custom Shop Plum Telecaster
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EVH 5153 50w
Jet City 2x12
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It is NOT trash metal it is tHrash metal...get it right
#4
These amps are biased quite cold, redplating could be a sign that something has gone quite wrong in the amp. It is very unusual for a tube to redplate in this sort of amp. If it is truly redplating, you need to turn the amp off immediately and not use it until you can get it to a tech for a diagnosis and a new set of tubes.

Is it a cherry "hot metal" red, or is it a bright white or white-orange glow like the top and bottom of the tube (heaters)?
#5
its a cherry hot metal red
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Michael Kelly Custom Shop Plum Telecaster
Michael Kelly Custom Shop Plum Patriot


EVH 5153 50w
Jet City 2x12
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It is NOT trash metal it is tHrash metal...get it right
#7
tuesday it goes in then. no sweat. thanks roc!
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Michael Kelly Custom Shop Plum Telecaster
Michael Kelly Custom Shop Plum Patriot


EVH 5153 50w
Jet City 2x12
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It is NOT trash metal it is tHrash metal...get it right
#8
It's a good thing you caught it. A lot of people don't notice redplating until it causes other problems. Let us know how it turns out.
#10
What type of tubes did you have in it? Both the VK and the B-52 have very cold bias from the factory, so it seems more likely that the tubes were at fault than the amp, especially if the fuse blew and a replacement set works fine.

If Sovtek is putting out power tubes bad enough to redplate in those amps, I'd be interested in knowing it.
#11
The tubes were crap, brand new amp, tubes didn't even make it 3 months. They were Ruby tubes stock. Both amps are notorious for crappy tubes, so before you suspect the amp, suspect the tubes, because they are crap. After a retube, they hardly have any tube related problems until it's that time again.
#12
thanks again for the help Roc, i was planning on bringing it in due to the fact that im sure these are the original tubes that shipped with the amp. im sure that the guy i got it from had no idea what was going on with it. it wasnt lit up like this when i tried it out but i did take a pretty bad bump in my truck on the way home. im not sure if that caused it but like i said i had plans to bring it in anyway.
Live Rig
Michael Kelly Custom Shop Plum Telecaster
Michael Kelly Custom Shop Plum Patriot


EVH 5153 50w
Jet City 2x12
Custom Board

It is NOT trash metal it is tHrash metal...get it right
#15
the at100 has sovtec 5881 tubes in it right now. i have ruby 6l6gmstr's in my blue voodoo and they have been great so far. im most likely gonna order those again. the wife isnt too thrilled that i get what she calls a "new" amp and it has to go directly into the shop.

i must say though before i noticed the red plating going on, the at100 amps sound pretty nice.

crap i just saw what you said about rebranding sovtecs......maybe ill look for something else.
Live Rig
Michael Kelly Custom Shop Plum Telecaster
Michael Kelly Custom Shop Plum Patriot


EVH 5153 50w
Jet City 2x12
Custom Board

It is NOT trash metal it is tHrash metal...get it right
Last edited by iheartgun at Oct 10, 2011,
#16
The GCMSTR are from the Chinese factory - Ruby rebrands a bunch of different kinds of tubes, so they're not necessarily Sovteks. 6l6-CZ are JJs (Made in Czech Republic), and I think the ones without a designation are Sovtek, though Sovtek owns the Svetlana trademark, so they could be Svetlanas as well, which is confusing since Svets are quite nice tubes.

Either way, I would not pay the rebranding fee. Grab some JJ or Tung-Sols from Tubedepot.com or Doug's tubes.
#17
im taking a look at dougstubes right now. ive ordered from there before i really like his site but there are so many choices. i do like JJ's and i think i might pick up something different for the picovalve while im at it.
Live Rig
Michael Kelly Custom Shop Plum Telecaster
Michael Kelly Custom Shop Plum Patriot


EVH 5153 50w
Jet City 2x12
Custom Board

It is NOT trash metal it is tHrash metal...get it right
#18
And just to confuse matters further, SED are actually real Svetlanas, New Sensor (the Sovtek people) bought the Svetlana name. SED are made in the old Svetlana factory, Svetlanas aren't.
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#19
this is quite confusing. so who actually makes "new" tubes that are worthwhile? it seems to me that most companies rebrand everything rather than manufacture new tubes

oh yeah and i just ordered a matched quad of JJ 6l6gc for the b52 from eurotubes. 70 bucks usd is not too shabby. i guess till the new tubes come in ill be putting the b52 cab through a workout to see if i want to keep it or keep my 5150 cab. someone is gonna get flipped for cash.
Live Rig
Michael Kelly Custom Shop Plum Telecaster
Michael Kelly Custom Shop Plum Patriot


EVH 5153 50w
Jet City 2x12
Custom Board

It is NOT trash metal it is tHrash metal...get it right
#20
The best quality output tubes are SED followed closely by JJ
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band