Help! Problem with tubes on mesa boogie 400+

jesuskno · #1 11-06-2010, 04:12 AM

Hello friends. I have a problem with my tube amp.
A few months ago I carried my 400+ amp a technician.
He changed all the tubes. Say me that the tubes of the stage
power are Sovtek.
Yesterday at 5 minutes I be playing a blue light appeared in the
back of the amp. I saw a tube doesn't work and the fuse was burned.
Today I open my amp and I see that the tubes do not put any manufacturer.
I thought about buying two matched Sovtek tubes. My surprise is that no what kind of tubes he put my amplifier. I'll ask the technician but also I ask you because I feel cheated.
Thanks.

Photos:

JimmyM · #2 11-06-2010, 05:02 AM

not sure what kind they are (the writing sort of looks russian so they could be sovtek), but it's not unusual for a new tube to go out occasionally.

jesuskno · #3 11-06-2010, 05:38 AM

I think, tubes are Sovtek 6L6GA.

JimmyM · #4 11-06-2010, 06:18 AM

ya, i don't think your tech did anything wrong. tube qc just isn't quite as good as it used to be, and you'll get the occasional bum tube more often than you used to, so tell him you need another tube spec'd to the ones he put in there before and you should be good to go.

jesuskno · #5 11-06-2010, 06:31 AM

Thanks JimmyM.

BassmanPaul · #6 11-06-2010, 11:29 AM

They SHOULD be 6L6GCs. If in fact they are GAs you can expect the rest of them to die in fairly short order. The GA cannot cope with the service requirements of your amp.

JimmyM · #7 11-06-2010, 12:44 PM

certainly they'd be 6l6gc's then, wouldn't they? can't imagine a tech using anything but.

jesuskno · #8 11-06-2010, 01:11 PM

Yes Paul, they are Sovtek GAs NOS. The technician say to me. They are matched.

BassmanPaul · #9 11-06-2010, 02:20 PM

Look at the data sheet for the GA and compare to the GC. They're not even close.

jesuskno · #10 11-06-2010, 03:02 PM

I will now replace 2 GAs matched, next year I will
consider changing all the other tubes.