Dead Tube??

[Hetman]

Hey all,

Havent had much trouble with my Mesa heads before but I think I have a dodgy tube, when I turn amp on it is making a buzzing sound only. The amp actualy died at the end of band practice the other night and I have just turned it on again. Does this sound like a dodgy tube??

Cheers

 

[domct203]

What you describe is most likely tube related. What model Mesa is it? How old are the tubes? Does it buzz in all channels? This additional info will help us trouble-shoot.

In the mean time if you have any spare preamp tubes try swapping them out one at a time to see if you can find a bad tube.

If this is power tube related, make sure you have spare fuses.

Dom

 

[Hetman]

Hey Dom,

It is a 3 Ch Dual Recto and it buzzes in all channels, I brought the head second hand about 8 months ago, the previous owner said the power amp tubes were only a couple of months old (at the time). I'm not even sure how old the head is. The serial number is R-022139. It has been running with Sevetlana 6L6GC tubes in it. I do not currently have any spare preamp tubes......I may have to grab some.

 

[domct203]

Seeing that the head is second hand, I would put a complete re-tube on your "to-do list". I run the SED =C= 6L6's in my Roadster, great sounding tube. Make sure you get your tubes from a good supplier so you get tubes selected to run in a Mesa Amp.

Here are some things to try. Look at all the tubes for anything suspicious like a crack or burnt lettering. Try Hard Bypassing the loop to eliminate the FX loop driver ( V4 ). Also, if you run in "Tube Rectified", switch to solid state, remove the 5U4GB rectifier tubes and try again to eliminate them. Even if you exclusively use SS rectified, a bad 5U4GB can cause problems.

Get yourself a couple of spare preamp tubes, not only to trouble-shoot, but it's good insurance. At every gig I play I bring a spare quad of power tubes and 4 preamp tubes.

Good Luck,
Dom

 

[Hetman]

Appreciate your help, thanks. :wink:

 

[clutch71]

Anything in the loop? I have a Ibanez DE7 that, when hooked to a Boss Power supply, is "buzzy." If I run a 9v in it it's just fine.

Just a thought. Good luck.