A Mesa is biased at... what?

[joey_truelove]

I'm curious as I'm about to re-valve/ tube my 50/50 and I don't want it too cold or too hot, just slightly on the chilly side

 

[disassembled]

don't worry about it. Any new production tube will work. If you want you can call mesa and have them recommend the best tubes for it. Do you have any gear that measures plate current? If not then you won't know how "chilly" or how "hot" your tubes really are.


Greg

 

[joey_truelove]

don't worry about it. Any new production tube will work. If you want you can call mesa and have them recommend the best tubes for it. Do you have any gear that measures plate current? If not then you won't know how "chilly" or how "hot" your tubes really are.


Greg

Thanx, mate! No, sadly enough I never saw a need for such a gear and didn't buy one. Maybe I should have.

I thought the bias in my Fifty/Fifty was the same as in just any Mesa amp? I do know however Mesas are biased rather cold so middle of the "normal" scale would be a touch chilly I believe. Maybe 6 or 7 on the GT 10 graded scale would be a fair guess.

 

[disassembled]

The thing with that is what does a 6 or 7 mean? Does it mean it will draw a certain amount of current on every amp? Nope. Every amp is different (voltages) and therefore that's just a gimmick to draw in customers. You are better off going with a distributor like dougstubes or eurotubes and specifying what you want out of the amp (earlier breakup, high headroom, etc). I bet if you take a bunch of different sets of tubes from groove tubes that are all labeled with the same number that you will get different current readings.

I honestly doubt you could tell the difference between an amp that draws 20mA and one that draws 30mA unless there was serious cross over distortion going on. The hotter the amp is biased the less clean headroom you have.


Greg