Markiii simul class retube,old question sorry.

burt reynolds · Oct 20, 2011

Can i run jj powertubes without damaging my amp? The guy i bought the amp from said i can only run mesa tubes without modifying the amp bias.
I know its fixed bias but we have an old fixed bias 5150,and an older fixed bias single rec,and we have retubed both amps with jj's and have had no problems and i really like the tone of them. I have done a lot of searching on here and google,and cant seem to find a straight answer on this. I realize the jj's may not be perfect as far as the bias is concerned,but can i safely run them?

I know there are other routes i can go And buy matched tubes for my amp but i live right by parts express and can pick up jj's cheap and fast.

pvandendungen · Oct 20, 2011

https://ssl.eurotubes.com/cart/index.php?page=view_products&category_id=6&sub_category_id=90

MrMarkIII · Oct 20, 2011

All the online sellers can fix you up - just tell them what amp you have.
The corollary being that you can't walk into GC and get the same service (unless you buy Groove Tubes).

burt reynolds · Oct 20, 2011

That eurotubes package looks great thanks for the info
The seller of this amp made it sound like i have to perform surgery on the amp to run anything but mesa tubes.

JAMz · Oct 20, 2011

Yep, just tell the guy the make and model and they should be able to provide the proper tubes. As I've been told, mesa amps run at medium bias. That is; the bias setting is not too hot or too cold.