12AX7 Biasing?

[relaxo]

I know this must be a stupid question for most of you, but I've been searching manuals and online about biasing info regarding the 12AX7 type tubes in the RT2/50, the RM4 and the modules. I have found zero info. Should I take this as a hint that you cannot bias these or you do not need to?

Thanks, Scott

 

[hotlicks2go]

You don't bias preamp tubes as you do the power tubes. You should use current balanced tubes for phase inverter use. I believe these are the 2 outside tubes.

 

[relaxo]

You should use current balanced tubes for phase inverter use. I believe these are the 2 outside tubes.

You mean in the RT2/50? Do the modules or the RM4 use any current balanced tubes?

Thanks