Hi,
I am going to experiment with different tube brands with my M4 today.
I'll have some JJ83,Mullard 12AT7,Tungsol12AX7,Sovtek12AX7,EH12AX7 etc.
I want to try Mullard 12AT7 in different positions.
Is there any rules are 12AT7 tubes allowed instead of 12AX7?
So can I put it for example first...