rsm
Well-known member
My "new-to-me" 1976 Fender Super Twin has the following preamp/EQ tubes:
2 x 7025
1 x 12AU7A
1 x 12AX7A
1 x 12AT7A
I'm only finding NOS tubes for the ones ending in A.
The A means it works in both parallel or series wired heater circuits; without the A, they only work with parallel wired heaters.
How can I determine if the Super Twin has Parallel or Series wired heater circuits?
I don't want to pay for NOS if they're not required.
2 x 7025
1 x 12AU7A
1 x 12AX7A
1 x 12AT7A
I'm only finding NOS tubes for the ones ending in A.
The A means it works in both parallel or series wired heater circuits; without the A, they only work with parallel wired heaters.
How can I determine if the Super Twin has Parallel or Series wired heater circuits?
I don't want to pay for NOS if they're not required.