Which 12ax7 choice for cathode follower?

[Frostbite Slim]

[quote="sergio"]I used an RFT 12AT7 NOS in CF stage , good choice!
S.[/quote]

That's what I would think. AT7's offer much more current to drive a CF stage,so why do many amps call for the AX7?

[sergio]

Take in mind you will be always in Class AB2 with that CF dc coupled , with bot AX and AT type.
I used AT for an experiment and I like it. Bias resistors value changed also!!

S.

[Frostbite Slim]

[quote="sergio"]Take in mind you will be always in Class AB2 with that CF dc coupled , with bot AX and AT type.
I used AT for an experiment and I like it. Bias resistors value changed also!!

S.[/quote]

Sergio, thank you. I'm really starting to believe that there are more well suited tubes for CF's than the 12ax7. Maybe the AX7 is more commonly used for availability sake?

[martin manning]

!2AX7 is about 1/5 the current drive of a 12AT7 or 12AU7. Ok for a CF driving a tone stack, but the higher-current tubes are better suited for driving power tubes.

[CHIP]

Take in mind you will be always in Class AB2 with that CF dc coupled , with bot AX and AT type.
I used AT for an experiment and I like it. Bias resistors value changed also!!

S.

I'm glad you mentioned that the bias will change.
Mine went up 20ma when swithching form 12ax7 to 12at7.

[butwhatif]

I like Mullard 12ax7
reissue