Why does the Carr Rambler use a 12AT7 for V2?

[SFMUSICMAN]

I put in a short plate JJ's 12AX7 in V2 (along with new tubes for V1, long plate and V3, short plate - all 3 unbalanced) but noticed that the original schematic for V2 is an AT7.

Why would this lower gain tube be used here? Is it for the reverb and tremolo portion of the circuit? (see attachment)

There's only one input...

thanks

[statorvane]

Without seeing the schematic I'd suspect both triodes of the 12AT7 are used in parallel for the reverb driver. Typically the way Fender has done it.

[tubeswell]

Fender used a whole 12AT7 as a reverb driver because it has a the best gain vs current trade-off for a 12A_7 type tube. More current helps to drive the reverb pan's input transducer better. Whilst 12AX7 has a 66% higher amplification factor, it has a heck of lot less proportion of current output, compared to a 12AT7. With a 12AX7 in that V2 slot, you'll probably find that the reverb has a lot less ping

[SFMUSICMAN]

great guys thanks...I gotta get the JJ's 12AXT outta there then and put it in the PI position