Lower gain tube in PI position

[nicknolte]

In a similar line of thought, how would a 12Au7 fare in the PI position?

 

[mysticaxe]

People often forget that even though a 12AT7 has the same pins as a 12AX7, and they're technically interchangeable, it's a totally different tube design. It's more of a utility-function tube, not a great tone-producing tube. I've always found AT7s hollow, harsh, and kinda sterile.

The Mullard 12AT7 is an exception. That tube is tone-town for under $30 NOS.

That was the tube I was using - a CV4024. I tried it in both V1 and PI in a couple amps and ended up pulling it out for current production 12ax7s. It wasn't all that to me...

 

[K-Bizzle]

I've tried a few different current production and NOS tubes in the PI.
Honestly in both my Randall Mts amps, my dsl, and my 333 I preferred the JAN12AT7 over anything else in the PI spot.
Seems to defizz, add some clarity, and give the amp a different feel that's hard to desrcibe. Personally I like it quite a bit. I guess it really depends on the amp and what you're going for.
However I do not like it in any other position. The 12AT7 is cold and thin and just nasty sounding (not in the good way) in tone spots.
I did like the 5751 in V1 of overly gainy amps if that's something ur looking for.