12AT7 vs 12AU7, Interchangeable? Pros and Cons? ...

joeinid

joeinid

Super Moderator
Joined
Apr 4, 2013
Messages
18,722
Location
NY
Is the 12AU7 basically a lower gain version of the 12AT7 tube?

I'm using the new LTA MZ2 as a preamp and loving this little thing. It's doing an amazing job and comes standard with 12AT7. I am looking for a bit lower gain and understand that the 12AU7 should be a lower gain drop in replacement. Any thoughts on the 12AU7?
 
Last edited:
Check with the manufacturer. In some cases you can, specifically if you're trying to lower the gain, but in many cases you cannot.
 
Joe.......A 12AX7 and a 12AT7 tube are directly compatible and can be swapped. The primary difference is the tube gain. A 12AX7 has a gain factor of 100, whereas a 12AT7 has a gain factor of 60. The 12AT7 can also be substituted with a 5751 tube which has a gain factor of 70.

The 12AU7 is not considered a satisfactory replacement for a 12AX7 or a 12AT7. The 12AU7 has a gain factor of 19.
 
From the Linear Tube Audio website description of the product in question.

"We now offer NOS 12AT7 tube options in the Tubes section. Purchase a pair to be installed in your amp or just an extra set. 12AU7 tubes also work in the MZ2, though the gain will be lower. This will only make a noticeable difference if using certain headphones or speakers. "
 
You must log in or register to reply here.
Back
Top