• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

6U10, 6AC10, 6D10, 6AV11 Tubes

Greetings,, Are the above titled tubes, & others like them, interchangeable in the precise sense the 12**7's are swappable with a resulting change in gain? Or is there too much 'other' stuff going on in those compactrons? In particular, My Ampeg
AC-12 calls for a 6U10, as do many, many Ampegs, and I wanted to know if the other Compactrons mentioned are drop in substitutes that may offer different, or more, amounts of gain?
Many Thnx, Kenny ॐ💃🪕
If you're swapping 12A*7s without any other changes to the amp, you're doing it wrong. And no, if the internals are different, you need the proper circuit evaluation/design to figure out if there is a compromise where two different pin compatible tubes can be used.
  • Like
Reactions: 1 user
There is no 'other' stuff going on in those compactrons.

6U10 equivalent to 2x 1/2 of 12AU7 + 1x 1/2 of 12AX7​

6AC10 and 6D10 both equivalent to 3x 1/2 of 12AT7​

6AV11 equivalent to 3x 12AU7​

Except for heater voltage which is 6.3V only in these compactrons.
However 8AC10 and 12AC10 etc etc etc also exist.


  • Compactron_Table_1.png
    120.4 KB · Views: 12
  • Compactron_Table_2.png
    118.9 KB · Views: 15
  • Compactron_Table_3.png
    159 KB · Views: 12