News:
August 19, 2022, 07:22:02 AM

Author Topic: 12AU7 To 6SN7 Socket Wiring  (Read 129 times)

0 Members and 1 Guest are viewing this topic.

Offline photoduo

  • Newbie
  • *
  • Posts: 9
    • Photography / Video
12AU7 To 6SN7 Socket Wiring
« on: April 18, 2022, 06:57:38 PM »
So I would like to install an octal socket so I can use 6SN7's without an adapter.  I have quite a few real nice 6SN7's that were part of my fathers collection and some beautiful Bendix 6080's as well.  I have searched and searched and found a pin assignment chart from Grainger49 but that was for a Foreplay III.  Can anyone point me in a definitive direction.  I have read about others that have done the conversion but no where can I find specific info, especially for my Crack-a-two-a.  I should have listened more when I was young and my father was always trying to teach me electronics, however he did teach me to solder real well.

Will the following Pin Assignment Chart that Grainger49 posted work for Crack-a-two-a?


It has often been asked how to use the whole hole in the FP III, install an octal socket and use 6SN7s instead of the stock 12AU7s.

Here is a run down of tube pins that are equivalent:

12AU7 Pin   wired to 6SN7 Pin
     1                             2
     2                             1
     3                             3
     4                             7
     5                             No Connection
     6                             5
     7                             4
     8                             6
     9                             8

Thanks all!

Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 17163
Re: 12AU7 To 6SN7 Socket Wiring
« Reply #1 on: April 18, 2022, 08:16:17 PM »
That is the correct pin reassignment.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man