These also work for the FP III but it isn't a Legacy Product. Also, I don't know what can be substituted for the regulator 12AU7 in the FP III Extended.
This thread is getting started to explore tube types, different numbers, that can be used in the Foreplay (1) and 2 without any circuit modifications. That is, drop in equivalents. I might later add a list of those that require socket rewiring and the octal/loctal tubes that also work.
These are the ones I have found. I will modify the OP with others as posters contribute other numbers.
If anyone finds that I have a tube with the wrong pin out, or higher heater current than the FP 1 & 2 can supply please post and I will modify the OP accordingly.
FP 1 & 2 Tube Equivalents (in numerical order):
12AU7(A)(WA)
5814(A)
5963
6067
6189(W)(WA)
6680 (also WL6680)
7316
7489
CV10323 (from Duncanamps)
CV10666
CV4003
CV4122
CV491
CV8155
CV8221
ECC186
ECC82
ECC802(S)
E8025
E82CC
I didn't find a USSR Military Surplus equivalent, my cheapskate favorites, for this tube.
Tubes requiring a new tube socket or rewiring of the existing 9 pin miniature socket:
6SN7
7N7 (Defeat the lock on the tube socket or you are in trouble)
Please post others.
