That may just be the perfect solution!
But, not much for me to do as far as a project...
But it will solve my problem...
cheaply...
I can use perfboard to go from the mini-xlr jack to the capsule end and keep the M1290 brass bodies.
I haven't received the capsule assemblies yet. So, I don't know for sure, but I should be able to mount the TSB-120A spring steel loaded FET section on that perfboard with epoxy to mate with the capsules.
Man, if I could find some m1245 brass bodies (much shorter than the M1290's) it would be perfect!
Thanks Jon! I am worried about that FET though. Everything I've read says it's not that great. But, of course I defer to your knowledge and judgement about that. The guy I bought the TSB-120A assemblies from said he matches them +/- 1db.