I Have a tube mic that acts up sometimes. The mic is a C.S.D. "custom sound designs" a company that i have found no info on. It uses a 6201 tube 'at least that is what was there when i got it" The strange thing it does is, sometimes when i turn i on, the pick up pattern has switched to the other diaphram meaning 180 degrees. it sounds fine on the back and all the other 9 pick up positions still work fine it's just that its all 180 reversed. Even stranger is how to temporarly fix it. once it is reversed it will stay like that until i take it apart AND put it back together with it still on, (dont ask how i found out). Any ideas? I have replaced the tube with no change, but with a bit less noise.