Schoeps M221A - PSU issue

[saint gillis]

I tried to change the 3,2µ electrolitic and the 2n5 ceramic , but the mic is still a bit noisy... do you think it is the tube?

 

[saint gillis]

  In fact I'm asking help from everybody in the forum, the mic was a bit noisy (some amount of white noise not proper for acoustic guitars but ok for drums), I changed the 3,2µ and the cermamic heater supply decoupling cap , it didn't change anything.
Then I tried to change the 180M resistor polarizing the capsule from HV with a 150M and a 30M in series, and I checked every solder with a lot of care, then it was worse, so I put back the original 180M resistor, and and was still bad : ocean noise, sometimes dissapearing and getting quite ok (even better than than in the beginning.. or it's just my imagination) sometimes coming back really bad...

  Did I somehow traumatised the tube, or is there some other things to try to fix the problem?

 

[saint gillis]

Also the filament voltage was 4V at the psu side but 3,81V at the mic's side, so I rised it a bit so it is now 4,1V at the mic's side.
Maybe some components became hot during soldering and caused issues, because one day later everything seems like at the beginning, so a bit noisy... I don'y know what else to try... any help would be appreciated