Klem,
Sorry for the long winded explanation to follow:
I've got a pair of these mics, and I performed the capacitor mods (styrene's etc). Using the PAZ analysis meters (VST Plugin), this changed the response of the mic by boosting the low end from about 40Hz through 200Hz by about 1.5dBFS.
What the meter didn't show was a subjective loss of "harshness" I'd estimate to have existed between 2-6kHz. This was not necessary a level loss in that frequency range, but a noticable smoothing out of the response.
Taking things a step further, I then proceeded to clean the PCB's with alcohol. There was a lot of flux. A post on this forum suggested it.
Another test showed little to no change on the PAZ meters during use, but at rest, the self-noise at high gain dropped. I did not record those levels, sorry.
During use, however, the subjective sound was more "open". In my opinion, the lower noise floor is revealing some dynamic content.
Then I did a blind AB of this mic with both stock cardiod and the $40 omni capsules against a pair of Neumann KM184s on acoustic guitar.
The 2 other people in the control room said there was a slight difference in sound between the 2 mics, but that neither sounded better than the other.
Gain settings did have to be slightly changed to match levels for the test.
I don't know of any replacement capsules for the mic, but I think that there may be differences in early capsules versus later capsules. My pair is from the introduction of the mics. I've read others saying that the new mics are not as good. (I have the 603S version).
In any case, the striking thing was hearing the cleaned PCB, cap-modded mics with the MXL OMNI capsules! WOW!!
If you haven't tried them, give them a shot. :green: