upgraded capsule now only hum ?

I put a bees knees capsule in a aphex 460 , Didn't think of if the psu needed to be changed
[ I don't know if it does ] but all i get is a hum like there's no ground [ which I'll check for ]
but thought I'd ask so i don't miss the obvious  [ or stupid ]
tia

I can think three options, capsule hooked up wrong, broken capsule or the "scariest" option: polarization voltage from the PSU too great and membranes get sucked to the backplate. Could damage the capsule in long term. I don't know the recommended polarizing voltage for your capsule (K7?) but some Apex PSU's put out 80V which is rather high. Before doing anything else I would disconnect the capsule and check the polarization voltage (measure before the high value resistors). 60V would be safe, though the capsule may tolerate higher voltage, Ben will tell. Information might be found somewhere here also.

I learned the harmfulness of the too high pol. voltage "the hard way", luckily before any serious damage happened to my wonderful CT12 capsule.

I'm sure you know, but anyhow ... If you test the mic without the body (shell) you'll get an awful lot of hum.

Thanks for the replies , put the chinese one back in and it's fine
can you meter a capsule ?

What capsule is it, and what's your polarization voltage? Measure voltage before the large (ca 1Gohm) resistor, as the impedance is too great for most meters.