Schoeps CCM capsule polarization voltage is contaminating 96 kHz recordings

I’ve been using a pair of Schoeps small diaphragm condensors (CMC6) as my main field recording kit for a couple years now. Usually, two wide cardioids in a stereo ORTF configuration. They sound great but for hard effects, I wanted to have an option for recording in a stereo M/S configuration. So I picked up their miniature bidirectional mic (CCM8), to use as a side channel with my current CMC6/MK41 hypercardioid working as the mid channel.

That’s when I discovered a bit of an issue with the CCM line of microphones.

The CCM8 polarizes it’s capsule with a 27-30 kHz DC voltage. This voltage is passed through to the mic pre, and will show up on a 96kHz recording. Below is a spectrogram showing a 96kHz recording I personally made with a CCM8. As you can see, the vertical frequency range is zoomed in to 27.7kHz and a solid DC frequency (with slight drift) is present throughout the 14min recording

According to a representative from Schoeps:

“The customer is measuring the internal DC/DC converter for the polarisation voltage. This happens at 27 to 30 kHz. This should be inaudible… the CMC 6 with MK 8 could be a choice as the CMC 6’s DC/DC converter works at @ 1.8 mHz.”



So you say “its 27 kHz, dog, you can’t hear that”. Which is true, dog, up until the point at which I want to pitch shift the recording down to half speed for sound design purposes

This isn’t a terribly big deal - I’ll return the mic and get a CMC6/MK8. But I think the sound design community who often rely on Schoeps in their field recording rigs should be aware of this issue.