Pretty easy except that dealing with SMT parts is a PITA. When assembled they look like this:

The RK-12 capsules fit right into the existing silicone shock mounts in the headbaskets. Easy.

I have another pair of K-5000 bodies with RK-12s and “Super Schoeps” low capacity front ends, so a comparo is in order. For grins, a Schoeps RK-47 in K-5000 body and a Schoeps RK-12 in a MXL 990 body were also compared to the new mics. So here are a bunch of frequency runs.


#1837 (green) vs #1868 (yellow)

matched pair of TL/C mics


#1837 vs #1868



#1837 vs #1868


Fig. 8

#1837 TL/C

Card (green) Omni (yellow)

#1837 TL/C

Card (green) Fig.8 (yellow)

The sound check of these mics is here.

A few other measurements made on this circuit with a 100pF dummy capsule:

Gain vs feedback cap, no cap = 0dB;

10pF = -3.4dB; 25pF = -5.9dB; 48pF = -8.7dB; 68pF = -10.7dB; 115pF = -13.4dB.

@100mV (280mV p/p) out w/10pF, 2nd harmonic = 0.5%; @ 10mV out, 2nd = 0.05%

The page is getting long, so comparison with other designs continues on the next page.