These circuits do two things. They load the cartridge with aproximately a 100 K resistance and they attenuate the output of the cartridge by about 30 db. The attenuation is necessary beacuse the output of a ceramic cartridge is much higher than that of a moving magnet. I wonder if it's output should go into a RIAA phono stage or a non equalized low level input such as a mic input. Either of these circuits can get rid of the distortion caused by overdriving a low level input.

In the integrated amplifiers from which these circuits came, the same RIAA equalisation stage is still used for the ceramic cartridge option. This isn't strictly correct, although loading a ceramic cart appropriately will make it behave somewhat like a velocity senstive magnetic transducer.