Serge Ring Modulator
The VC Ring Modulator (RING) has Manual and Voltage Control of modulation from passing the input signal unchanged through Amplitude Modulation to full Ring Modulation
There is manual control of the Carrier Amount that includes waveshaping. And the module has 80db of carrier rejection
My Serge Phaser was bought as a semi-kit from SMMS (Serge Modular Music Systems) in the early 1980's
There is currently no DIY builds available for this module. The design uses the currently obsolete CA3280 OTA