Use any Mic with the MKAdapter for MicroKorg vocoder - YouTube
KORG microKORG Series Synthesizer Vocoder Keyboard Condenser Microphone Mic | eBay
Korg Vocoder Condenser Microphone for microKORG XL, microKORG XL+ Synt - Pixel Pro Audio
Amazon.com: Korg microKORG Compact Modeling Analog Synthesizer with 8 band Vocoder and Microphone with keyboard bench and digital piano headphones : Musical Instruments