The only thing that plugs into the mic input of a Soundblaster card (or any other sound card having a mic input, for that matter) is a computer microphone like the one that might have come with your card, put on a stick and a stand, or built into a pair of headphones for gaming etc. It has the plug configured in an odd way; ground is ground, and tip is signal, but the ring expects 5 V DC from the Soundblaster. The mic amp thrown into the Soundblaster is also of very poor quality. Thus, if you plug a standard stereo mic into this input it will pick up sound from one channel and feed the other with 5 V DC. Plugging in a mic with a mono plug will give noisy recordings and maybe short-circuit the 5 V DC in the Soundblaster as well.
Now repeat after me: The mic input in a Soundblaster sound card is not to be used for recording.
regards, Nils