You can purchase an XLR microphone at Best in Music, Radio Shack, Fry's Electronics and many local electronics stores as well as music stores. Some super stores such as Wal-Mart might carry them as well.
It is used to connect microphone to microphone preamplifiers.
Between microphone and microphone preamplifier
It is a microphone cable
It is a XLR microphone connector that has holes instead of pins
Any microphone with XLR input
To connect microphones to microphone preamplifiers
XLR is a type of audio connector used in professional audio and video equipment. The three pin XLR is used universally for microphone and single channel audio signals. An XLR adapter is used to connect a professional audio signal to an alternative format. On a camcorder, it might be used to connect a low cost microphone or radio microphone receiver to the XLR input on the camera. One might be used on the audio output of the camcorder to connect to a domestic audio input that uses phono or RCA connectors.
The better microphones use XLR-plugs as connection.
Yes, although you will need a sound card to capture the XLR signal from the microphone.
From a music store.
The only requirement for a microphone is that the cord type (XLR, 1/4") matches your machine's inputs.
You can purchase XLR to RCA connectors from the Guitar Center website. Alternatively, you can purchase these connectors online from the Amazon website.