Plugging a microphone into a guitar amp using a guitar input is a very bad bad idea.
This is because the voltage put out by the microphone is much too low for the input on the amp.
Mics put out Lo Z signal and Guitars put out Hi Z signal,
You need to plug the mic in to a Mic level (not line level) input on your sound card.
Or use a preamp.
Line level will also overload the guitar amps input.
My guess is that the computer is not set up properly.
page and www.studiotrax.net
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