That is a microphone preamplifier. Scroll down to related links and look at "How to Make Sense out of the Mic Preamp Jungle".
No, really not.
Yes, you definitely can.
get a freaking microphone. get a karaoke or amp machine and plug the microphone in. Sing. That's all for today. (:)(:(
microphone
Through the MIDI (Musical Instruments Digital Interface) port.
anything with a 1/4in female jack
Certainly.... so long as the microphone has the appropriate connector.
Yes, it is an instrument for recording. A microphone is a sensor device that converts mechanical pressure waves or sound in air into electrical voltage waves. Speaking into a microphone excites (moves) a diaphragm that is coupled to a device that creates an electrical voltage proportional to the produced sound pressure.
It's called feedback. The microphone causes a loop, what is coming out if the amp is being asorbed by the mic, sent back to the amp and projected again. The loop causes a squeal.
You didn't plug the cord in all the way. It may not be the actual microphone. On occasions the socket of the amplifier can short out (connection break). It would be wise to test your mics on another persons amp to see it they work there - this will give you a guide back to a faulty amp.
An LM741 is what is known as an "Operational Amplifier", or "Op-Amp" for short. Op-Amps are arguably one of the most useful electronic devices, with almost any electronic device containing at least one in some form or another. Exactly what an Op-Amp does depends on the circuit it is in, however in general, an Op-Amp takes an input signal and boots it up to a higher level. One application would be a microphone pre-amp, where an Op-Amp would take the low-voltage input from the microphone and boot it up to a level that the power amp can use.
A microphone preamp's output may be XLR or 1/4". You will need a cable that will adapt that output to a 1/8" stereo plug for the line input of your computer.