ABSTRACT
Microphones are called as a general class transducers, changing acoustical energy, sound, into electrical energy, voltage. They typically put out much lower voltage levels than most audio gear, so they must be amplified by a microphone preamplifier to get to usable levels. A typical amount of voltage delivered by a professional microphone is 13 mV (0.013 V), a rather small voltage, for 94 dB SPL,1 a rather loud level. Thus, microphones must be connected to microphone inputs, and the converse is true too: line-level devices like CD players must be connected to line-level inputs. If a linelevel device is connected to a microphone input, the result will typically be overload or bad distortion. If a microphone is connected to a line-level input and the gain is raised high to hear it at all, the result will typically be noisy or hissy. This is complicated by themicrophone attenuate (MICATT) switch on some cameras that allows high-level microphone outputs (when encountering loud sound) to be accommodated by low-level (sensitive) microphone inputs.
