Output voltage of the microphone is often measured in units, sometimes tens of millivolts. Therefore, this signal is very weak, besides its quality deteriorates during transmission over long cables. Is virtually impossible connect to multiple consoles one microphone, while receiving a good sound. Let's imagine this situation: is the task of voice concert at the stadium, where the length of the Multi is 100 meters, and acting requires a monitor console. In this situation, it is recommended to use separate mic preamps (rack preamps). By acquiring multiple rack preamps, you'll see that getting rid of the set minor problems.
At first the mic preamps are an ordinary microphone amplifier. It has a low impedance balanced input with adjustable sensitivity and the possibility of phantom power + 48 V for condenser microphone. Linear preusilitel with adjustable gain (2) has unbalanced high impedance (100 ohms to 1 megohm) input, which serves both impedance converter (Di-box), which allows you to connect to it Pickup tools, including piezoelectric transducers from guitars, pianos, etc. The combination of these two provides the opportunity to work with any source of signals. In the above case, instead of In order to take away a weak signal length by various mixing consoles, you can connect a microphone is much shorter wire to the preamplifier, which stands on the stage.
If this all turns out excellent clean sound, not eaten by long cables. From the stage to a mixing console with a powerful signal to go out, so there will be no loss even with a powerful output. A number of independent output enable distribute the signal between multiple users and eliminate their mutual influence. An additional advantage of a separate microphone amplifiers is the use of low-cost, linear mixing consoles without built-in microphone amplifier, because to write modern music with lots of electronic sounds often enough to have a 4.3 mic, with the remaining microphone inputs in more ways the remote does not used, and the money to purchase them are spent in vain. As a result, we get a great sound!