Amplifiers
Audio signals spend most of their time as very light distortions in an electrical current, which can be passed through diaphragms to transmit the current into small pressure changes the flutter the diaphragm, much like our eardrum (although diaphragms work in reverse to, and record sound by moving to incoming pressure waves and translating that movement into an electrical current. As this signal passes between current (or in optic systems, light) and diaphragms, it preserves all the audio information. How well the signal is preserved is directly related to how clear the sound is when it is produced by speakers.
However, the signal has problem: in order to make the necessary pressure waves (sound), it has to move much larger diaphragms in the speakers. This is where amplifiers come in. An amp takes the signal and makes it large, stronger, exaggerating its characteristics. The most complex amps include a large amount of electrical circuitry, all devoted to ensuring the signal is expanding as neatly as possible, leaving its quality intact while making it strong enough to emit sound through speakers. Many amps boost the signal several different times, making it more powerful in stages.
Stereos and Monoblocks
Most large amps are stereo version--in other words, they operate on two different channels. Two different input signals are sent and received, so that two different sound streams are amplified for two different speaker systems. This allows for a wide variety of sound effects, allowing a slightly different sound from one speaker than the other, and allowing sounds to switch back and forth between speaker systems. Stereo amps are also capable of creating a third signal that is the sum of the first two signals.
Monoblock Process
Monoblock amps take this same idea and separates its out, giving one amplifier systems for one channel and another, separate amplifier system for the other channel. This means more room is needed for the two separate amps, and the entire systems costs more, but there are also several advantages, especially for audiophiles. First, there is less "cross talk" between the signals, or distortion caused by the propagation the two channel signals throughout the system. In a stereo system it is much easier for the signals to interfere with each other, causing sound quality problems.
Also, when the stereo signal is separated into two different systems, both systems can have a higher-rated power flow. While actual current values do not necessarily change, the power does not need to split between two different channels on the same system, and the pure focus of the power supply can lead to better sound quality.
Tags: different channels, different sound, electrical current, pressure waves, sound quality