Pre-amplifiers
The role of the preamplifier is to adapt the source signal before it is amplified by the power stages. As the first stage of amplification, it is the key to a good signal-to-noise ratio. Indeed, the more a signal is weak in intensity, the more it is sensitive to interference. It is this point in particular that will make the difference between a good and a bad preamp.
That said, the goal of separating the main power stages and preamplification becomes explicit: to limit the interference between the high level and the low level.
In addition to that, some preamps will have a built-in DAC, a balance management, a frequency filter or a CD player.
