Editing Mixing console (section)

====Basic input controls====
The first knob at the top of an input strip is typically a ''trim'' or ''[[Gain (electronics)|gain]]'' control.  The input/preamp conditions the signal from the external device and this controls the amount of amplification or [[attenuation]] that is applied to the input signal to bring it to a [[nominal level]] for processing. Due to the high gains involved (around +50 [[decibel|dB]], for a microphone), this stage is where most noise and interference is picked up.  [[Balanced]] inputs and connectors, such as XLR or phone connectors that have been specifically wired as balanced lines, reduce interference problems.

A microphone plugged directly into a [[power amplifier]] would not produce an adequate signal level to drive loudspeakers, because the microphone's signal is too weak; the microphone signal needs a [[preamplifier]] to strengthen the signal so that it is strong enough for the power amplifier. For some very strong [[line level]] signals, the signal that is plugged into the mixer may be too strong, and cause [[audio clipping]]. For signals that are too strong, a 15&nbsp;dB or 20&nbsp;dB [[Attenuator (electronics)|pad]] can be used to attenuate the signal. Both preamplifiers and pads, and the controls associated with them, are available in the input section of most mixing consoles.

Audio engineers typically aim at achieving a good ''gain structure'' for each channel. To obtain a good gain structure, engineers usually raise the gain as high as they can before [[audio clipping]] results; this helps to provide the best [[signal-to-noise ratio]].

A mixing console may provide [[Insert (effects processing)|insert]] points after the input gain stage. These provide send and return connections for external processors that only affect an individual channel's signal. Effects that operate on multiple channels connect to auxiliary sends (below).