A description of the technology and function of the pad (attenuator) as found in mixing consoles.
The mic preamp (preamplifer) is where the input signal is conditioned so that it is suitable for further processing in the console.
In some mixing consoles and mic preamps, the lowest gain setting is insufficiently low to cope with very high output levels from the microphone.
In this case there will probably be a ‘pad’ switch. A pad is an attenuator – it makes the signal smaller. Think of it as a Passive Attenuation Device.
Usually, a mixing console pad reduces the signal level by 20 dB. An external pad will mostly likely be 10 dB or 20 dB.
In a well-designed console, the pad should be positioned before the active circuit components. This means that, when active, the pad cuts down the signal level before it has the chance to cause any distortion.
Another reason to use the pad is if it is found that the fader on that channel is inconveniently low. When the fader is low down, it is difficult to adjust accurately.
So if you need to have precise control over a signal that is only required at a low level in the mix, it is handy to use the pad to allow the fader to be placed higher up in its range.