A recording console has two types of signal source. One is from the microphone
and line inputs. The other is from the already-recorded signals on the multitrack
tape. To record overdubs, these must be mixed together for the monitor mix and
The simplest way to arrange this is to have a console with many inputs – at
least the number of tracks on the multitrack (often up to 48), plus the number
of microphones you need to use simultaneously. A total of 72 channels would
suit most applications.
In this example of a 72-channel console, 24 channels can be dedicated to inputs,
the other 48 channels can be used for monitoring the already-recorded signals
on the multitrack recorder.
This 'all input' architecture is easy to understand and operate, but it requires
a lot of channels.
There have been a number of consoles designed specifically in this format,
notable by Amek and Soundcraft. However, any console with sufficient channels
can be used this way.
Since all-input is so easy to understand and use, many engineers work this
way, even on an inline console.