Recording Consoles 777tended to provide an entirely separate mixer (usually to the right of the group and main
faders) devoted to dealing with the return signals. Such a mixer architecture is known
as a split console. The alternative approach, which is now very widespread, is known
as the in-line console, so named because the tape-return controls are embedded within
each channel strip, in line with the main fader. This is the type of console considered in
detail later. From an electronic point of view, very little difference exists between these
approaches; the difference is more one of operational philosophy and ergonomics.
Both the split and in-line console are yet another example of a “ mixer within a mixer. ” In
effect, in the in-line console, the tape returns feed an entirely separate mixer so that each
tape return signal travels via a separate fader (sometimes linear, sometimes rotary) and pan
control before being summed on an ancillary stereo mix bus known as the monitor bus.
The channel input strip of an in-line console is illustrated in Figure 27.9. The monitor bus
is exceptionally important in a recording console because it is the output of this stereo mix
amplifi er that supplies the signal that is fed to the control room power amplifi er during
the tracking phase of the recording process. (Usually, control room outputs are explicitly
provided on the rear panels of a recording console for this purpose.) The architecture is
illustrated in Figure 27.10. During mixdown, the engineer will want to operate using the
main faders and pan controls, because these are the most operationally convenient controls,
being closest to the mixer edge nearest the operator. To this end, the in-line console includes
the ability to switch the tape returns back through the main input strip signal path, an
operation known as “ fl ipping ” the faders. The circuitry for this is illustrated in Figure 27.11.
27.5.8 Talkback
Talkback exists so that people in the control room are able to communicate with performers
in the studio. So as to avoid sound “ spill ” from the loudspeaker into open microphones
(as well as to minimize the risk of howl-round), performers inside the studio invariably
wear headphones and therefore need a devoted signal that may be amplifi ed and fed to
special headphone amplifi ers. In the majority of instances this signal is identical to the
signal required in the control room during recording (i.e., the monitor bus). In addition, a
microphone amplifi er is usually provided within the desk, which is summed with the monitor
bus signal and fed to the studio headphone amplifi ers. This microphone amplifi er is usually
energized by a momentary switch to allow the producer or engineer to communicate with the
singer or instrumentalist, but which cannot, thereby, be left open, thus distracting the singer
or allowing them to hear a comment in the control room that may do nothing for their ego!