2.4.9 Echo Circuits
Each microphone channel has an echo send level control and a switch
whereby a signal, which is tapped off after the fader, can be routed to any of four
echo lines.
Solely for convenience, and not because there is any association, the echo
output circuits are located in the Group Cassettes, two output circuits being included
in each Group Cassette. Thus if three or four echo output circuits are required, the
mixer must have two Group Cassettes. Switching is provided whereby the echo
output level may be observed on the VU meters.
A normal microphone channel is used for each echo return and the signal,
suitably controlled, can be fed to any track or pair of tracks. If it is required to record
without echo but to listen with echo on the monitor speakers, signal from the
channels in the Track Monitor Cassette can be fed to the echo bus lines and the
output of any microphone channel used as an echo return can be switched so that it
is injected into the required channel. A total of eight inject lines is available. If the
mixer provides for eight track recording plus auxiliary stereo, six of the inject lines
connect to the monitor channels associated with the first six of the eight tracks, and
the remaining two, Nos. 4A and 4B connect to the auxiliary stereo monitor channels
5A and 5B.
2.4.10 Cue Circuits
Two cue circuits are provided. Signal from any microphone channel is tapped
off prior to the fader and fed through a level control to a switch whereby it can be fed
to either of the two cue bus lines, or both of them simultaneously without introducing
cross talk. Signal from each main channel circuit can also be fed to either or both of
the cue bus lines, in this case separate level controls being provided.
Main cue level controls and line output amplifiers are provided in the Control
Room Monitor Cassette, switching being provided whereby the output level may be
observed on the VU meters. This cassette also contains level controls whereby two
synchronous replay signals, designated left and right, which are routed through the
Studio Playback Cassette, can be fed to the cue circuits, left to cue 1 and right to
cue 2. The synchronous replay signals and the cue bus signals are available on the
input selector switches of the Control Room Monitor and Studio Playback Cassette
so that any of these signals can be fed to the control room or studio loudspeakers.
The zero level cue signals from the Control Room Monitor Cassette are fed
to small power amplifiers located in the main power unit. These will provide a very
loud signal for up to six pairs of 50
Ω
headphones in parallel or will operate a small
8
Ω
loudspeaker. A selector switch and two level controls are provided to enable the
Artist Manager to communicate through the cue circuits. The Operator has a key
switch, which connects the output from his microphone through separate pre-set
level controls to both cue circuits.
