(d)
A Monitor track Level Control (general purpose attenuator) calibrated
0 to –40dB and off
(e)
An Amplifier B.
(f)
An Amplifier C2.
(g)
A Pan Pot.
(h)
Two Amplifiers B feeding output bus lines. These lines are paralleled
in pairs within the cassette and the pairs are paralleled in the track
monitor cassette socket of the main cableform.
6.5
Echo Channels
6.5.1 Echo Send
In order to be able to add to a monitor channel echo which is not recorded, a
tapping is taken from the output of the monitor track level control and fed through
the following:
(a)
An Amplifier G.
(b)
An echo level control (general purpose attenuator) calibrated 0 to –
40dB and “off”.
(c)
An Amplifier B.
(d)
An echo channel selector as used in the Microphone cassette which
can select any of the four echo bus lines.
6.5.2 Echo Return
A Microphone channel is used for echo return and, as described in 3.5.8 this
can be switched to certain monitor channels. The point of return is the virtual earth
input of the Amplifier C2. Connection is made to this point through a 47
Ω
resistor,
which prevents parasitic oscillation.
6.6
Power Supply
The power supply is identical with that used in the microphone cassette (see
3.9). A Track Monitor Cassette consumes about 36mA at +20V and 59mA at –20V
7.
CONTROL ROOM MONITOR CASSETTE
7.1
Function
This cassette contains the record/replay switching and provides the controls
for the control room monitor loudspeakers including signal selection, level, poling,
muting and quieting. It also contains the correlator switching and circuitry, the
provision for sending synchronous replay to cue, the cue line output circuitry and the
buzzer and red light buttons.
7.2
Loudspeaker Channel
7.2.1 Input Key
A single key K2 is used for both channels to select either the multi-track bus
bars or the auxiliary stereo bus bars.
