control (labelled KEY) grouped with the OP and AM pre-sets and which has a range
from about 3dB to 23dB. On each side of the loudspeaker quiet key is a spring
return push button which mutes the corresponding channel.
7.2.10 Loudspeaker Line Output
Each channel has an Amplifier R and an output transformer as used for all
other line outputs. A 5-pin Tuchel Socket is provided for connection of the
loudspeaker amplifier leads.
7.3
Record/Replay Switching
7.3.1 Tape Replay Selection
Grouped with the input key are the three tape machine selection keys
referred to in 6.4.1.
7.3.2 Record/Replay
This is a 12-pole change over key of which only 10 poles are actually used,
eight for 8-track working and two for auxiliary stereo for switching the monitor loud
speakers. In the record position, signal is received from the outputs of Amplifiers G
in the Main Cassettes (see section 5.5.3). In the replay position signal is received
from the tape machine selection keys (see 7.3.1). The movers of this key are
connected to the monitor channel inputs in the Track Monitor Cassettes (see 6.4.2)
and also to the follow contacts of the follow/replay key.
7.3.3 Follow/Replay
This also uses 10-poles of a 12-pole change over key. Its fixed contacts
connect to the movers and replay contacts of the record/replay key and its movers
connect to the record/replay contacts on the V.U. Meter selector switches in the
Main Cassettes (see 5.3.3). It thus enables the V.U. Meters either to follow the
changes of the record/replay key or to be left on replay.
7.4
Correlator
7.4.1 Correlator Switch
This is a 2-pole 8-position switch, the positions being marked Off, Mon., 1, 2,
3, 4, 5 & 6. The two poles handle the two inputs of the Correlator. In the “off”
position these are connected to the 0V line. In the Mon. position they derive signal
from the special outputs of the Amplifier J (section 7.2.8). In positions 1 to 6 the
switch is wired to the movers of the follow/replay key so that in positions 1 to 5 the
correlator meter indicates the correlation between the signals on the two V.U.
Meters associated with Main Cassettes Nos. 1 to 5 respectively. Since the signal is
taken from the output side of the follow/replay key, the indication can be switched to
record or replay by the record/replay key if the follow/replay key is set to follow. In
order to prevent the shorting together of two channels when the switch is operated,
series resistors are connected in series with alternate studs within the switch.
