Nagra III - Volume Controls and Output Sockets

Page 4
The automatic record position is useable for speech but not for music.
The automatic facility only affects the microphone channel and not the line
input.
PLAYBACK & BATT. METER to the left = Play-back on the internal
loudspeaker. In this position the meter indicates the battery voltage. The
play-back level is varied by the "line input and playback" volume control.
The headphones are fed directly from the play- back amplifier at an
uncontrolled level. The quality through the loudspeaker or at the line output
is not high. On the other hand the monitoring output for headphones is always
fed with a high quality signal.
HI-FI PLAYBACK = Normal high quality play-back.
The loudspeaker is out of circuit and the signal output is fed at low level for
headphones at the monitoring output and at high level to the line output sockets.
The signal fed into the line is measured by the meter. This output consists
not only of the signal play-back from the tape and adjusted by the control
"line input and play- back" but also a signal from the microphone can be added
for a commentary. The level of this signal is controlled by the mike input
potentiometer. When this facility is not required the mike input potentiometer
must be turned fully anticlockwise when replaying a normally recorded tape.
To play back a normally recorded tape, the "line input and play- backll control
should be turned to the indication 0 db. This will produce a normal signal to
the line. If it is necessary to vary this control to have a normal signal to the
line, it is an indication that the recording has not been made at normal level.
This is a useful facility for checking a recording.
10) Microphone Input Level Control
This control varies the modulation level of the signal, which is fed into the
microphone input.
11) Zero Level Reference Signal Push Button
This push button, sends a whistle through the line input while the recorder
is running. It is useful to record this whistle before recording sound at a
zero level, that is to say, the modulometer needle should point to zero on
the scale. This signal is highly useful for the regulation of the chain of sound
transfer. It is as well to leave at least two complete turns of the tape between
the signal and the sound track so as to avoid the possibility that it might be
superimposed on the sound track during the transfer process.
12) Line Input and Play-back Volume Control
This control has two purposes:
a) During Hi- Fi recording it varies the modulation level of the signal fed
into line input.
b) During play- back it varies the signal output.
13) Monitoring Output Sockets
These sockets are suitable for headphones, with an optimum impedance of
50 ohms. Any other impedance value will only result in a reduced level.
It is preferable to use electrodynamic headphones of high quality.
In operation this output is taken from: