Altec Lansing 1707C - Mixer;Power Amplifier Operation; Rear-Panel Control and Connectors; Operating the 1707 C;1715 C Mixer;Power Amplifiers

Figure 15 below displays the rear panel on the 1707C mixer/power amplifier with numbers that point
out each connector or control. You can find the corresponding number and name/description of each
connector or control in the text below Figure 15. These connectors and controls are identical on the
1715C.
Figure 15. Rear-Panel Control and Connectors for the 1707C
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N x i
Permits access to the screwdriver adjustable controls
on the modules.
Access Holes
Covers connector mounting holes. Protects against
internal voltages when not using port and connector.
Blank Cover Panel
Combine two units together by connecting LINK OUT
of system one to LINK IN of system two. This is an
RCA-type phono connector.
LINK OUT Connector
Provides a direct input to the amplifier. This is an RCA-
type phono connector (ref. 1 kHz, 100 mvrms).
LINK IN Connector
PREAMP OUT Connector
Use to patch auxiliary equipment between unit's mixer
and power amplifier. PREAMP OUT is normally strapped
to AMP IN. The PREAMP OUT connector precedes the
front-panel MASTER level control. This is an RCA-type
phono connector.
AMP IN Connector Provides a direct input to the amplifier. This is an RCA-
type phono connector (ref. 1 kHz, .775 mvrms).
Provides an auxiliary output of the signal appearing
at the amplifier's input. This is an RCA-type phono
connector.
AUX OUT Connector
Permits connection of external switches to operate
the system's mute and tone generator circuits.
Seven-Lug Screw Terminal
Connector.
OUTPUT LEVEL Control
Increase the output level of the tone generator by
rotating the screwdriver-slotted control shaft
clockwise. To decrease the output level, rotate it
counterclockwise.
Permits connection of various loads to the
amplifier.
Seven-Terminal Barrier
Strip Connector
U Shorting Strip
Connects output of amplifier to input of output
transformer. When in place, use only the transformer
outputs.
Protects load against excessive current from
amplifier. Replace only with the same fuse type
and power rating.
OUTPUT FUSE
Battery Input Connector Use to power system from battery supply for auxiliary
operation or standby switchover. Requires one +48V DC
battery power source, 1.5 amps maximum for the
1707C and 3 amps for ihe 1715C.
Protects against excessive current drain from an
alternating current source. Replace only with same
fuse type and power rating.
14 AC FUSE
The ground terminal lets you connect auxiliary
equipment to the mainframe.
15 GND
11
NOTE
The LED display precedes each front-
panel input-level control. As a result,
it will always indicate the nominal and
peak levels regardless of input channel
settings. Please refer to the mainframe
block diagram shown in Figure 7.
Once the gain is set for each input module
channel, rotate the front-panel input-level
channel controls (CH 1-6) on the mixer/
power amplifier to their 12:00 o clock
(MID) position. Slowly increase the MAS-
TER output level control on the front of
the mainframe until you hear a normal
operating level through the loudspeaker
system. Then readjust the input-level
channel controls slightly for the destred
mix or blend of signals.
. Adjust the high-cut (HF) and low-cut (LF)
filters on the input module as needed for
the desired response. The widest possible
bandwidth occurs when you rotate both of
these controls to the FLAT position. This
is the best setting for music. However, in
speech-only channels, you should limit
the bandwidth to help reduce noise and
system feedback.
. To use the mixer/power amplifier's output
tone-control section, move the two-posi-
tion EQ IN/DEFEAT slide switch to the
EQ IN position. Then adjust the BASS
and TREBLE controls for the desired re-
sponse. From a center or 12:00 o'clock
(MID) position, rotate either control clock-
wise to boost response or counterclock-
wise to cut response.
If using the tone-control section is inap-
propriate for current applications, such as
Acousta-Voicing, move the EQ IN/DE-
FEAT slide switch to the DEFEAT position.
This disconnects the BASS and TREBLE
controls.
To use the compressor/limiter section,
follow this procedure:
Move the slide ON/OFF switch to the ON
position.
Rotate the RELEASE TIME control to its
maximum position (full clockwise).
Rotate the COMPRESSION RATIO con-
trol to minimum position (full counter-
clockwise).
Rotate the THRESHOLD control to its
12:00 o'clock (MID) position.
Begin increasing the compressor/limiter
bv rotating the COMPRESSION RATIO
control clockwise until vou achieve the
desired amount of compression or limiting.
Since the amount of compression or
limiting depends on the incoming signal
level, you may need to readjust the
THRESHOLD control. To lower the trig-
gering threshold, rotate the THRESHOLD
control counterclockwise. If the system re-
quires a higher incoming signal level to
trigger the compressor/limiter, raise the
threshold bv rotating the THRESHOLD
control clockwise.