Altec Lansing 1715C - Manual (Page 14)

when signal levels are high enough to cause
significant output clipping.
A dual slope V-l limiter protects the output
devices. It keeps the output devices operating
within their SOA (safe operating area) as de­
fined by the device manufacturer.
A special integrated circuit function block
monitors the heatsink temperature, power-
supply voltage, and the amplifier’s output
When it detects a problem, it immediately
disengages the output relay.
Output Connections
Make output connections to the seven-ter­
minal barrier strip connector located on the
lower-left side of the mainframe's rear panel.
The 1707C main output connections include
an 8 Q direct output (24.5 vrms) and three
transformer balanced outputs; 4 Q (17.4
vrms), 25 vrms (8.3 Q), and 70.7 vrms (66.6 Q).
The 1715C main output connections include a
4 £2 direct output (24.5 vrms) and a 25 vrms
(4.2 Q), an 8
Q (34.6 vrms), and a 70.7 vrms
(33.3 Q ) balanced transformer output.
Refer to Figure 8 for a display of the direct
output connections and Figure 9 to see the
transformer output connections.
OT an
70V 2SV 4/1
COM
IN -f~ -
R«mov« shorting bar ^ ^ | l_
Figure 8. Direct Output Connections
OT an
70V 25V
4H COM
IN -F -
T T •
I 1 , .L_, i , : i.._ j
Insert shorting C
the unit. If the fuse continues to blow, check
the load to see if it shorted or is exceeding
the rated power consumption. If the problem
continues, have a qualified service technician
service the unit.
Mute/Tone Generator Connections
The seven-lug screw terminal connector lo­
cated on the mid-left rear of the mainframe
provides access to the system mute and tone
generator. For connection details, refer to
Figure 10.
MUTE S/T BUZZER
COM COM R/T YELP
o o o o o o o
rrrTTTl
Table III. Maximum Allowable Cable Resis­
tances
Function Resistance
O
S/T Chime 13 kO
R/T Chime 15.8 kO
Buzzer 8 kQ
Yelp 8 kO
Mute 8 kQ
External SPST switches
(not included with mainframe)
Figure 10. Mute/Tone Generator Switch
Connections
A switch closure between the mute and
common (COM) terminals will mute any input
modules configured in the s/ave mode. You
can use the remaining switches to select one
of the following sounds:
A single-tone chime (S/T),
A repeating-tone chime (R/T),
A buzzer, or
A yelp (siren).
For the duration of a tone, the tone generator
automatically mutes any input modules con­
figured in the slave mode.
Output-Level Control: The tone generator's
output-level control is conveniently located
on the rear panel of the mainframe. To in­
crease the tone generator’s output level, rotate
the screwdriver-slotted control shaft clock­
wise.
LINK IN/LINK OUT Connections
The LINK IN/LINK OUT phono connectors on
the mid-rear panel of the mainframe permit
you to dynamically
link two or more systems
together. If you require more channels, the
1707C/1715C mixer/power amplifiers are fully
compatible with 1700C mixer/preamplifier. For
more information on the 1700C mixer/
preamplifier, you may order the operating
instruction manual (P/N 42-02-029241) or the
specification sheet (P/N 42-07-029242) from
our Order Entry Department.
The signal appearing at the LINK OUT con­
nector is the summation of all input channels
as mixed by the input channel level controls.
LINK IN is a direct input to a system’s mixing
amplifier; it’s also a seventh Input channel.
To link two units together, connect LINK OUT
of system one to LINK IN of system two. Sys­
tem two will now control the mix of up to
twelve input channels. Please referto Figure
11 for typical linking connections.
-NOTE
The LINK OUT signal is not affected by
the compressor/limiter or the E.Q. cir­
cuits.
Figure 9. Transformer Output Connections
To use a transformer balanced output, install
a
U shorting bar between the direct (-L) out­
put and the output transformer’s input (OT IN).
-------------------------NOTE--------------------------
When using the output transformer, you
may use any combination of output
connections as long as the total con­
nected load does not consume more
than 75 watts for the 1707C or 150
watts for the 1715C.
Output Fuse: A fuse in series with the output
of the amplifier section protects the amplifier
from excessive current consumption by a
load. If this output fuse blows, replace it only
with a fuse that matches the same type and
rating as silkscreened on the rear panel of
------------------------- NOTE---------------------------
Optional External Mute, (connected at
the factory) allows external muting of
the tone generator. If disconnected,
the tone generator cannot be extern­
ally muted.
Resistance Effects of Long-Cable Runs on
Mute/Tone Generator Circuits:
Table III shows
the maximum allowable cable resistance (total
resistance) that the mixer/power amplifier
can support. Resistances greater than these
values, resulting from excessively long-cable
runs or small gauge wire, may cause the mute
or tone generator circuitry to fail to operate.
Please make sure all cable resistances are
less than the values shown in Table III.
PREAMP OUT/AMP IN Connections
The PREAMP OUT signal is a mix of all input
channels processed by the compressor/limiter
and tone control circuits. Normally, you would
insert a
U shorting bar between the PREAMP
OUT and AMP IN phono connectors on the
rear panel. However, you can remove the
shorting bar to patch in an external equalizer
or other signal processing device with a pro­
per level match of 0.775 vrms nominal. Figure
12 shows a typical application using an ex­
ternal equalizer or other signal processing
device.
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