Crest Audio CKS, Owner'S Manual

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Crest Audio CK Power Processing Amplifiers Page 5
PowerSave.
All CK Power Processing amplifiers come standard with PowerSave
circuitry. This effectively reduces current draw and thermal emis-
sions to a minimum when the amplifier is at idle. PowerSave oper-
ates by cutting off the bias current to the output stage after signal
absence is sensed at the input. Once signal is present, PowerSave
instantly restores the bias current after the first positive-going wave-
form. Current draw specifications while PowerSave is active are
included in specifications under "Idle Current Draw."
Thermal Emissions.
System cooling needs must be considered before installation, and the
system installer/designer should specify appropriate countermea-
sures, such as ventilation, air conditioning, etc. Refer to the specifi-
cations appendix at the back of this manual for specific thermal
emissions figures.
Mode Configuration.
CK Power Processing amplifiers are configured standard for two
channel (stereo) operation. They can, however, be wired to operate
in bridged mono mode (a single Mono input amplified to the com-
bined power of both channels and made available as a single Mono
output) or parallel mode (where a single Mono input signal is fed to
both channels).
Two Channel (Stereo) Mode.
In the factory configured, standard two channel (stereo) mode, both
channels operate independently, individual input attenuators control-
ling their respective levels. Signal at Channel A’s input produces
output at Channel A’s output, while signal at Channel B’s input pro-
duces output at Channel B’s output. (Recommended minimum nomi-
nal load impedance for stereo operation of CKS Series amplifiers is
4 ohms per channel; 2 ohms per channel for models CKS 800-2,
1200-2, and 1600-2. CKV and CKX Series amplifiers are specifical-
ly designed for use with distributed or constant voltage systems. See
appendix E for information on recommended distributed line imped-
ance.). Connect loudspeakers to the barrier strip output connectors
for channels A and B. Connections are shown in the diagram below.
Parallel Mode.
To send the same signal to both channels, connect the input signal to
Channel A via the Input Barrier Strip. Run jumpers from the positive
and negative terminals of Channel A’s Input Barrier Strip to the
respective terminals of Channel B’s. Both channels then share
Channel A’s input signal, but will operate independently. Speakers
are connected as in Stereo Mode.
Bridged Mono Mode - CKS Series Power Amplifiers.
Bridged Mono Mode straps both amplifier channels together, making
a very powerful single channel amplifier. One channel “pushes” and
the other “pulls” equally, effectively quadrupling the power over that
of either channel alone. Signal is connected to the input barrier strip
as shown in the drawing below, with one jumper connecting the pos-
itive (+) terminal of Input A to the negative (-) terminal of Input B,
and another jumper connecting the negative (-) terminal of Input A
to the positive (+) terminal of Input B. Both channel attenuators
(A&B) are used to control signal level, and both must at the same
level, preferably at 0dB attenuation. The speakers are connected only
to the designated “+” output terminals as shown below.
Note: Use extreme caution when operating in bridged mono mode.
Never ground either side of the speaker cable when the amplifier is
in bridged mono mode; both sides are “hot.” If an output patch
panel is used, all connections must be isolated from each other and
from the panel. For CKS Series amplifiers, the recommended mini-
mum nominal load impedance in bridged mono mode is 8 ohms, the
equivalent to driving both channels at 4 ohms. [For models CKS
800-2, 1200-2 and 1600-2, the recommended minimum nominal load
impedance in the bridged mono mode is 4 ohms, equivalent to dri-
ving both channels at 2 ohms].
Note: Driving loads of less than the recommended minimums will
activate the IGM circuitry, resulting in a loss of power, and may also
cause a thermal protect condition.
LISTED 8B42
COMMERCIAL
POWER
AMPLIFIER
120V~60 Hz 15A
Com
Out
In
+8 to 18VDC
20 mA
CLASS 2 WIRING
MAY BE USED
Output
A
B
+
+
–
–
Signal
Ground
Lift
Jumper
Input A Input B
+ + – –
7
8
9
5
2
0
1
3
4
6
10
7
8
9
5
2
0
1
3
4
6
10
Model
CC-IPB
Level
B
Level
A
NEC
CLASS 2 ONLY
Model
CC-STL
- +
- +
+ - + -
LISTED 8B42
COMMERCIAL
POWER
AMPLIFIER
120V~60 Hz 15A
Com
Out
In
+8 to 18VDC
20 mA
CLASS 2 WIRING
MAY BE USED
Output
A
B
+
+
–
–
Signal
Ground
Lift
Jumper
Input A Input B
+ + – –
7
8
9
5
2
0
1
3
4
6
10
7
8
9
5
2
0
1
3
4
6
10
Model
CC-IPB
Level
B
Level
A
NEC
CLASS 2 ONLY
Model
CC-STL
- +
- +
+ -
LISTED 8B42
COMMERCIAL
POWER
AMPLIFIER
120V~60 Hz 15A
- +
NEC
CLASS 2 ONLY
Com
Out
In
+8 to 18VDC
20 mA
CLASS 2 WIRING
MAY BE USED
Output
A
B
+
+
–
–
Signal
Ground
Lift
Jumper
Input A Input B
+ +
– –
7
8
9
5
2
0
1
3
4
6
10
7
8
9
5
2
0
1
3
4 6
10
Model
CC-IPB
Level
B
Level
A
+ -
Ch.A
Model
CC-STL
Parallel Mode Diagram
Stereo Mode Connection Diagram
Bridged Mono Mode Connection Diagram.
CKV and CKX Series amplifiers can also be
wired for Bridged Mono mode operation.
However, bridging these models is usually unde-
sirable, as the resultant output will be approxi-
mately 140V (CKV) or 200V (CKX)! There are,
however, specific applications for this configura-
tion. Contact Crest Audio Customer Service for
more information if required.
Regardless of operating mode, NEVER
connect amplifier outputs together!
Bridged Mono Mode - CKV & CKX Series.