CD
CD P ower Am plifier
Owner ’s M a nua l
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IMPORTANT SAFETY INSTRUCTIONS
WARNING: When using electrical products, basic cautions should always be followed, including the following:
1.
Read these instructions.
2.
3.
4.
5.
6.
7.
8.
Keep these instructions.
Heed all warnings.
Follow all instructions.
Do not use this apparatus near water.
Clean only with a dry cloth.
Do not block any of the ventilation openings. Install in accordance with manufacturer’s instructions.
Do not install near any heat sources such as radiators, heat registers, stoves or other apparatus (including
amplifiers) that produce heat.
9.
Do not defeat the safety purpose of the polarized or grounding-type plug.A polarized plug has two blades with one
wider than the other.A grounding type plug has two blades and a third grounding plug.The wide blade or third
prong is provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for
replacement of the obsolete outlet.
10.
Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the
point they exit from the apparatus.
11.
12.
Only use attachments/accessoriegs provided by the manufacturer.
Use only with a cart, stand, tripod, bracket, or table specified by the manufacturer or sold with the apparatus.When
a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.
13.
14.
Unplug this apparatus during lightning storms or when unused for long periods of time.
Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in
any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the
apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.
15.
Never break off the ground pin.Write for our free booklet “Shock Hazard and Grounding.” Connect only to a power
supply of the type marked on the unit adjacent to the power supply cord.
16.
17.
If this product is to be mounted in an equipment rack, rear support should be provided.
Exposure to extremely high noise levels may cause a permanent hearing loss. Individuals vary considerably in
susceptibility to noise-induced hearing loss, but nearly everyone will lose some hearing if exposed to sufficiently
intense noise for a sufficient time.The U.S. Government’s Occupational and Health Administration (OSHA) has
specified the following permissible noise level exposures:
Duration Per Day In Hours
Sound Level dBA, Slow Response
8
6
90
92
4
95
3
97
2
1 1/2
1
100
102
105
110
115
1/2
1/4 or less
According to OSHA, any exposure in excess of the above permissible limits could result in some hearing loss. Ear plugs or
protectors to the ear canals or over the ears must be worn when operating this amplification system in order to prevent a
permanent hearing loss, if exposure is in excess of the limits as set forth above.To ensure against potentially dangerous
exposure to high sound pressure levels, it is recommended that all persons exposed to equipment capable of producing high
sound pressure levels such as this amplification system be protected by hearing protectors while this unit is in operation.
SAVE THESE INSTRUCTIONS !
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important precautions
Service Information
Save the carton and packing materials!
Should you ever need to ship the unit,
use only the original factory packing.
Do not run the output of any am pli-
fier channel back into another
channel’s input.
1
¡
Do not remove the cover!
Removing the cover will expose you to
potentially dangerous voltages.There are
no user serviceable parts inside.
For replacement packaging, call Crest Audio’s
Customer Service Department directly.
Do not parallel- or series-connect
an am plifier out put wit h any
other am plifier output.
Equipm ent should be serviced by
qualified service personnel when:
Read all docum entation before
operating your equipment. Retain all
documentation for future reference.
2
3
Crest Audio is not responsible for damage
to loudspeakers for any reason.
A. The power supply cord or the plug has
been damaged.
Do not connect the inputs or out-
puts of am plifiers to any other
voltage source: such as a battery,
mains source, or power supply, regard-
less of whether the amplifier is turned
on or off.
Ô
£
Follow all instructions printed on
unit chassis for proper operation.
B. The equipment has been exposed to rain.
C. The equipment does not appear to oper-
ate normally,or exhibits a marked change in
performance.
D. The equipment has been dropped, or the
Never hold a power switch or cir-
cuit breaker in the on-position, if
it won’t stay there by itself!
4
5
enclosure damaged.
Connecting am plifier outputs to
oscilloscopes or other test equip-
ment while the amplifier is in bridged
mono mode may damage both the
amplifier and test equipment!
To obtain service:
contact your nearest Crest Audio
Service Center, Distributor, Dealer,
or Crest Audio at 201.909.8700 USA
tional information.
Do not use the unit if the electrical
power cord is frayed or broken.
The power supply cords should be
routed so that they are not likely to be
walked on or pinched by items placed
upon or against them.
email techserve@crestaudio.com
Do not spill water or other liquids
into or on the unit, or operate the
unit while standing in liquid.
¢
ˆ
This symbol is used to alert
the operator to follow important
procedures and precautions
detailed in documentation.
Always operate the unit with the
AC ground wire connected to the
electrical system ground. Precautions
should be taken so that the means of
grounding of a piece of equipment is not
defeated.
6
Do not block fan int ake or
exhaust ports.
This symbol is used to warn operators
that uninsulated “dangerous voltages”
are present within the equipment enclo-
sure that may pose a risk of electric
shock.
Do not operate equipm ent on a
surface or in an environm ent
which m ay im pede the norm al
flow of air around the unit: such as
a bed, rug, weathersheet, carpet, or
completely enclosed rack.
Dam age caused by connection to
im proper AC voltage is not covered
by any warranty. Mains voltage must be
correct and the same as that printed on
the rear of the unit.
7
8
This equipment conforms to EN55022 Class A. In a
domestic environment this product may cause radio
interference in which case the user may be required to
take adequate measures.
If the unit is used in an extrem ely
dusty or sm oky environm ent: the
unit should be periodically blown free of
foreign matter.
§
Do not ground any hot (red) terminal.
This equipment has been tested and found to comply
with the limits for a Class B digital device pursuant to
part 15 of the FCC Rules.These limits are designed to
provide reasonable protection against harmful interfer-
ence in a residential installation.This equipment gener-
ates, uses and can radiate radio frequency energy and, if
not installed and used in accordance with the instruc-
tions, may cause harmful interference to radio communi-
cations. However, there is no guarantee that interference
will not occur in a particular installation. If this equipment
does cause harmful interference to radio or television
reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to
correct the interference by one or more of the following
measures:
Never connect a hot (red) output to
ground or to another hot (red) output!
Do not use the unit near stoves,
heat registers, radiators, or other
heat producing devices.
¶
ƒ
Power down and disconnect units
from mains voltage before making
connections.
9
0
The power cord of equipm ent
should be unplugged from the out-
let when left unused for a long peri-
od of time.
Do not drive the inputs with a sig-
nal level great er t han t hat
required to enable equipm ent to
reach full output.
*Reorient or relocate the receiving antenna.
*Increase the separation between the equipment and
the receiver.
*Connect the equipment into an outlet on a circuit dif-
ferent from that to which the receiver is connected.
*Consult the dealer or an experienced radio/TV techni-
cian for help.
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table of contents
p.2
how to us e this manual
1
p.3
introduction
p.5
ins tallation
2 unpacking
mounting
cooling and ventilation
powering
maintenance
p.9
fe ature s ove rvie w
3 front panel
rear panel
p.15
ope ration mode s
4 stereo
contents
parallel
bridged
p.17
conne ctions
5
input
output
p.21
s afe ty
6 tourclass protection
precautions
user responsibility
p.25
s e rvice and s upport
support
7
contact us
registration
p.27
s pe cifications
a
b
c
d
appendices
p.28
block diagram
p.29
optional handle ins tallation
p.30
wire gauge charts
p. 1
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how to use this manual
CD owner’s manual
1
conventions
terms
official Crest Audio features and
each indicator or control on the amplifier will appear as: terms
actions
specific actions or selections the user can execute will appear as: actions
tasks
are broken down into steps 1
2
3
warnings
Procedures not to attempt.
a
Issues or hazards to keep in
mind when operating
the equipment.
indicators
What to look for on
®
the equipment display.
Alerts, indicators, or
prompts that may appear.
tips
Preferred methods.
Helpful hints.
Feature insights.
+
see
see—refers to other sections of the manual containing
supplementary information on the current topic or a related issue
note
note—supplementary feature information
p. 2
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introduction
1
welcome
Congratulations on your purchase of a new CD Series professional power amplifier and thank you for your confi-
dence in Crest Audio products. You are among the growing number of audio professionals who have made Crest
Audio one of the world’s leading suppliers of professional and commercial/industrial audio systems.
For your safety, please read the Important Precautions section before installing and operating the amplifier.The Crest
Audio CD Series amplifiers are designed for high operating efficiency and accurate sonic performance across the full
audio bandwidth, even under stressful conditions.
The Crest Audio CD series amplifiers utilize Class D amplifier technology which greatly improves the efficiency of
the amplifier and reduces the power demand from the mains supply.The CD amplifier incorporates a linear power
supply design and are built to uncompromising standards.This, combined with major advances in amplifier technol-
ogy provides for extreme reliability and sonic accuracy for which Crest products are renown.
linear-toroid power supply
A traditional linear power supply is used in the CD Series. Because of the amplifier section’s efficiency, (approx
80%) the transformer does not need to be as big or as heavy.This gives the CD Series an advantage in deliver-
ing more power in a more compact package.
The efficiency of the output stage also gives the power supply the ability to handle heavy-duty cycles without
compromising sonic integrity.
In order to maintain strict quality assurance standards, all Crest Audio power amplifiers are built in our state-of-the-
art USA manufacturing facility. Internal components are the finest available and key sub-assemblies are pre-tested
before final assembly. Each amplifier is “burned in” and thoroughly tested (using precision audio test equipment)
before shipping. In addition, all CD Series amplifiers incorporate Crest’s exclusive TourClass® protection features to
safeguard both internal circuitry and connected loudspeakers.
This proven combination of advanced design,quality construction and comprehensive circuit protection is your guar-
antee of fail-safe reliability. You can depend on consistent, stable performance even when your CD Series amplifier
is subjected to punishing extremes in the most demanding fixed or mobile sound reinforcement applications.
p. 3
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installation
2
/
/
/
/
/
what to do with the shipping carton
proper rack-mounting technique
keeping the amplifier cooled
required AC line voltages
unpacking
mounting
cooling and
ventilation
routine maintenance practices
powering
maintenance
p. 5
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installation
CD owner’s manual
2
unpacking
Please inspect the amplifier carefully immediately after unpacking. If you find any dam-
For replacement
packaging, call Crest
Audio’s
Customer Service
Department directly.
age, notify your supplier/dealer immediately. Only the shipper may file a damage claim
with the carrier for damage incurred during shipping. Be sure to save the carton and
all packing materials for the carrier’s inspection.
+
If the packing materials are in good condition, please save them.
If you ever need to ship the unit anywhere without mounting it in a rack, you should
take advantage of the original factory packing materials in order to avoid unnecessary
damage.
see—service and support
mounting
All CD Series amplifiers mount in standard 19-inch racks and occupy two rack spaces.
Four front-panel mounting holes are provided on each amplifier. Rear mounting ears
give additional support and use of rear supports is highly recommended in all mobile
and touring sound systems. Handles are available as an option (P/N: C32000010).
CD dimensions
front width 19.00"/483mm
front
height
3.47"/
88 mm
rear width 17.12"/435mm
front
height
3.47"/
88mm
2
1
3
2
1
3
depth (from rack rails)16.55"/420mm
rack mount dimensions 16.05” / 407mm
p. 6
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installation
2
cooling and ventilation
CD amplifiers use a forced air cooling system to maintain a low, even operating tem-
perature.
Make certain that there
is enough space around
the front and rear of the
amplifier to allow the
heated air to escape.
When mounting in a rack,
try to avoid using doors
or covers on the front
and rear of the enclosure;
the exhaust air must not
be impeded
a
Air is drawn in by a DC fan on the rear panel, flows through the cooling fins and then
exhausts through the front panel vent.
Heat sink temperature is monitored and controls the variable speed fan. Fan speed
increases only as required, keeping fan noise to a minimum.
Keep this unit 8” from any combustible surface on all sides.
suggestion
In racks with closed backs
allow at least one stan-
dard-rack-space opening
for every four amps.
If the heat sink surpasses its maximum allowed temperature, the thermal protection
circuit will activate and open the output relays allowing the amplifier to cool to a safe
temperature. Normal operation will resume once the amplifier cools to a safe level.
Thermal protect activation only occurs under extreme thermal conditions and is not
part of normal operation.
powering
Unless otherwise specified when ordered, CD amplifiers are supplied factory set to
following voltage options :
Option 1 US domestic
nominal 120Vac 60Hz for rated power output
(safe operating range 100 - 132Vac )
Option 2 export models nominal 230Vac 50Hz for rated power output
(safe operating range 200 - 253Vac )
maintenance
On some CD amplifier models the fan is supplied with a removable foam filter.This fil-
ter should be cleaned periodically with compressed air.
If the amplifier is used in an extremely dusty or smoky environment , the unit should
be periodically blown free ( using compressed air ) of any foreign matter that may have
built up inside the unit.
Users will not need to make any adjustments to the amplifier during its lifetime.There
are no user-serviceable parts or adjustments that require opening the amplifier.
p. 7
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features overview
3
/
/
location of connectors and controls
legend of panel symbols
front panel
rear panel
p. 9
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features overview
CD owner’s manual
3
CD shown
1
2 3 4 5 6 7
8
9
p. 10
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features overview
3
front panel
Rack Mounting Ears
1
Two front-panel mounting holes are provided on each mounting ear.
Channel Level attenuators
2
Two input attenuators adjust level for their respective amplifier
channels in stereo and in parallel modes. In Bridged Mono mode, the
channel A attenuator controls overall signal level for both channels
(see rear panel mode switch description).
Protect
3
This Red LED indicates that the amp channel is in Protect mode.
During Power up, the amp briefly goes into protect mode in order
to prevent any loud spikes from being fed to the speakers. After a
few seconds the amp comes out of protect mode and is ready for
normal operation. If the amp stays in Protect mode, this indicates
that there may be a problem internal to the amp. If the amp goes
into Protect mode during operation this indicates that either a
problem has developed internal to the amplifier or the amplifier is
being over-stressed due to an over-current (short circuit or a load
impedance below the operating range), or thermal condition. In this
event, the amplifier should be switched OFF, and the load connections
checked for shorts and proper load impedance. If overheating is
suspected, allow the amplifier to cool and check that the airflow is
not impeded.
ACL / IGM
4
5
This Red LED illuminates when either the ACL or IGM protection
circuitry is engaged. See Section 6,Tourclass Protection for more
information on these Crest-exclusive features.
-24, -18, -6, 0dB
The first three LEDs (-24, -18, -6,) are Green and the last led, 0dB is
yellow. These LEDs respond to the incoming program material as peak
meters. Under normal operating conditions the Green LEDs illuminate
with the dynamics of the program material and theYellow LED flashes
during the loudest peaks.
Signal
6
7
Green LED varies in intensity in response to signals below -24 dB.
Active
Green LED illuminates when the amp is on to show that the channel
is active.
Fan Outlet Grill
8
CD Series amplifiers are cooled by a single rear-mounted fan.
Cool air flows over the heat sink and exhausts through the front grill.
Make sure this outlet remains clear to allow unrestricted airflow.
The power only breaks
one side of the AC
mains. Hazardous energy
may be present in the
enclosure when the
power switch is in the off
position.
a
9 Power switch
This switch turns the amp on and off. If the amp doesn’t turn on when
the switch is in the ON position, check the circuit breaker on the rear
panel.
p. 11
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features overview
CD owner’s manual
3
2
3
4
1
7
6
2
1
3
2
1
3
5
8
rear panel legend
rear panel
input connection
IEC power connector
1
XLR connector polarity
TRS connector polarity
Accepts a standard IEC terminated power cable
Breaker
2
bridged mono mode
parallel mode
Resettable circuit breaker - no fuses are used. Breaker can trip due to
a power surge or over-voltage condition. If it trips once, reset it. If it
continues to trip, the amplifier may need servicing.
stereo mode
Fan
3
chassis ground lifted-position
The fan operates continuously while the amp is on. An internal
temperature sensor increases the speed of the fan during high
temperature conditions. Air enters through the rear of the
amp and exits through the front grill. Be sure to allow adequate air
flow from the rear of the rack the amp is mounted in.
chassis ground grounded-position
output connection
speakon output
channel A stereo/parallel
channel B stereo/parallel
bridged mono
five-way binding post
channel A stereo/parallel
bridged mono
channel B stereo/parallel
p. 12
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features overview
3
Never connect a speaker of LESS
than 2Ω minimum impedance to an
individual channels’ output connections
when operating in STEREO or PARAL-
LEL mode.
a
rear panel
Output connections
4
Speakers can be connected via the high current binding posts and
the industry-standard Speakon (NL-4) connectors.
Never connect a speaker of LESS
than 4Ω minimum impedance to
Channel A and B “+” output connec-
tions when operating in BRIDGE
mode. In BRIDGE mode operation, the
amplifier can produce output voltages
exceeding 120VRMS. Use extreme cau-
tion.
Binding posts: One pair (Red- hot, Black- ground) per channel.
Speakons - One connector for each channel.The Speakon
connector for Channel A also contains contacts for Channel B out
put as well (see Operation Modes).
Ground lift switch
5
Never connect a hot
a
(red) output to ground
The recessed two-position ground lift switch is used to isolate the
amp’s signal ground from the chassis/AC ground.The factory default
setting is to the right, Grounded.To lift, or disconnect the signal
ground from the chassis/AC ground, slide the switch to the left.
Never lift the ground prong on the AC connector.
or to another hot (red)
output!
In situations where an UNBAL-
ANCED signal is fed to the amp, it’s
important to ground the unused
input. If the inverting (-) input of an
amp channel is left floating, the chan-
nels gain will drop by 6 dB. In effect,
the amp will not be as loud. For more
information about this, ask your dealer
or contact Crest Audio Technical
Support directly.
a
Input connections
6
7
8
Input signals can be connected to the amp via the Combi connec-
tors, the 1/4”TRS connectors, and the Female XLR (pin 2 hot) con-
nectors. See Connections
Mode selector switch
Do not adjust the mode
a
selection switch while
This recessed, three position switch configures the amplifier for
Stereo, Parallel or Bridged Mono operation. The default factory
setting is Stereo. See - operation modes.
the amplifier is turned-on.
Input sensitivity switch
This three position switch allows the user to select the input
sensitivity to .775v (0 dBu), X20, or X40 for full rated output
power.The default factory setting is X20.
p. 13
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operation modes
4
/
/
/
choosing the appropriate mode
stereo
switching between operation modes
special considerations when using bridged mode
parallel
bridged
p. 15
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operation modes
CD owner’s manual
4
mode selection
The three-position, recessed Mode Select switch (located on the rear panel)
configures the amplifier for Stereo, Parallel or Bridged mode. Amplifiers are
factory-configured for Stereo mode. Shut the amp off before changing
modes.
stereo
In Stereo mode,both channels operate independently,with their input atten-
uators controlling their respective levels.Signal at ChannelA’s input produces
output at Channel A’s output,while signal at Channel B’s input produces out-
put at Channel B’s output.Recommended minimum nominal load impedance
for stereo operation is 2 Ohms per channel.
parallel
When set to Parallel mode, program material applied to Channel A’s input
will appear at both ChannelA and B outputs.The attenuators for Channel A
and B controls the level for channel A and B outputs independently of each
other.
bridged
Bridged mode straps both amplifier channels together to make a single-
channel monaural amplifier. One channel pushes and the other pulls equally,
increasing the power output over that of either channel alone
(see Specifications). Signal is applied to the Channel A input only. Channel
A’s attenuator is used to control signal level.
Use extreme caution when operating the amplifier in Bridged mode. Never
ground either side of the speaker cable when the amplifier is in Bridged
mode; both sides are “hot.”
If an output patch panel is used, all connections must be isolated from each
other and from the panel.The recommended minimum nominal load imped-
ance in the Bridged mode is 4 ohms, which is the equivalent to driving both
channels separately at 2 ohms.
Connecting amplifier
a
outputs to oscilloscopes
or other test equipment
while the amplifier is
see—connections for examples of mode-specific wirings
in bridged mode may
damage both the amplifier
and test equipment!
p. 16
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connections
5
/
speakon
binding post
proper wiring schemes for connectors:
input
XLR 1/4” TRS
Combi
/
correct signal paths: stereo, parallel and bridged
output
Binding Posts
Speakons
p. 17
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connections
CD owner’s manual
5
inputs
CD amplifiers are configured standard with pin 2 hot on XLR inputs.
female XLR
TRS pinouts
outputs
Speakers are connected using the high-current five-way binding posts,
speakon connectors, or both.
Very high current is
a
available at the outputs.
bridged mono
stereo/parallel
Please connect your
output cable to the + and
- terminals of each sec-
tion precisely as shown.
A Channel ONLY
A and B channel
Speaker + to PIN 1+
Speaker - to PIN 2+
Speaker + to PIN 1+
Speaker - to PIN 1-
A channel also has
B channel + to PIN 2+
B channel - to PIN 2 -
Note: This is useful in
bi-amp monitor situations
see—operation modes
p. 18
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connections
5
stereo mode
five-way binding post connectors
2
1
3
2
1
3
parallel mode
five-way binding post connectors
2
1
3
2
1
3
bridged mono mode
five-way binding post connectors
2
1
3
2
1
3
p. 19
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connections
CD owner’s manual
5
stereo mode
speakon output connectors
A
-
+
2+
1-
2
1
2-
3
1+
2
1
Speaker + to PIN 1 +
Speaker - to PIN 1 -
3
The Channel A Speakon
has the signal from
channel B present on PIN
2- and Pin 2 +.
+
-
a
B
This is handy in situations
where the output is dri-
ving bi-amped monitors.
parallel mode
speakon output connectors
A
-
+
2+
1-
2
1
2-
3
1+
2
1
Speaker + to PIN 1 +
Speaker - to PIN 1 -
3
+
-
B
bridged mono mode
speakon output connectors
-
+
2+
1-
2-
2
1
3
1+
Speaker + to PIN 1 +
2
1
3
Speaker
-
to PIN 2 +
p. 20
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safety
6
/
/
/
the owner’s role in amplifier safety
protecting your speakers
user
responsibility
description of TourClass protection features
speaker
protection
TourClass
p. 21
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safety
user responsibility
CD owner’s manual
6
Your CD Series amplifier is very powerful and can be potentially dangerous to loud-
speakers and operators alike. It is your responsibility to read important pre cautions
(see the inside-front cover) and make sure that the amplifier is installed, wired, and
operated properly as instructed in this manual.
Many loudspeakers can be easily damaged or destroyed by overpowering, especially
with the high power available from a bridged amplifier. Always be aware of the speak-
er’s continuous and peak power capabilities. Crest Audio is not responsible for damage
to loudspeakers for any reason.
see—speaker protection
speaker protection
All loudspeakers have electrical, thermal and physical limits which must be observed to pre-
vent damage or failure.Cone or compression drivers can be damaged (sometimes to the point
of failure) from excessive power, low frequencies applied to high frequency drivers, severely
clipped wave forms, and DC voltage. All CD Series amplifiers automatically protect speakers
from DC voltages and subsonic signals.
see—TourClass protection
Mid- and high-frequency transducers—compression drivers in particular—are highly suscep-
tible to damage from overpowering,clipped wave forms,or frequencies below their rated pass
band.When using an electronic crossover, make absolutely certain that the low and mid bands
are connected to the correct amplifiers and drivers—and not accidentally connected to those
for a higher or lower frequency band.
The amplifier’s clipping point is its maximum peak output power. At maximum peak output
power, Crest Audio CD Series amplifiers will deliver more power than many speakers can
safely handle. Be sure the peak power capability of the amplifier is not excessive for your
speaker system.To ensure that the speakers never receive excessive power, and to prevent
amplifier clipping,use a properly adjusted external limiter (or a compressor with a ratio of 10:1
or higher) to control power output. Use one compressor/limiter for each frequency band in
systems with active electronic crossovers.
The ACL clip limiting circuit will automatically limit the duration of squared-off, continuous
wave forms applied to the speakers.The amplifier will,however,allow normal musical transient
bursts to pass. Of course, when the amplifier does clip, it is operating at its maximum output
power.Note that some speaker systems are packaged with proprietary“processors” that have
power limiting circuits and therefore should not require additional limiting. Do not drive any
low-frequency speaker enclosure with frequencies lower than its own tuned frequency; the
reduced acoustical damping could cause a ported speaker to bottom out even at moderate
power.Consult the speaker system specifications to determine its frequency limits,and employ
a roll-off filter if necessary.
recommended speaker cabling
The wire gauge charts will assist you in determining the optimum copper wire gauge for your
speaker cables.Remember that the speaker cable resistance robs amplifier power in two ways:
2
through power lost directly to resistance (often referred to as I R loss),and through increased
total load resistance, which decreases the amount of power available from the amplifier.
Appendix C gives cable length figures in feet/AWG wire gauges and in metric values.
see—wire gauge
p. 22
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safety
6
®
TourClass protection
Just like Crest Audio’s highly acclaimed Pro series amps, CD series amps incorporate
TourClass protection features. Derived from Crest Audio’s extensive experience with the
world’s largest sound rental companies, the TourClass group of circuits sets the industry
standard for assured protection of internal amplifier circuits and all connected loads.
ACL ACTIVE CLIP LIMITING
At the amplifier’s full power limit, or clipping point, ACL will be activated.This is indicated
by illumination of the ACL / IGM LED.The channel gain is automatically reduced, protecting
the loudspeakers from potential damage from the high power,continuous square waves that
would otherwise be produced. ACL may be activated by uncontrolled feedback, oscillations,
improper equipment gain settings, or an equipment malfunction upstream from the amplifi-
er. Only steady or excessive clipping (not normal program transients) will trigger ACL. The
circuit is virtually transparent in operation and full signal bandwidth is maintained.
IGM INSTANTANEOUS GAIN MODULATION
IGM is an innovative circuit that allows the amplifier to operate safely into loads as low as 4
ohms.When the amplifier sees a load that overstresses the output stage,the IGM circuit adjusts
the channel gain to a safe level. This gain control circuit is inaudible in normal use. In addition,
if extreme and sustained low impedance is encountered, the amplifier’s output relay will open.
AutoRamp
Auto Ramp operates every time the amplifier is turned on or is reactivated after a protect
condition is corrected.This exclusive Crest Audio feature gradually increases gain to the atten-
uator setting avoiding unnecessary stress on the loudspeakers.
Thermal Protect
Abnormally high heat sink temperatures will engage the Protect circuit and disconnects the
output relays. During this time the Prot LEDs will light red.The cooling fan will continue run-
ning at high speed. Normal operation resumes once the amplifier cools to a safe level.
Short Circuit
If an output is shorted (i.e. defective speakers or crossed speaker wires) the output relays will
open and the channel will shutdown.After approximately 2 seconds the channel will attempt
an AutoRamp re-start. If the short is still present the cycle will repeat. If the short is removed
the channel will complete a re-start and operate correctly.
DC Voltage
If an amplifier channel detects DC voltage at its output terminals, the output relay will immediately
open to prevent loudspeaker damage. The protect LEDs illuminate.
Subsonic Frequencies
Built-in high pass filtering provides subsonic frequency protection for each channel.In addition,
at the output.
a relay will open if excessive subsonic energy appears
p. 23
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service and support
7
/
/
when to get support
support
ways to contact Crest Audio
contact us
p. 25
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service and support
CD owner’s manual
7
support
In the unlikely event that your amplifier develops a problem, it must be
returned to an authorized distributor, service center, or shipped directly to
our factory.
To obtain service, contact your nearest Crest Audio Service Center,
Distributor, Dealer, or any of the worldwide Crest Audio offices. For those
with Internet access, please visit the Crest Audio web site.
contact us
customer service
phone 201.909.8700 USA
fax
201.909.8744 USA
email customerserve@crestaudio.com
technical support
phone 201.909.8700 USA
fax
201.587.0550 USA
email techserve@crestaudio.com
web site
For replacement
+
mail
Crest Audio Inc.
packaging, call Crest
Audio’s Customer Service
16-00 Pollitt Drive
Fair Lawn, NJ 07410 USA
p. 26
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specifications
a
CD Series
1000
1500
2000
3000
1kHZ, 0.2%THD+N
Stereo power 8Ω 280W
4Ω 500W
400W
560W
800W
750W
1000W
1000W
2000W
2000W
72 Vrms
1500W
1500W
3000W
3000W
85 Vrms
2Ω1 500W
750W
Bridged mono power 8Ω 1000W
4Ω1 1000W
1500W
1500W
64 Vrms
Maximum output voltage rms each channel 53 Vrms
1
1kHZ, 0.4%THD+N
Frequency response 1W @ 8Ω 20Hz–20kHz, +1/-1dB
Power bandwidth @ rated power 20Hz–20kHz, +1/-1dB
Damping Factor 400:1 @ 8Ω
20Hz–20kHz, +1/-1dB
20Hz–20kHz, +1/-1dB
400:1 @ 8Ω,
20Hz–20kHz, +1/-1dB
20Hz–20kHz, +1/-1dB
400:1 @ 8Ω,
20Hz–20kHz, +1/-1dB
20Hz–20kHz, +1/-1dB
400:1 @ 8Ω,
Input cmrr 60dB @ 1 kHz
Input sensitivity for full rated output power 0.775V / X20 / X40
Input impedance 20K balanced /
60dB @ 1 kHz
60dB @ 1 kHz
60dB @ 1 kHz
0.775V / X20 / X40
20K balanced /
10K unbalanced
>-100dB
0.775V / X20 / X40
20K balanced /
10K unbalanced
>-100dB
0.775V / X20 / X40
20K balanced /
10K unbalanced
>-100dB
10K unbalanced
Hum and noise (A-weighted below rated power) >-100dB
Crosstalk >-60dB @ 1kHz below rated power >-60dB @ 1kHz below rated power >-60dB @ 1kHz below rated power
Class
D
D
D
D
Circuit breaker rating 120Vac 10A
Circuit breaker rating 230Vac 6A
12A
8A
15A
20A
10A
12A
Current draw 1/8 power, 4Ω 120Vac 2.6A
Current draw 1/3 power, 4Ω 120Vac 5.3A
3.6A
7.5A
1.1A
614
4.5A
9.6A
1.25A
781
7.0A
14.0A
1.5A
1024
1.0A
484
Current draw idle 120Vac
Thermal emissions 1/3 Power, 4Ω, BTU/HR
Cooling Back to front via variable speed fan (all models)
Input connectors, per channel Female XLR pin 2+, 1/4” TRS Combo connectors (all models)
Output connectors Speakon connectors and 5 way binding post (all models)
Controls Front panel: two attenuators, power switch. Rear panel: signal ground-lift, mode select, circuit breaker (all models)
LED indicators ACL, IGM, protection, 5 segment bargraph VU meter, Active (all models)
TourClass protection ACL, IGM, AUTORAMP. short circuit, DC Voltage Turn ON/OFF transient,
current in-rush, sub/ultrasonic input (all models)
Construction 16 guage steel chassis
Dimensions Inches: 3.5 height x 19 width x 15.3 depth / MM: 89 height x 483 width x 389 depth (all models)
Weight net 30 lbs / 13.6 kG
35 Lbs / 15.9 kG
38 Lbs / 17.2 kG
41.4 Lbs / 18.8 kG
p. 27
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block diagram
CD owner’s manual
b
Channel A
Inputs
Channel A
Outputs
OUTPUT STAGE
5-Way
Neutrik
Speakon
A
ACL, IGM,
DC PROTECT,
AUTORAMP
Binding Posts
ATTENUATOR
1/4”
TRS
THERMAL
1
3
Female
3-Pin XLR
2
OUTPUT
RELAY
0.775V
X20
A
B
VU METER
X40
GAIN
SWITCH
-
0.775V
X20
Channel B
Inputs
Channel B
Outputs
X40
OUTPUT STAGE
MODE
SWITCH
5-Way
Binding Posts
Neutrik
Speakon
ACL, IGM,
DC PROTECT,
AUTORAMP
C
B
1/4”
TRS
A
A: PARALLEL
B: STEREO
C: BRIDGED
THERMAL
1
3
Female
3-Pin XLR
2
OUTPUT
RELAY
B
ATTENUATOR
VU METER
SEE SECTION 5 FOR
OUTPUT CONNECTION DETAILS
p. 28
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optional handle installation
c
The CD amplifiers can be outfitted with optional handles.This option requires (2) CD series handles
(P/N C32000010) and (4) #8-32 1/2” undercut flat head screws (P/N C38000008).You may order
these from your dealer or directly from Crest Audio.
p. 29
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d
wire gauge
CD owner’s manual
stranded cable length
wire gauge
0.3mm2
power loss
8 Ω load
4 Ω load
2 Ω load
2 meters
2.9%
5.6%
10.8%
0.5
0.75
1.5
2.5
4.0
1.74
1.16
0.58
0.35
0.22
3.4
6.7
2.3
4.5
1.16
0.70
0.44
2.3
1.39
0.87
5 meters
0.5mm2
0.75
1.5
2.5
4
4.3%
2.9
8.2%
5.6
15.5%
10.8
5.6
1.45
0.87
0.55
0.37
2.9
1.74
1.09
0.73
3.4
2.2
6
1.45
0.5mm2
0.75
1.5
2.5
4
8.24%
5.6
5.5%
10.8
5.6
28%
19.9
10.8
6.7
meters
10
2.9
1.74
1.09
0.73
2.9
1.74
1.09
4.3
6
2.9
0.75mm2
15.5%
8.2
0.73%
15.5
9.8
45%
28
meters
30
1.5
2.5
4
5.1
18.2
12.0
8.2
3.2
6.3
6
2.2
4.3
10
1.31
2.6
5.1
p. 30
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wire gauge
d
stranded cable length
wire gauge
power loss
8Ω load
4Ω load
2Ω load
18AWG
0.81%
1.61%
3.2%
feet
5
16
14
12
10
0.51
0.32
0.20
0.128
1.02
0.64
0.40
0.25
2.0
1.28
0.80
0.51
18AWG
16
1.61%
1.02
0.64
0.40
0.25
3.2%
2.0
6.2%
4.0
feet
10
40
80
14
1.28
0.80
0.51
2.5
12
1.60
1.01
10
18AWG
6.2%
4.0
11.9%
7.7
22%
14.6
9.6
feet
16
14
12
10
8
2.5
5.0
1.60
1.01
0.60
3.2
6.2
2.0
4.0
1.20
2.4
18AWG
11.9%
7.7
22%
14.6
9.6
37%
26
feet
16
14
12
10
8
5.0
17.8
11.8
7.7
3.2
6.2
2.0
4.0
1.20
2.4
4.7
p. 31
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P/N 80305114
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