Crest Audio CA4 User manual

Product Description
The Crest Audio CA4 professional power amplifier is designed
to achieve unsurpassed sonic performance and long-term reliabil-
ity—even when operating under extreme stress—in touring or
fixed installation applications.
Absolute sonic accuracy is the hallmark of every Crest amplifier.
Bass is solid and defined to the limits of audibility, with ample
current reserves delivered by an “over-engineered” power supply
and advanced Class AB output circuit design. Wide-bandwidth
output devices assure detailed, transparent high frequency
response. And, thanks to Crest’s exclusive IGM circuit, the CA4
will drive 2Ωloads safely without compromise in performance.
Construction and Quality Control
The CA4 is built exclusively in Crest’s own USA manufacturing
facility, with internal components selected for premium quality
and proven durability. Each modular subassembly is pre-tested,
and the assembled CA4 receives a rigorous “hot room” burn-in
before thorough final checkout on precision test equipment.
CA4 Features
• Crest’s legendary “overbuilt” power supply
• Toroidal power transformer
• Latest generation of high-speed, wide-bandwidth output
devices
• Twin tunnel cooling with back-to-front air flow
• Dual, variable speed DC fans
• Massive, extruded aluminum heat sinks
• Balanced XLR and 1/4-inch (TRS) inputs
• 5-Way binding post outputs or Speakon™ connectors
(market dependent)
• Stereo/parallel/bridged mono mode selector switch
• Ground lift switch
• TourClass® protection circuits:
- ACL (Active Clip Limiting) prevents speaker damage with
gentle gain reduction at clip threshold.
- IGM (Instantaneous Gain Modulation) monitors speaker
loads to detect conditions that may overstress output
devices, allowing safe operation into nominal 2Ωimped-
ances.
- AutoRamp gradually increases gain to attenuator setting
level when amplifier is turned on.
- TourClass also includes comprehensive thermal manage-
ment, and short circuit, DC voltage, turn-on/off transient,
current inrush and sub/ultrasonic input protection.
• Input sensitivity selection
• Recessed, stepped attenuators
• Front panel circuit breaker switch
• Modular construction
• Five-year warranty*
Power Specifications 8ΩStereo 4ΩStereo 2ΩStereo 8ΩBridged 4ΩBridged
1kHz, 0.01% THD+N 250W 435W 500W 830W 1100W
20Hz-20kHz, 0.1% THD+N 245W 400W 450W 800W 900W
Figures are watts per channel, both channels driven.
4ΩStereo CA2 CA6 CA9 CA12 CA18
1kHz, .01% THD+N 250W 600W 900W 1200W 1800W
20Hz-20kHz, 0.1% THD+N 200W 500W 800W 1100W 1700W
Power Specifications:
Other CA Series Power Amplifiers
CA4 POWER AMPLIFIER

v. 2.6 11/25/97 B5000016
Crest Audio Inc.
100 Eisenhower Dr., Paramus NJ 07652 USA
TEL: [phone] FAX: [phone]
http://www.crestaudio.com
CA4 POWER AMPLIFIER
SPECIFICATIONS
RISK OF ELECTRIC SHOCK
DO NOT OPEN
AVIS: RISQUE DE CHOC ÉLECTRIQUE—NE PAS OUVRIR
WARNINGTO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT
EXPOSETHIS EQUIPMENT TO RAIN OR MOISTURE.
ATTENTION! POUR ÉVITER LE RISQUE D'INCENDIE OU DE CHOC
ÉLECTRIQUE,NE PLACEZ PAS CET APPAREIL SOUS LAPLUIE OU Á
L'HUMIDITÉ
CAUTION
A
AB
AB
ADesigned & manufactured in the USA by:
Crest Audio Inc.
100 Eisenhower Dr.
Paramus, New Jersey 07652 USA
1 3- 2+
+
A
A
B
B
••
••
+
+
+
A
B
B
A
A
B
Designed & manufactured in the USA by:
Crest Audio Inc.
100 Eisenhower Dr.
Paramus, New Jersey 07652 USA
A
AB
AB
A
1 3- 2+
+
••
••
B
A
NL4FC
B
A
A
B
643-105
A
A
B
B
Power figures are watts per chan-
nel, both channels driven.
* 3-Year Warranty with 2 addi-
tional years if Registration Card
is sent to Crest Audio. (USA,
Canada, United Kingdom, and
many other countries).
Crest Audio reserves the right to
make improvements in manufac-
turing or design which may affect
specification.
Crest Audio specification litera-
ture is available in downloadable
PDF format; visit our website at:
http://www.crestaudio.com.
©1997 Crest Audio Inc.
Rear View,
Binding Post
Version
Rear View,
Speakon
Version
(not available in
North America)
1kHz, 0.01% THD+N 20Hz-20kHz, 0.1% THD+N
250W 245W
435W 400W
500W 450W
830W 800W
1000W 900W
58V
82V
20Hz-20kHz, -3dB@135kHz
20Hz-20kHz, -.9dB/+.5dB
ACL, IGM, AutoRamp, short circuit, DC voltage,
turn-on/off transient, current inrush, sub/ultrasonic input.
<0.01%
<0.01%
550:1
> - 60dB
0.775V standard (see table below)
X61 standard (see table below)
>20kΩ/>10kΩ
-105dB
> - 60 dB
AB
Female XLR (pin 2+, dealer configurable for pin 3+), TRS (tip+)
5-way output binding posts or Speakon connectors (market dependent)
27,200 µF
100V-240V, 50-60Hz
1.4A
6.8A
10.0A
15A
2030 BTU/hr
2726 BTU/hr
Back-to-front via 2 rear panel mounted variable-speed DC fans
(filters removable without tools)
Front Panel: 2 attenuators
Rear Panel: signal ground lift switch, mode select switch
Clip/Limit, Signal, Temp/DC, Active
Steel chassis, 16 gauge. Double thickness in rack ear areas.
3.5" x 19" x 18" / 89 x 483 x 457mm
46 lbs. / 20.88 kg., 41 lbs. / 18.61 kg.
5 years*
8ΩStereo Power
4ΩStereo Power
2ΩStereo Power
8ΩBridged Mono Power
4ΩBridged Mono Power
Max RMS Output Voltage (each channel)
Peak Output Voltage (each channel)
Frequency Response (+0 / -0.3dB, 1W/8Ω)
Power Bandwidth (rated power at 4Ω, 1% THD+N)
TourClass®Protection
THD+N (rated power at 4Ω, 1kHz)
SMPTE IMD (rated power at 8Ω, 60Hz & 7kHz)
Damping Factor (10-400Hz at 8Ω)
Input CMRR (1kHz)
Input Sensitivity (rated power at 8Ω)
Voltage Gain
Input Impedance (balanced/unbalanced)
Hum and Noise (“A” weighted, full power, 4Ω)
Crosstalk (“A” weighted, full power, 4Ω)
Class
Input Connectors (per channel)
Output Connectors (per channel)
Filter Storage
Power Supply (factory configured)
Idle Current Draw 120V
1/8 Power Curr. Draw (typical music, 120V/4Ω)
1/3 Power Curr. Draw (continuous music, 120V/4Ω)
Max Curr. Draw (circuit breaker rating, 120V/4Ω)
Thermal Emissions (1/8 Power, 4Ω)
Thermal Emissions (1/3 Power, 4Ω)
Cooling
Controls
LED Indicators (per channel)
Construction
Dimensions (Height x Width x Depth)
Gross Weight, Net Weight
Warranty
Gain Sens
Dealer-Configurable Gain/Sensitivity Options Factory Standard X61 .775V
Option 1 X40 1.12V
Option 2 X20 2.24V
*B5000016*
Architect’s & Engineer’s Specifications
The power amplifier shall have two channels. At 8 ohms, 20Hz
- 20kHz, 0.1% THD+N, it shall deliver a minimum of 245 watts
per channel. At 4 ohms, 20Hz - 20kHz, 0.1% THD+N, it shall
deliver a minimum of 400 watts per channel. In bridged mono
mode with an 8 ohm load, 20Hz - 20kHz, 0.1% THD+N, it
shall deliver a minimum of 800 watts.
Two rear panel mounted variable speed DC fans (filters
detachable without tools) shall provide back to front air flow
through the chassis.
The amplifier shall have circuitry to protect itself from output
short circuits, thermal overload or other adverse load condi-
tions. The amplifier shall protect speaker loads from DC volt-
age on outputs. The amplifier shall have active clip limiting
and impedance sensing circuitry. Output relays shall protect
the speakers from amplifier failure.
Each channel shall have a standard (factory-set) input sensitiv-
ity of 0.775 Volts, and shall be fitted with an internal jumper
which allows the gain to be altered to X20 or X40. The hum
and noise level shall be 105 dB below rated output, “A”
weighted. SMPTE IMD shall be less than 0.01% at rated
power, 60Hz and 7kHz. The amplifier shall have a class AB
output stage. The frequency response shall be 20Hz-20kHz,
+0, -0.3dB (1W/8Ω).
The amplifier will operate at 100V-240V, 50-60 Hz AC (config-
ured at factory). Maximum current draw shall not exceed 15
amperes at 120VAC (limited by front panel breaker for bench
tests).
Front panel indicators shall include Active, Protect, Signal,
and Clip LED’s for each channel. Front panel attenuators
shall be recessed and detented.
Rear panel input connectors shall be female TRS and XLR
type, internally dealer-configurable for pin 2 (factory setting)
or pin 3 positive. Output terminations shall be 5-way output
binding posts or Speakon output connectors (market depen-
dent). A ground lift switch and a Stereo/Parallel/Bridged Mono
mode operation switch shall be provided.
A rear-panel IEC AC mains socket (with power cord) or single
AC mains cord having an appropriate AC plug for the intended
operating voltage shall be provided (market dependent).
The packaging of the amplifier shall allow for standard rack
mounting without requiring space between similar units.
Optional rack mount handles will be available. Dimensions
shall be 19" (483mm) wide, 3.5" (89mm) high and 18"
(457mm) deep. The amplifier shall weigh 41 lbs. (18.61 kg.)
net, and shall be designated the Crest Audio model CA4.