PROFESSIONAL POWER AMPLIFIERS Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier OWNER’ S MANUAL
Important Precautions This symbol is used to alert the operator to follow important operating procedures and precautions detailed in documentation. This symbol is used to warn operators that uninsulated “dangerous voltages” are present within the equipment enclosure that may pose a risk of electric shock. 1. Save the carton and packing material even if the equipment has arrived in good condition. Should you ever need to ship the unit, use only the original factory packing. 2.
Power Amplifier Owner’s Manual Table of Contents Introduction Unpacking Installation and Mounting Front Panel Rear Panel Internal Configuration and Control Operation Connecting Power / Circuit Size Requirements Cooling Requirements Connecting Inputs Connecting Outputs Mode Selection Stereo /Parallel/Bridged Mono Connections TourClass® Protection Features User Precautions Speaker Protection Recommended Speaker Cabling Maintenance User Responsibility Service and Repair Appendix A Appendix B Appendix C Append
CA12, CA18 Front View Front height 5.25" 133mm Professional Power Amplifier Front width 19" / 483mm CA2-9 Front View Front height 3.5" 89mm Professional Power Amplifier Front width 19" / 483mm Rear & Side Views A A A + + AB • • 3.5" 89mm A A + B A B + A B •• B A B B 2+ 1 3- 5-way binding post version shown. 17.9"/437mm (19"/483mm to rack ears) 2+ 1 3- A A A 5.25" 133mm • • A AB A + B A B A B B A B •• B CA2 CA4 CA2-9 CA6 CA9 1.
Introduction Congratulations on your purchase of a new CA Series professional power amplifier, and thank you for your confidence 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.
Front Panel 1 2 3 4 5 6 7 8 9 Professional Power Amplifier 1. Rack Mounting Ears. Two front panel mounting holes are provided on each mounting ear. 2. Optional Rack Handles. Available from your authorized Crest Audio supplier. Never try to hold the circuit breaker/power switch in the “ON” position if it won’t stay there itself! 3. Fan Outlet Grills. CA Series amplifiers are cooled by two, rear-mounted fans. Cool air flows over the heat sinks and exhausts through the front grills.
Rear Panel See Appendix E for information specific to model CA18. A A CAUTION + + ATTENTION! POUR ÉVITER LE RISQUE D'INCENDIE OU DE CHOC ÉLECTRIQUE, NE PLACEZ PAS CET APPAREIL SOUS LA PLUIE OU Á L'HUMIDITÉ Designed & manufactured in the USA by: A AB • • Crest Audio Inc. 100 Eisenhower Dr.
13-14. Balanced 1/4" (TRS) & XLR Input Connectors. Tip - Positive (+) NOTE: Unbalanced “Tip/Sleeve” plugs may be used with the balanced TRS “Tip/Ring/Sleeve” connectors. The “ring” terminal or negative input will be connected to ground internally. When using three-pole (‘stereo’) TRS connectors, make sure that the ring connection is made either to the cold (–) output of the source equipment, or to ground. Incorrect connections may cause a 6dB loss in level.
Operation Connecting Power / Circuit Size Requirements. CA Series amplifier power requirements are rated at: a) “idle” b) 1/8th power (“typical” music conditions) c) 1/3rd power (“continuous” music conditions) d.) maximum rated power (circuit breaker limited). The maximum power current draw rating is limited only by the front panel circuit breaker. Consult the specifications in the Appendices section for figures on the current that each amplifier will demand.
Connecting Inputs. Use either the XLR or 1/4-inch input connectors on the rear to supply audio signals to your Crest Audio CA Series amplifier. Both connectors accept balanced and unbalanced audio connections. (The CA Series amplifiers are configured standard with “Pin 2 hot” on XLR inputs. Please note that some other Crest Audio amplifiers are configured with “Pin 3 hot”). The unused connector can be used to jumper the audio input to another amplifier input.
Mode Selection. The three-position, recessed Mode Select switch (located on the rear panel) configures the amplifier for either Stereo, Parallel or Bridged Mono Mode. Amplifiers are factory-configured for Stereo Mode. Stereo Mode. In Stereo Mode, both channels operate independently, with their input attenuators controlling their respective levels. Signal at Channel A’s input produces output at Channel A’s output, while signal at Channel B’s input produces output at Channel B’s output.
Stereo Mode Connections (5-Way Output Binding Posts) A or A A A A + + A • • AB A A + NOTE: the Binding Post version of the CA18 features two pair of 5-Way Output Binding Posts.
A Stereo Mode Connections (Speakon Output Connectors) or - + A A 2+ NL4FC 1- A A A 2- • • A AB A + 1+ B A B Speaker + to PIN 1 + Speaker - to PIN 1 - B • • A B A B B 2+ 1 3- - B + B or B A Parallel Mode Connections (Speakon Output Connectors) or - + A 2+ A NL4FC 1- A A A 2- • • A AB A + 1+ B A B Speaker + to PIN 1 + Speaker - to PIN 1 - B A B • • A B B 2+ 1 3- - + A Bridged Mono Mode Connections (Speakon Output Connectors) Bridged/Mono - or A A
TourClass® Protection Every model in the CA Series incorporates 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 Clip LED.
User Precautions Speaker Protection All loudspeakers have electrical, thermal, and physical limits which must be observed to prevent 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 waveforms, and DC voltage. All CA Series amplifiers automatically protect speakers from DC voltages and subsonic signals. For more information, see the TourClass Protection section.
Maintenance A CA Series amplifier requires no routine maintenance other than occasional cleaning or replacement of the fan intake filters on the rear of the amplifier. (This operation does not require any tools). Filters must be kept clear and clean to ensure proper ventilation through the unit.
Appendices
Appendix A - Amplifier Specifications 1kHz, 0.01% THD+N 8Ω Stereo Power 160W 250W 400W 600W 700W 1000W (.03% THD+N) 4Ω Stereo Power 250W 435W 600W 900W 1200W 1800W (.03% THD+N) 2Ω Stereo Power N/A 500W 750W 1000W 1400W 2500W (.03% THD+N) 8Ω Bridged Mono Power 500W 830W 1200W 1800W 2400W 3600W (.03% THD+N) 4Ω Bridged Mono Power N/A 1000W 1500W 2000W 2800W 5000W (.
Appendix B - CA Block Diagram R T CHANNEL A PREAMP + NON-INVERTED 2 † 2/3 3 - 1 OUTPUT STAGE INVERTED PIN 2 / 3 + JUMPER (REAR PANEL SWITCH ON CA18) A + A - AMP FRONT END BRIDGED PARALLEL STEREO R SWITCH OUTPUT RELAY † PREAMP INCORPORATES INPUT SENSITIVITY/VOLTAGE GAIN JUMPER (REAR PANEL SWITCH ON CA18) + - † ATTENUATOR OUTPUT STAGE PREAMP T CHANNEL B B NON-INVERTED + 2 3 ATTENUATOR AMP FRONT END OUTPUT RELAY 2/3 B 1 - INVERTED PIN 2 / 3 + JUMPER (REAR PANEL SWITCH ON CA
Appendix C - Wire Gauge Chart (Metric) Stranded Cable Lgth. (m) Wire Gauge (mm2) Power Loss (8 ohm load) Power Loss (4 ohm load) Power Loss (2 ohm load) 2 0.3 2.9% 5.6% 10.8% 0.5 1.74 3.4 6.7 0.75 1.16 2.3 4.5 1.5 0.58 1.16 2.3 2.5 0.35 0.70 1.39 4 0.22 0.44 0.87 0.5 4.3% 8.2% 15.5% 0.75 2.9 5.6 10.8 1.5 1.45 2.9 5.6 2.5 0.87 1.74 3.4 4 0.55 1.09 2.2 6 0.37 0.73 1.45 0.5 8.24% 15.5% 28% 0.75 5.6 10.8 19.9 1.5 2.9 5.6 10.8 2.5 1.74 2.9 6.
Appendix C - Wire Gauge Chart (Imperial) Stranded Cable Lgth. (ft.) Wire Gauge (AWG) Power Loss (8 ohm load) Power Loss (4 ohm load) Power Loss (2 ohm load) 5 18 0.81% 1.61% 3.2% 16 0.51 1.02 2.0 14 0.32 0.64 1.28 12 0.20 0.40 0.80 10 0.128 0.25 0.51 18 1.61% 3.2% 6.2% 16 1.02 2.0 4.0 14 0.64 1.28 2.5 12 0.40 0.80 1.60 10 0.25 0.51 1.01 18 6.2% 11.9% 22% 16 4.0 7.7 14.6 14 2.5 5.0 9.6 12 1.60 3.2 6.2 10 1.01 2.0 4.0 8 0.60 1.20 2.
Appendix D Rear Panel Symbols - Legend Input Connection Section XLR Connector Polarity Indicator 2+ 1 3- + TRS Connector Polarity Indicator A Mode Selection Switch - Bridged Mono Position AB A Mode Selection Switch - Parallel Position A B A B Mode Selection Switch - Stereo Position A B Chassis Ground Lift Switch - Ground Lifted Position Chassis Ground Lift Switch - Grounded Position GAIN Gain Select Switch (CA18) Ø 40x 20x dBu XLR Pin + 2 XLR pin hot (+) select switch (CA18) 3 Output Connect
Appendix E CA18 Power Amplifier - Special Functions The CA18 rear panel features external switches for the following: XLR Pin+ Switch: This switch configures XLR input connection polarity. Either pin 2 or pin 3 may be selected as the “hot” (+) pin. Amplifiers are shipped pin 2 “hot” (+) from the factory. Gain Switch: This switch permits the amplifier to be configured for the standard input sensitivity (.775V for rated power @ 8Ω), or for optional voltage gains of X40 or X20.
Crest Audio Inc. 100 Eisenhower Dr., Paramus NJ 07652 USA TEL: 201.909.8700 FAX: 201.909.8744 http://www.crestaudio.com Printed in USA v. 2.9 11/25/97 © 1997 Crest Audio, Inc. Choice of touring professionals.
