CPA Series Owner`s Manual
Contents
1. 0 1 THD N 400 CPA600 CPA900 CPA1200 CPA1800 8Q Stereo Power 225W 400W 575W 700W 950W 03 THD N 40 Stereo Power 400W 600W 825W 1100W 1700W 03 THD N 80 Bridged Mono Power 800W 1200W 1650W 2200W 3200W 03 THD N 20Hz 20kHz 0 1 THD N 8Q Stereo Power 225W 350W 550W 650W 950W 40 Stereo Power 400W 500W 800W 1100W 1700W 80 Bridged Mono Power 800W 1000W 1600W 2200W 3400W Max RMS Output Voltage each channel 58V 73V 82V 90V 99V Max Peak Output Voltage 82 103V 116V 126V 140V Frequency Response 0 0 3dB 1W 8Q Power Bandwidth rated power at 4Q 1 THD N 20Hz 20kHz 3dB 135KHz 20Hz 20kHz 9dB 5dB 20Hz 20kHz 135kHz 20Hz 20kHz 23dB 85dB 20Hz 20kHz 3dB 135kHz 20Hz 20kHz 1 1dB 0dB 20Hz 20kHz 3dB 135kHz 20Hz 20kHz 84dB 0dB 20Hz 20kHz 3dB e 150kHz 20Hz 20kHz 2dB 2dB TourClass Protection ACL IGM AutoRamp short circuit DC voltage turn on off transient current inrush sub ultrasonic input THD N rated power 4Q 1kHz 0 196 lt 0 1 lt 0 1 lt 0 1 lt 0 1 SMPTE IMD rated power 80 60 Hz amp 7kHz 0 0196 lt 0 01 lt 0 01 lt 0 01 lt 0 01 Damping Factor 10 400Hzat8O 550 1 400 1 700 1 800 1 800 1 Input CMRR 1kHz 60dB gt 60 dB gt 60 dB gt 60 dB gt 70dB Standard Input Sensitivity rated power at 89 1 4V 14 LAV Standard Voltage Ga2. Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO TourClass Protection Every model in the CPA 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 illumina tion of the Clip 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 mal function upstream from the amplifier 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 Impedance Sensing IGM Instantaneous Gain Modulation is an innovative circuit that allows the amplifier to operate safely into difficult loads When the amplifier sees a load that overstresses the output stage the IGM circuit adjusts the channel gain to a safe level Like ACL the IGM circuit is inaudible in normal use In addition if extreme and s
3. v 1 0 8 6 98 1998 Crest Audio Inc Choice of touring professionals jill A450001 0
4. CA18 XLR polarity amp input sens voltage gain switches LED Indicators per channel Clip Limit Signal Temp DC Active Construction Steel chassis 16 gauge Double thickness in rack ear areas Dimensions Height x Width x Depth to rear rack ears 3 5 x 19 x 18 3 5 x 19 x 18 3 5 x 19 x 18 5 25 x 19 x 18 5 25 x 19 x 18 89 x 483 x 457mm 89 x 483 x 457mm 89 x 483 x 457mm 133 x 483 x 457mm 133 x 483 x 457mm Gross Weight 46165 20 88 kg 49 Ibs 22 24 kg 52lbs 23 60 kg 72 Ibs 32 68 kg 82 Ibs 37 23 kg Net Weight 41 Ibs 18 61 kg 44 Ibs 19 97 kg 47 Ibs 21 33 kg 67 lbs 30 42 kg 77 Ibs 34 96 kg Warranty 5 years 5 yea 5 years 5 years 5 years 1 For full power at 4 Ohms 3 Year Warranty with 2 additional years if Registration Card is sent to Crest Audio USA Canada United Kingdom and many other countries Crest Audio reserves the right to make changes or improvements in manufacturing or design which may affect specification 1998 Crest Audio Inc 6 8 98 Appendix A Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO Appendix B CPA Block Diagram R T CHANNEL A PREAMP NON INVERTED 2 ATTENUATOR 3 2 3 OUTPUT STAGE 1 INVERTED 1 PIN2 3 JUMPER HUM AMP FRONT END OUTPUT RELAY T PREAMP INCORPORATES INPUT BRIDGED SENSITI
5. Protection 15 Recommended Speaker Cabling 15 Maintenance 16 User Responsibility 16 Service and Repair 16 Appendix Specifications Appendix B CPA Block Diagram Appendix C Wire Gauge Charts Appendix D Rear Panel Symbols Legend Appendix E CPA1800 Power Amplifier Special Functions Crest Audio CPA Series Power Amplifiers Page 3 Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO CPA1200 CPA1800 Front View A nS Se C5 E CREST 9 AUDIO gt ED CX F gt DE CX ront rs gt height I e C S25 LEES GL s ww cm 3 3 SS z Signal e MX 133mm O O 51200 DD y s Adve c CAA ChB O 5 X CO Cinema Power Amplifier Y lt lt SS SS Front width 19 483mm gt CPA400 CPA600 CPA900 Front View i C lt __ EEE CREST AUDIO CL CL Front DE DI height I gots AL O aiios DI 3 5 E 7 DD 15 15 89mm Protect a A 90
6. amplifier input For more information see the sections on Balanced 1 4 TRS amp XLR Input Connectors Input XLR Polarity and Input Sensitivity Connecting Outputs Speakers are connected using 5 way Output Binding Posts or Speakon connectors depending on version supplied Please note that on the 5 way Output Binding Post version of the CPA1800 two pairs of 5 way binding posts are provided for each channel so that paralleling of speakers is possible For more information see the Output Connectors and Mode Selection sections Page 10 Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO 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 respec tive 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 Recommended minimum nominal load impedance for stereo operation is 4 ohms per channel Either the 1 4 TRS inputs or the XLR inputs may be used Parallel Mode When set to Parallel Mode a signal applied to Channel A s input will be amplified and appear at outputs for both Channels A amp B Eith
7. state of the art USA manufacturing facility Internal components are the finest available and key sub assemblies are pre tested before final assembly Finally each amplifier is burned in and thoroughly tested using preci sion audio test equipment before shipping In addition all CPA Series amplifiers incorporate Crest s exclu sive 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 guarantee of fail safe reliability You can depend on consistent stable performance even when your CPA Series amplifier is subjected to punishing extremes in the most demanding fixed or mobile sound rein forcement applications Unpacking Please inspect the amplifier carefully immediately after unpacking If you find any damage 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 your packing materials are in good condition please save them If you ever need to ship the unit back to Crest Audio or an authorized service center you should use only the original factory packing Installation and Mounting Three CPA Series amplifiers are 2 rack space units models CPA400 CPA600 and CPA900 Models CPA1200 and CPA1800 are 3 rack spaces
8. 0 DEE SS Cha Cinema Power Ample che 2 C lt Front width 19 483mm Rear amp Side Views Binding Post output model shown J fas o o Ir CPA400 35 CPA600 CPA900 gt eS vai 1 375 I 18 457mm A 35mm 4 133 o o n JI Il CPA1200 2 I 13 CPA1800 Il il il ED EN Speakon output model shown Note see Appendix E for detailed CPA1800 rear panel drawings Page 4 Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO Introduction Congratulations on your purchase of a new CPA 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 The Crest Audio CPA Series is based on the same advanced circuit topologies that have made Crest ampli fiers the choice of touring professionals worldwide CPA Series amplifiers are designed for high operating efficiency and accurate sonic performance across the full audio bandwidth even under stressful conditions In order to maintain strict quality assurance standards all CPA Series amplifiers are built in Crest s
9. 00 CPA1200 CPA1800 CREST Appendix E AUDIO cPA1800 Power Amplifier Special Functions The CPA1800 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 1 4V for rated power 8Q or for optional voltage gains of X40 or X20 Refer to the specifications for input sensitivity values at optional voltage gains of X40 and X20 NOTE on the 5 way Output Binding Post version of the CPA1800 two pairs of 5 way binding posts are provided for each channel so that paralleling of speakers is possible Q ALWAYS power down the amplifier before changing settings with either the XLR Pin switch or the Gain switch CPA1800 Binding Post Version Rear View C C N Crest Audio CPA Series Power Amplifiers Appendix E Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO 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
10. PA1800 Power Loss 8 ohm load 0 81 0 40 6 2 4 0 2 5 1 60 11 9 7 1 5 0 3 2 2 0 1 20 Appendix Wire Gauge Chart Imperial Power Loss 4 ohm load 1 61 1 02 0 64 0 40 0 25 3 2 2 0 1 28 0 51 11 9 77 5 0 3 2 2 0 1 20 229 14 6 9 6 6 2 4 0 2 4 Power Loss 2 ohm load 3 296 2 0 1 28 0 80 0 51 6 296 4 0 2 5 1 60 1 01 22 14 6 9 6 6 2 4 0 24 37 26 Appendix C oes We gt at GAIN 40x 20x dBu XLR Pin 2 3 Appendix D PUT Wife Appendix D CREST Rear Panel Symbols Legend AUDIO Input Connection Section XLR Connector Polarity Indicator TRS Connector Polarity Indicator Mode Selection Switch Bridged Mono Position Mode Selection Switch Parallel Position Mode Selection Switch Stereo Position Chassis Ground Lift Switch Ground Lifted Position Chassis Ground Lift Switch Grounded Position Gain Select Switch CPA1800 XLR pin hot select switch CPA1800 Output Connection Section Speakon Output Connector Channel A Stereo Parallel Speakon Output Connector Channel B Stereo Parallel Speakon Output Connector Bridged Mono 5 Way Binding Post Output Connection Channel A Stereo Parallel 5 Way Binding Post Output Connection Bridged Mono 5 Way Binding Post Output Connection Channel B Stereo Parallel Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA9
11. REST esere SERIES RS MPLIFIE SSIONAL POWER A PROFE BEE CREST 99 AUD SS B SS 555 gt 88 IO SS Sea q e a MAT 4 am 5 J Si y mm 3 E y 5 x SS EE G SSS E A gt EE EEE CREST AUDIO EL EL o F moo vA o o JAN 0 9 AM SSS 5 N p y 5 woe 6 w o SS ChA n SS sche SS I gt 3 ST 99 AUDIO CRE E o T E 1 O Protec TI AM O En Cinema Power Armor SS ov DES AUDIO CREST co o O 5m 3 O ate e o m EM AUDI IO gt SS CREST Cn 5 ma w CRA 1 si 6 ZA SS MAN tos ai AU GKN o meo ee Da DEE nu Cinema Power 5 e iS OWNER S MANUAL Important Precautions This symbol is used to alert the oper ator to follow important operating procedures and precautions detailed in documentation This symbol is used to warn opera tors that uninsulated dangerous v
12. VITY VOLTAGE GAIN JUMPER REAR PANEL SWITCH ON CA18 PARALLEL STEREO ATTENUATOR OUTPUT STAGE SWITCH PREAMP 8 CHANNEL AMP FRONT END OUTPUT RELAY B NON INVERTED INVERTED PIN 2 34 JUMPER REAR PANEL SWITCH ON CA18 Crest Audio CPA Series Power Amplifiers Appendix B Models CPA400 CPA600 CPA900 CPA1200 CPA1800 Stranded Cable Lgth m 2 10 30 Appendix C Appendix C Wire Gauge Chart Metric Wire Gauge mm 0 3 0 5 0 75 1 5 2 5 4 0 5 0 75 1 5 2 5 0 5 0 75 1 5 2 5 0 75 1 5 2 5 10 Power Loss 8 ohm load 2 9 1 74 1 16 0 58 0 35 0 22 4 3 2 9 1 45 0 87 0 55 0 37 8 24 5 6 2 9 1 09 0 73 15 5 8 2 5 1 3 2 2 2 Power Loss 4 ohm load 5 6 3 4 2 3 1 16 0 70 0 44 8 2 5 6 2 9 1 09 0 73 15 5 10 8 5 6 2 9 1 09 0 73 15 5 9 8 6 3 43 2 6 CREST AUDIO Power Loss 2 ohm load 10 8 6 7 4 5 2 3 1 39 0 67 15 5 10 8 5 6 3 4 2 2 1 45 28 19 9 10 8 6 7 4 3 2 9 45 28 12 0 8 2 5 1 Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO Stranded Cable Lgth ft 5 10 40 80 Wire Gauge AWG 18 16 14 12 10 18 16 14 12 10 18 16 14 12 10 8 18 16 14 12 10 Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 C
13. back to the ON position once If it will not stay on the amplifier needs servicing 5 Signal LED Illuminates to indicate that a signal above a minimum threshold is present at the amplifier input and that the signal is being amplified 6 Clip LED Illuminates at the clipping threshold Continuous illumination also indicates that ACL Active Clip Limiting protection circuitry is engaged 7 Active LED Indicates that AC power is connected and the amplifier is turned on 8 Protect LED Indicates that the channel is in Protect mode speakers disconnected by output relay 9 Input Attenuators Attenuators are screwdriver adjustable and allow for precise setting of input gain After adjustment blank ing plugs are supplied to cover the attenuators Page 6 Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO Rear Pa nel See Appendix E for information specific to model CPA1800 10 Output Connectors Two versions market dependent CPA Series amplifiers are supplied with either 5 way Binding Posts or Speakon connectors Connection to the binding posts can be made with bare wire banana plugs or spade lug terminations Make connections to both the Channel A and Channel B terminals for Stereo or Parallel Mode or a single connection across the red terminals only of Channels A and B for Bridged Mono Mode Using Speakon type
14. d the fans will force a very large volume of air through the heat sinks If either heat sink surpasses the maximum allowed temperature the sensing circuit will open the output relay disconnecting the load from that channel If the power trans former overheats another sensing circuit opens both channel output relays until the transformer cools to a safe temperature IMPORTANT To ensure optimum cooling periodically clean the amplifier fan filters removable without tools Also make certain that there is enough space around the front of the amplifier to allow the cooling air to escape If the amplifier is rack mounted do not use doors or covers on the front of the rack the exhaust air must flow out without resistance If the amplifiers are to be housed in racks with closed backs allow at least one 1 standard rack space of opening in the front of the rack for every four amplifiers Crest Audio CPA Series Power Amplifiers Page 9 Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO Connecting Inputs Use either the XLR or 1 4 inch input connectors on the rear to supply audio signals to your Crest Audio CPA Series amplifier Both connectors accept balanced and unbalanced audio connections The CPA 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
15. ed mode may damage both the amplifier and test equipment Crest Audio CPA Series Power Amplifiers Page 11 Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO Stereo Mode Connections 5 Way Output Binding Posts NOTE the Binding Post version of the CPA1800 features two pair of 5 Way Output Binding Posts Parallel Mode Connections 5 Way Output Binding Posts Bridged Mono Mode Connections 5 Way Output Binding Posts Bridged Mono Page 12 Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO Stereo Mode Connections Speakon Output Connectors 2 gt PAG 1 Speaker to PIN 1 Speaker to PIN 1 Parallel Mode Connections Speakon Output Connectors 2 gt gp 2 1 Speaker to PIN 1 Speaker to PIN 1 Bridged Mono Mode Connections Speakon Output Connectors Bridged Mono or A 1 er pa T dif Bie 009 G O Speaker to PIN 1 Speaker to PIN2 Page 13
16. er the 1 4 TRS input or the XLR input on Channel A may be used Bridged Mono Mode Bridged Mono Mode straps both amplifier channels together to make a very powerful single channel monaur al amplifier One channel pushes and the other pulls equally doubling the power over that of either chan nel alone Signal is applied to the Channel A input only Both attenuators are used to control signal level in addition both must be adjusted to the same setting Either the 1 4 TRS or XLR input may be used NOTE The channel B input connectors XLR and or TRS may be used to loop thru the channel A signal when in parallel or bridged mono mode Use extreme caution when operating the amplifier 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 The recommended minimum nominal load impedance in the Bridged Mono Mode is 8 ohms which is the equivalent to driving both channels separately at 4 ohms Driving bridged loads of less than the recommended minimums will activate the IGM circuitry resulting in a loss of power and may also lead to a thermal protect condition See figures on pages 12 amp 13 showing output connection information 4 Connecting amplifier outputs to oscilloscopes or other test equipment while the amplifier is in bridg
17. f there are high signal levels at the inputs 10 11 12 13 14 15 16 17 18 19 Power down and disconnect units from mains voltage before making connections Never hold a power switch in the ON position if it won t stay there itself Do not use the unit near stoves heat registers radiators or other heat producing devices Do not block fan intake or exhaust ports Do not operate equipment on a surface or in an environment which may impede the normal flow of air around the unit such as a bed rug weathersheet carpet or completely enclosed rack If the unit is used in an extremely dusty or smoky environ ment the unit should be periodically blown free of foreign matter Do not remove the cover Removing the cover will expose you to potentially dangerous voltages There are no user serviceable parts inside Connecting amplifier outputs to oscilloscopes or other test equipment while the amplifier is in bridged mode may damage both the amplifier and test equipment Do not drive the inputs with a signal level greater than that required to drive equipment to full output Do not connect the inputs outputs of amplifiers or consoles to any other voltage source such as a battery mains source or power supply regard less of whether the amplifier or console is turned on or off Do not run the output of any amplifi er channel back into another chan nel s input Do not paral
18. high All mount in standard 19 inch racks Four front panel mount ing 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 Optional rack mount handles are available Crest Audio CPA Series Power Amplifiers Page 5 Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST Ao C EQ AUDIO ZZZ DE DD lt ACL MMC gt 5 Signal WV 45 gt E 1 Protect 77 gt A d j DD __ ZSA 80 0dB O Active j Se gt Cinema Power Amplifier 2 CI gt 1 Rack Mounting Ears Never try to hold the Two front panel mounting holes are provided on each mounting ear circuit breaker power 2 Optional Rack Handles switch in the ON position if it won t stay Available from your authorized Crest Audio supplier there itself 3 Fan Outlet Grills CPA Series amplifiers are cooled by two rear mounted fans Cool air flows over the heat sinks and exhausts through the front grills Make sure these outlets remain clear to allow unrestricted air flow 4 AC Power Switch Circuit Breaker CPA Series amplifiers have a front panel combination AC switch and circuit breaker No fuses are used If the switch shuts off during normal use push it
19. in rated power 80 X32 X37 4 X47 4 X53 2 X62 3 Input Impedance balanced unbalanced gt 20kQ gt 10kQ gt 20kQ gt 10kQ gt 20kQ gt 10kQ gt 20kQ gt 10kQ gt 20kQ gt 10kQ Hum and Noise A weighted 80 dBW 105dB 105dB 105dB 105dB 115dB Crosstalk A weighted full power at4Q gt 60dB gt 60dB gt 60dB gt 604 gt 80dB Class H H H Input Connectors per channel Female XLR pin 2 configurable for pin 3 TRS tip Output Connectors per channel 5 way binding posts 2 pair on CA18 or Speakon connectors market dependent Filter Storage 27 200 uF 68 000 pF 80 000 uF 140 000 144 000 uF Power Supply factory configured 100V 240V 50 60Hz 100V 240V 50 60Hz 100V 240V 50 60Hz 100V 240V 50 60Hz 100V 240V 50 60Hz Idle Current Draw 120V 1 4 1 6A 2 0A 2 8A 3 0A 1 8 Power Curr Draw typical music cond 120 40 6 8 6 0A 8 6 10 5 12 0 1 3 Power Curr Draw cont music cond 120V 4Q 10 0 13 0A 16 0A 23 0A 25 0A Max Curr Draw continuous music cond 120V 4Q 15 0A 18 0A 21 0A 30 0A 36 0A Thermal Emissions 1 8 Power 40 2030 BTU hr 2630 BTU hr 3250 BTU hr 4750 BTU hr 7125 BTU hr Thermal Emissions 1 3 Power 40 2726 BTU hr 3713 BTU hr 4341 BTU hr 6300 BTU hr 9450 BTU hr Cooling Two rear panel variable speed DC fans filters detatchable without tools Controls Front panel 2 attenuators magnetic circuit breaker power switch Rear panel signal ground lift amp mode switches
20. irectly to resistance often referred to as PR loss and through increased total load resistance which decreases the amount of power available from the amplifier The charts Appendix C give cable length fig ures in feet AWG wire gauges and in metric values Crest Audio CPA Series Power Amplifiers Page 15 Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO Maintenance A CPA 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 If the amplifier is used in an extremely dusty or smoky environment the filter should be cleaned or changed frequently and the unit should be peri odically blown free using compressed air of any foreign matter that may penetrated through the filter Users will not need to make any internal adjustments to the amplifier during its lifetime There are no user serviceable parts or adjustments that require opening the power amplifier Cover removal exposes the risk of shock so refer all servicing to qualified service technicians authorized by Crest Audio User Responsibility Your CPA Series amplifier is very powerful and can be potentially dangerous to loudspeakers and operators alike It is your responsibility to read the section titled Important Precautions and make s
21. lel or series connect an amplifier output with any other amplifier output Crest Audio is not responsible for dam age to loudspeakers for any reason Do not ground any red hot ter minal Never connect a hot red output to ground or to another hot red output 20 21 22 Non use periods The power cord of equipment should be unplugged from the outlet when left unused for a long period of time Service Information Equipment should be serviced by qualified service personnel when A The power supply cord or the plug has been damaged B Objects have fallen or liquid has been spilled into the equipment C The equipment has been exposed to rain D The equipment does not appear to operate normally or exhibits a marked change in performance E The equipment has been dropped or the enclosure damaged To obtain service contact your nearest Crest Audio Service Center Distributor Dealer or Crest Audio at 201 909 8700 USA CREST Power Amplifier Owner s Manual AUDIO Table of Contents Introduction 5 Unpacking Installation and Mounting Front Panel Rear Panel Internal Configuration and Control Operation Connecting Power Circuit Size Requirements Cooling Requirements 9 Connecting Inputs 10 Connecting Outputs 10 Mode Selection 10 Stereo Parallel Bridged Mono Connections 12 TourClass Protection Features 14 User Precautions 15 Speaker
22. olt ages are present within the equip ment enclosure that may pose a risk of electric shock 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 Read all documentation before oper ating your equipment Retain all doc umentation for future reference Follow all instructions printed on unit chassis for proper operation Do not spill water or other liquids into or on the unit or operate the unit while standing in liquid Make sure power outlets conform to the power requirements listed on the back of the unit 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 paying particular atten tion to cords and plugs convenience receptacles and the point where they exit from the appliance Always operate the unit with the AC ground wire connected to the electri cal system ground Precautions should be taken so that the means of ground ing of a piece of equipment is not defeated Mains voltage must be correct and the same as that printed on the rear of the unit Damage caused by connec tion to improper AC voltage is not cov ered by any warranty Have gain controls on amplifiers turned down during power up to pre vent speaker damage i
23. s located on the rear of the amplifier chassis Be sure not to block these ports when installing the amplifier or other associated equipment Air must flow unim peded through these ports Fan filters removable without tools are provided to minimize entry of dust and dirt Internal Configuration and Control Input XLR Polarity CPA Series amplifiers are supplied standard with the XLR configured as Pin 2 hot On models CPA400 CPA600 CPA900 and CPA 1200 an internal jumper makes it possible to alter the amplifier to Pin hot NOTE This jumper is NOT user configurable Please consult your supplier or local Crest Audio service center if you wish to have the input XLR polarity changed On the CPA1800 an external XLR polarity switch is featured See Appendix E Input Sensitivity The CPA Series amplifiers have a standard input sensitivity of 1 4 Volts for rated power at 8 Ohms Page 8 Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO Operation Connecting Power Circuit Size Requirements CPA 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 spec ifications in the Appendices section for fig
24. s 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 waveforms 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 through power lost d
25. so lated from the chassis AC ground Do not change the switch to the lift position if the amplifier and the signal source equipment are on the same AC ground Should the ground loop problem persist after the ground lift Crest Audio CPA Series Power Amplifiers Page 7 Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO switch has been set to the lift position then the shield on balanced input lines Tip Positive should be grounded at one end only usually the signal source Ring Negative Sleeve Ground 13 14 Balanced 1 4 TRS amp XLR Input Connectors These connectors accept input signals on balanced TRS and XLR input plugs See the figure at the left for information on polarity Connectors for each nel are in parallel the unused connectors may be used for loop through con nection to other amplifiers NOTE Unbalanced Tip Sleeve plugs may be used with the balanced TRS Tip Ring Sleeve connectors The ring terminal or negative input will be con 1 Ground nected to ground internally When using three pole stereo TRS connectors make 3 Negative 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 2 Positive 15 Fan Inlet Ports amp Filters Cooling air enters the amplifier through the fan inlet port
26. speaker cables make connections to both the Channel A and Channel B connectors for Stereo or Parallel Mode or to the Bridged mode connector for Bridged Mono Mode See Appendix D and the section on Mode Selection for more information NOTE on the 5 way Output Binding Post version of the CPA1800 two pairs of 5 way binding posts are provided for each channel so that paralleling of speakers is possible Never connect a hot red output to ground or to another hot red output 11 Mode Selection Switch This recessed three position switch configures the amplifier for Stereo Parallel or Bridged Mono Mode operation Amplifiers are factory configured for Stereo Mode See Appendix D and the section on Mode Selection for more information 12 Signal Ground Lift Switch The recessed signal ground lift switch factory set to the ground bottom position electrically connects signal ground to the chassis AC ground The top position lifts the amplifier s signal ground In a properly designed system for safety purposes and to minimize noise amplifiers should be connected to ground through the AC line cord Also whenever possible the signal source equipment should share the same AC ground as the ampli fier In some cases this may not be possible and a ground loop results If this happens the first step is to move the ground lift switch to the top lift position In this position the signal ground is lifted and completely i
27. t its output terminals the output relay will immediately open to prevent loudspeaker damage The Protect LEDs will light Subsonic Frequencies Built in high pass filtering provides subsonic frequency protection for each channel In addition a relay will open if excessive subsonic energy appears at the output Page 14 Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 CREST AUDIO 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 CPA Series amplifiers automatically protect speakers from DC voltages and subsonic signals For more information see the TourClass Protection section Mid and high frequency transducers compression driver in particular are highly susceptible to damage from overpowering clipped waveforms or frequencies below their rated passband When using an electron ic 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 CPA Series amplifier
28. ure 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 Read the section on Speaker Protection and always be aware of the speaker s continuous and peak power capabilities Crest Audio is not responsible for damage to loudspeakers for any reason Service and Repair In the unlikely event that your amplifier develops a problem it must be returned to an authorized distribu tor 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 contact information reach Crest Audio Inc Customer Service directly at TEL 201 909 8700 USA Fax 201 909 8744 USA Because of the complexity of the design and the risk of electrical shock all repairs should be attempted only by qualified technical personnel If the unit needs to be shipped back to the factory it must be sent in its original carton If improperly packed your amplifier may be damaged For those with Internet access please visit the Crest Audio website at http www crestaudio com Page 16 Crest Audio CPA Series Power Amplifiers Models CPA400 CPA600 CPA900 CPA1200 CPA1800 Appendices SERIES Appendix A Amplifier Specifications s CE CREST AUDIO
29. ures on the current that each amplifier will demand Make sure the mains voltage is correct and is the same as that printed on the rear of the amplifier Damage caused by connecting the amplifier to improper AC voltage is not covered by any warranty Unless other wise specified when ordered Crest amplifiers shipped to customers are configured as follows North America 120VAC 60Hz Europe 230V AC 50Hz Asia 220V AC 50Hz Australasia 240V AC 50Hz South America 120VAC 60Hz or 220V AC 50Hz Japan 100VAC 50Hz NOTE Always turn off and disconnect the amplifier from mains voltage before making audio connections Also as an extra precaution have the attenuators turned down during power up Cooling System and Requirements CPA Series amplifiers use a twin tunnel forced air cooling system to maintain a low even operating tem perature Drawn in by dual 45 cubic feet per minute CFM fans on the rear panel air flows through the cooling fins of the channel heat sinks dissipating power transistor heat then exhausts through the front panel slots The intelligent variable speed DC fans are controlled by heat sink temperature sensing cir cuits When the amplifier is turned on the fans briefly rev up then slow to an idle this indicates that the temperature sensing circuits are operating normally The fan speed increases only as required by heat sink temperatures keeping fan noise to a minimum Under extreme thermal loa
30. ustained low impedance is encountered the amplifier s output relay will open AutoRamp Protection Auto Ramp operates every time the amplifier is turned on or is reactivated after a protect condition is cor rected This exclusive Crest Audio feature gradually increases gain to the attenuator setting avoiding unnec essary stress on the loudspeakers Thermal Protection Abnormally high heat sink temperatures will engage the Protect circuit for the overheating channel only An output relay disconnects the loudspeakers until nominal temperature range is restored During this time the Protect LED will light If the power transformer gets too hot its thermal sensing circuit will dis connect both channel outputs During this time the Active LED will extinguish the Protect and Clip LEDs will stay lit and the cooling fan will continue running at low speed Normal operation resumes once the transformer cools to a safe level Short Circuit If an output is shorted i e defective speakers or crossed speaker wires the IGM and thermal circuits will automatically protect the amplifier The IGM circuit senses the short circuit as an extremely stressful load condition and attenuates the signal protecting the channel s output transistors from over current stress If the short circuit remains the load will be disconnected by the thermal protection circuitry output relay opens DC Voltage Protection If an amplifier channel detects DC voltage a
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