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Appendix C

Crest Audio CA Series Power Amplifiers

Models CA2, CA4, CA6, CA9, CA12, CA18

Stranded Cable Lgth.
(m) 

2

5

10

30

Wire Gauge (mm

2

)

0.3

0.5

0.75

1.5

2.5

4

0.5

0.75

1.5

2.5

4

6

0.5

0.75

1.5

2.5

4

6

0.75

1.5

2.5

4

6

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

1.74

1.09

0.73

15.5%

8.2

5.1

3.2

2.2

1.31

Power Loss
(4 ohm load)

5.6%

3.4

2.3

1.16

0.70

0.44

8.2%

5.6

2.9

1.74

1.09

0.73

15.5%

10.8

5.6

2.9

1.74

1.09

0.73%

15.5

9.8

6.3

4.3

2.6

Power Loss
(2 ohm load)

10.8%

6.7

4.5

2.3

1.39

0.87

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

18.2

12.0

8.2

5.1

Appendix C - Wire Gauge Chart (Metric)

Summary of Contents for CA

Page 1: ...MANUAL PROFESSIONAL POWER AMPLIFIERS Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier Professional Power Amplifier ...

Page 2: ... used in an extremely dusty or smoky environ ment the unit should be periodically blown free of foreign matter 14 Do not remove the cover Removing the cover will expose you to potentially dangerous voltages There are no user serviceable parts inside 15 Connecting amplifier outputs to oscilloscopes or other test equipment while the amplifier is in bridged mode may damage both the amplifier and test...

Page 3: ...cting Outputs Mode Selection Stereo Parallel Bridged Mono Connections TourClass Protection Features User Precautions Speaker Protection Recommended Speaker Cabling Maintenance User Responsibility Service and Repair 5 5 5 6 7 8 9 9 9 10 10 10 12 14 15 15 15 16 16 16 Power Amplifier Owner s Manual Table of Contents Appendix A Specifications Appendix B CA Block Diagram Appendix C Wire Gauge Charts Ap...

Page 4: ...wer Amplifier Front height 3 5 89mm CA2 9 Front View Rear Side Views Front width 19 483mm Note see Appendix E for detailed CA18 rear panel drawings A A B AB A 1 3 2 B A B A A A B B A B 5 25 133mm CA12 CA18 3 5 89mm CA2 CA4 CA6 CA9 17 9 437mm 19 483mm to rack ears 1 375 35mm 18 457mm A A B AB A 1 3 2 A A B B A B B A A B 5 way binding post version shown Speakon version shown CA2 9 CA12 CA18 ...

Page 5: ... 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 CA Series amplifier is subjected to punishing extremes in the most demanding fixed or mobile sound rein forcement applications U...

Page 6: ...o 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 i...

Page 7: ...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 amplifier 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 ...

Page 8: ...igured as Pin 2 hot On models CA2 CA4 CA6 CA9 and CA12 an internal jumper makes it possible to alter the amplifier to Pin 3 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 CA18 an external XLR polarity switch is featured See Appendix E Input Sensitivity The CA Series amplifiers ...

Page 9: ...nel 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 circuits 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 ...

Page 10: ...dio input to another amplifier input For more information see the sections on Balanced 1 4 TRS 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 CA18 two pairs of 5 way bind ing posts are provided...

Page 11: ... channel alone Signal is applied to the Channel A input only Both attenuators are used to control sig nal 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 Bri...

Page 12: ... 2 A A B B A B B A A B A A or A A A A B AB A 1 3 2 A A B B A B B A 643 106 A B A A A or Bridged Mono Stereo Mode Connections 5 Way Output Binding Posts NOTE the Binding Post version of the CA18 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 ...

Page 13: ...IN 1 2 1 2 1 A A B AB A 1 3 2 B A NL4FC B A A B A A B B A A or A A Speaker to PIN 1 Speaker to PIN 1 2 1 2 1 A A B AB A 1 3 2 B A NL4FC B A A B A A B B A A or Speaker to PIN 1 Speaker to PIN 2 2 1 2 1 Bridged Mono Stereo Mode Connections Speakon Output Connectors Parallel Mode Connections Speakon Output Connectors Bridged Mono Mode Connections Speakon Output Connectors ...

Page 14: ...urned 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 rang...

Page 15: ...ter 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...

Page 16: ...ier 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 Ser...

Page 17: ...Appendices ...

Page 18: ...0A 18 0A 2630 BTU hr 3713 BTU hr 3 5 x 19 x 18 89 x 483 x 457mm 49 lbs 22 24 kg 44 lbs 19 97 kg 5 years 600W 900W 1000W 1800W 2000W 550W 800W 900W 1600W 1800W 82V 116V 20Hz 20kHz 3dB 135kHz 20Hz 20kHz 84dB 0dB 0 01 0 01 700 1 60 dB 0 775V X86 5 20kΩ 10kΩ 105dB 60dB H 80 000 µF 100V 240V 50 60Hz 2 0A 8 6A 16 0A 21 0A 3250 BTU hr 4341 BTU hr 3 5 x 19 x 18 89 x 483 x 457mm 52lbs 23 60 kg 47 lbs 21 33...

Page 19: ... 2 3 PIN 2 3 JUMPER REAR PANEL SWITCH ON CA18 INVERTED NON INVERTED PREAMP PREAMP ATTENUATOR ATTENUATOR AMP FRONT END AMP FRONT END OUTPUT STAGE OUTPUT STAGE OUTPUT RELAY OUTPUT RELAY 2 3 PIN 2 3 JUMPER REAR PANEL SWITCH ON CA18 INVERTED NON INVERTED B B A A CHANNEL A CHANNEL B PREAMP INCORPORATES INPUT SENSITIVITY VOLTAGE GAIN JUMPER REAR PANEL SWITCH ON CA18 ...

Page 20: ...er 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 74 1 09 0 73 15 5 8 2 5 1 3 2 2 2 1 31 Power Loss 4 ohm load 5 6 3 4 2 3 1 16 0 70 0 44 8 2 5 6 2 9 1 74 1 09 0 73 15 5 10 8 5 6 2 9 1 74 1 09 0 73 15 5 9 8 6 3 4 3 2 6 Power Loss 2 ohm load 10 8 6 7 4 5 2 3 1 39 0 87 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 18 2 12 0 8 2 5 1 Appendix C Wire...

Page 21: ...Power Loss 8 ohm load 0 81 0 51 0 32 0 20 0 128 1 61 1 02 0 64 0 40 0 25 6 2 4 0 2 5 1 60 1 01 0 60 11 9 7 7 5 0 3 2 2 0 1 20 Power Loss 4 ohm load 1 61 1 02 0 64 0 40 0 25 3 2 2 0 1 28 0 80 0 51 11 9 7 7 5 0 3 2 2 0 1 20 22 14 6 9 6 6 2 4 0 2 4 Power Loss 2 ohm load 3 2 2 0 1 28 0 80 0 51 6 2 4 0 2 5 1 60 1 01 22 14 6 9 6 6 2 4 0 2 4 37 26 17 8 11 8 7 7 4 7 Appendix C Wire Gauge Chart Imperial ...

Page 22: ...Position Mode Selection Switch Stereo Position Chassis Ground Lift Switch Ground Lifted Position Chassis Ground Lift Switch Grounded Position Gain Select Switch CA18 XLR pin hot select switch CA18 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 ...

Page 23: ...igures 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 Refer to the specifications for input sensitivity values at optional voltage gains of X40 and ...

Page 24: ...rest Audio Inc 100 Eisenhower Dr Paramus NJ 07652 USA TEL 201 909 8700 FAX 201 909 8744 http www crestaudio com Printed in USA Choice of touring professionals B5000013 v 2 9 11 25 97 1997 Crest Audio Inc ...

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