Table of Contents
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PROFESSIONAL POWER AMPLIFIERS
OWNER' S MANUAL
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Protect
Clip
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Active
Signal
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C h A
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0dB
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Protect
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Signal
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C h B
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0dB
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C h A
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0dB
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Protect
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Signal
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C h B
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Protect
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-1
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C h A
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-1
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C h B
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0dB
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Protect
Clip
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-1
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C h A
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0dB
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Clip
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-1
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C h B
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0dB
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Protect
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Signal
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C h A
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0dB
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Protect
Clip
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Signal
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C h B
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Clip
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Signal
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C h A
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0dB
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Protect
Clip
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Active
Signal
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C h B
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0dB
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Table of Contents
Related Manuals for Crest Audio HD SERIES
Summary of Contents for Crest Audio HD SERIES
- Page 1 PROFESSIONAL POWER AMPLIFIERS Protect Clip Active Signal C h A Protect Clip Active Signal C h B Protect Clip Active Signal C h A Protect Clip Active Signal C h B Protect Clip Active Signal C h A Protect Clip Active Signal C h B...
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Page 2: Important Precautions
Damage caused by connec- Crest Audio is not responsible for dam- tion to improper AC voltage is not cov- age to loudspeakers for any reason. -
Page 3: Table Of Contents
Appendix B HD Block Diagram Appendix C Wire Gauge Charts Appendix D Rear Panel Symbols - Legend Appendix E HD18 Special Functions Appendix F Warranty Information Crest Audio HD Series Power Amplifiers Page 3 Models HD2, HD4, HD6, HD9, HD12, HD18... - Page 4 17.9"/437mm (19"/483mm to rack ears) 18"/457mm 35mm CA12 5.25" • • 133mm CA18 • • See appendix E for detailed drawing and information regarding model HD18 Page 4 Crest Audio HD Series Power Amplifiers Models HD2, HD4, HD6, HD9, HD12, HD18...
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Page 5: Introduction
Crest Audio or an authorized service center, you should use only the original factory packing. Installation and Mounting Four HD Series amplifiers are 2-rack-space units: models 2, 4, 6, and 9. The HD Series models 12 and 18 are 3-rack-spaces high. All mount in standard 19-inch racks. Four front-panel mounting holes are provided on each amplifier. -
Page 6: Front Panel
Two input attenuators adjust level for their respective amplifier channels. In Bridged Mono Mode, both attenuators are used to control signal level and must be adjusted to the same setting. Page 6 Crest Audio HD Series Power Amplifiers Models HD2, HD4, HD6, HD9, HD12, HD18... -
Page 7: Back Panel
‘lift’ position, then the shield on bal- anced input lines should be grounded at one end only (usually the signal source). Crest Audio HD Series Power Amplifiers Page 7... -
Page 8: Internal Configuration And Control
Input Sensitivity The HD Series amplifiers have a standard input sensitivity of .775 Volts for rated power at 8 Ohms. Models HD2, HD4, HD6, HD9 and HD12 are fitted with an internal jumper which allows optional gains of X20 or X40. -
Page 9: Operation
Also, as an extra precaution, have the attenuators turned down during power-up. Cooling System and Requirements. HD Series amplifiers use a twin-tunnel forced-air cooling system to maintain a low, even operating tempera- ture. 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. -
Page 10: Connecting Inputs
Connecting Inputs. Use either the XLR or 1/4-inch input connectors on the rear to supply audio signals to your Crest Audio HD Series amplifier. Both connectors accept balanced and unbalanced audio connections. (The HD 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”). -
Page 11: Mode Selection
See figures on page 12 showing output connection information. Connecting amplifier outputs to oscilloscopes or other test equipment while the amplifier is in bridged mode may damage both the amplifier and test equipment! Crest Audio HD Series Power Amplifiers Page 11 Models HD2, HD4, HD6, HD9, HD12, HD18... - Page 12 Parallel Mode Connections (5-Way Output Binding Posts) • • • • Bridged Mono Mode Connections Bridged/Mono (5-Way Output Binding Posts) 643-106 • • • • Page 12 Crest Audio HD Series Power Amplifiers Models HD2, HD4, HD6, HD9, HD12, HD18...
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Page 13: Protection Features
® Protection Features Every model in the HD 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. -
Page 14: User Precautions
The amplifier’s clipping point is its maximum peak output power. At maximum peak output power, Crest Audio HD 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. -
Page 15: Maintenance
Maintenance A HD Series amplifier requires no routine maintenance other than occasional cleaning or replacement of the fan intake filters on the rear of the amplifier. These 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 periodically “blown free”... - Page 17 Appendices...
- Page 18 3 years † For full power at 4 Ohms. ‡ See table below for dealer-configurable options. Crest Audio reserves the right to make changes or improvements in manufacturing or design which may affect specification. ©1997 Crest Audio Inc. 5/21/97 HD12...
- Page 19 SWITCH PREAMP CHANNEL B OUTPUT RELAY AMP FRONT END NON-INVERTED 2 / 3 INVERTED PIN 2 / 3 + JUMPER (REAR PANEL SWITCH ON CA18) Crest Audio HD Series Power Amplifiers Appendix B Models HD2, HD4, HD6, HD9, HD12, HD18...
- Page 20 1.45 0.87 1.74 0.55 1.09 0.37 0.73 1.45 8.24% 15.5% 0.75 10.8 19.9 10.8 1.74 1.09 1.74 0.73 1.09 0.75 15.5% 15.5 18.2 12.0 1.31 Appendix C Crest Audio HD Series Power Amplifiers Models HD2, HD4, HD6, HD9, HD12, HD18...
- Page 21 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 HD Series Power Amplifiers Appendix D Models HD2, HD4, HD6, HD9, HD12, HD18...
- Page 22 Designed & manufactured in the USA by: GAIN Crest Audio Inc. Ø 40x 20x 100 Eisenhower Dr. Paramus, New Jersey 07652 USA XLR Pin + Gain Switch XLR Pin (+) Switch Appendix E Crest Audio HD Series Power Amplifiers Models HD2, HD4, HD6, HD9, HD12, HD18...
- Page 23 Three-Year Power Amplifier Warranty Warranty Information. Crest Audio Inc. warrants to the original purchaser of any HD Series Crest Audio Amplifier purchased at an Authorized Crest Audio dealer, that it will be free from defects in material and workmanship for a period of three (3) years from the date of purchase.
- Page 24 Crest Audio Inc. 100 Eisenhower Dr., Paramus NJ 07652 USA : 201.909.8700 : 201.909.8744 http://www.crestaudio.com Printed in USA C4400001 Choice of touring professionals. v. 1.2 10/22/97 © 1997 Crest Audio, Inc.