D SEries 30 50 HEADPHONES CHANNEL 1 20 40 0 OFF IOC SIGNAL ON 20 40 50 10 LEVEL 30 CHANNEL 2 10 LEVEL 0 POWER Models: D-45 & D-75A Some models may be exported under the name Amcron.® ©1999 by Crown International, Inc., P.O. Box 1000, Elkhart, Indiana 46515-1000 U.S.A. Telephone: 219-294-8000. D Series amplifiers are produced by the Professional Audio Division of Crown International, Inc. Trademark Notice: Amcron,® Crown® and IOC ® are registered trademarks of Crown International, Inc.
3 YEAR THREE YEAR FULL WARRANTY 3 YEAR WORLDWIDE NORTH AMERICA SUMMARY OF WARRANTY The Crown Audio Division of Crown International, Inc., 1718 West Mishawaka Road, Elkhart, Indiana 46517-4095 U.S.A.
The information furnished in this manual does not include all of the details of design, production, or variations of the equipment. Nor does it cover every possible situation which may arise during installation, operation or maintenance. If you need special assistance beyond the scope of this manual, please contact our Technical Support Group. Crown Audio Division Technical Support Group Plant 2 SW, 1718 W. Mishawaka Rd., Elkhart, Indiana 46517 U.S.A.
D-45 / D-75A Power Amplifiers Important Safety Instructions 1) Read these instructions. 2) Keep these instructions. 3) Heed all warnings. 4) Follow all instructions. 5) Do not use this apparatus near water. 6) Clean only with a dry cloth. 7) Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions. 8) Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus that produce heat.
D-45 / D-75A Power Amplifiers Fig. 1.1 Front and Back Views 1 Welcome Reliability is the first thing you get with your purchase of a Crown power amplifier. The D-45 and D-75A both deliver dependable operation with a wide variety of loads. Because of their exceptional reliability, these amplifiers have become the leading choice of professionals for use in recording studios, laboratories and public facilities. You can even find them on the road.
D-45 / D-75A Power Amplifiers 2 Installation D-45 and D-75A amplifiers are designed for standard 19 inch (48.3 cm) rack mounting, or they can be stacked without a cabinet. Before mounting your amplifier, determine whether you need to change the amplifier’s internal settings for your application. tors are located on the back panel. If you are making changes to a unit that is already installed, make sure the power is disconnected and the level controls are turned down.
D-45 / D-75A Power Amplifiers Fig. 2.2 System Connection loudspeakers, you can use bridge-mono mode without actually bridging the outputs. Bridge-mono mode is like dual mode except the channel 1 input feeds both outputs, and the channel 2 output is inverted. To use bridge-mono mode without bridging the outputs, wire your loudspeakers as you would for dual mode, but invert the polarity of the channel 2 output wiring (positive goes to negative, and negative goes to positive). 2.3.
D-45 / D-75A Power Amplifiers 2.3.3 Output Connection There are many methods that can be used to prevent potential output problems, but the most important preventative measure is to use good common sense. Use Good Connectors 1. To prevent possible short circuits, do not expose the loudspeaker cable connectors. 2. Do not use connectors that might accidentally tie conductors together when making or breaking connections (for example, a standard three-wire stereo phone plug). 3.
D-45 / D-75A Power Amplifiers 3. With the unit’s top side up and the front panel toward you, locate the terminal strip toward the front of the amplifier on your right. 4. Using a soldering iron, change the appropriate jumpers for the desired operating voltage (see Figure 2.3). e to only install the appr opriate fuse: 5. Be sur sure appropriate 100 or 120 volt mains: 2 Amp type 3AG. North American 200, 220 and 240 volt mains: 1 Amp type 3AG.
D-45 / D-75A Power Amplifiers The amplifier is switched between dual and bridgemono operation with the dual/mono jumper located inside the amplifier (see Appendix A). 3.5 Fuse Replacement The unit’s input gain is 26 dB as determined by 1% precision resistors in the feedback loop. This can be changed to a sensitivity of 0.775 volts by following the instructions provided in Appendix A. The AC mains fuse is located on the back panel beside the power cord. This fuse will not blow unless something is wrong.
D-45 / D-75A Power Amplifiers 4 Specifications Note: The following specifications apply to all units in dual mode with both channels driven into 8 ohm loads and an input sensitivity of 26 dB gain unless otherwise specified. Standard 1 kHz Power: This term refers to maximum average power in watts at 1 kHz with 0.1% THD. Full Bandwidth FTC Power: This term refers to standard FTC power in watts from 20 Hz to 20 kHz with 0.1% THD.
D-45 / D-75A Power Amplifiers Input Sensitivity: Configurable for 26 dB gain or 0.775 volt sensitivity (see Appendix A). Turn-On: Minimum thumps. Power-up is instantaneous with no program delay. Output Connector: Barrier block terminals and stereo headphone jack. The headphone output is unpadded, and in parallel with the main amplifier outputs. Construction Output Impedance: Less than 15 milliohms in series with less than 3 microhenries. DC Output Offset: 10 millivolts or less.
D-45 / D-75A Power Amplifiers Crown specifications are guaranteed for three years. In an effort to provide you with as much information as possible about the power-producing capabilities of your amplifier, we have created the following power matrix. The specifications found in these tables are for 120 VAC, 60 Hz North American units and are guaranteed for three years.
D-45 / D-75A Power Amplifiers 6 Service This unit has very sophisticated circuitry which should only be serviced by a fully trained technician. This is one reason why each unit bears the following label: Your repaired unit will be returned via UPS ground. Please contact us if other arrangements are required. CAUTION: To prevent electric shock, do not remove covers. No user serviceable parts inside. Refer servicing to a qualified technician. 6.
D-45 / D-75A Power Amplifiers Crown Factory Service Information Shipping Address: Crown International, Inc., Factory Service, Plant 2 SW, 1718 W. Mishawaka Rd.
D-45 / D-75A Power Amplifiers Page 16
D-45 / D-75A Power Amplifiers Appendix A A.1 Internal Settings From the factory, your amplifier is configured for dual (stereo) operation and an input sensitivity of 26 dB gain. You may optionally configure the unit for higher-power, single-channel, bridge-mono operation. Also, the unit can optionally be set for an input sensitivity of 0.775 volts. To configure the unit for bridge-mono operation or 0.775 volt input sensitivity, the chassis of the unit must be opened.
D-45 / D-75A Power Amplifiers calculated based on a sensitivity of 0.775 volts. And although the 26 dB gain setting provides a sensitivity for each amplifier that is very near 0.775 volts, the 0.775 volt sensitivity setting is provided for applications that demand this sensitivity with a high level of precision. A Crown Service Center or a technician in the field can activate the 0.775 volt input sensitivity without voiding the warranty.
