User manual CROWN DC-300A

[. . . ] Other trademarks are the property of their respective owners. K80002D9 5/96 YEAR 3 THREE YEAR FULL WARRANTY 3 YEAR WORLDWIDE SUMMARY OF WARRANTY The Crown Audio Division of Crown International, Inc. , 1718 West Mishawaka Road, Elkhart, Indiana 46517-4095 U. S. A. warrants to you, the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of each NEW Crown1 product, for a period of three (3) years from the date of purchase by the original purchaser (the "warranty period") that the new Crown product is free of defects in materials and workmanship, and we further warrant the new Crown product regardless of the reason for failure, except as excluded in this Crown Warranty. NORTH AMERICA SUMMARY OF WARRANTY The Crown Audio Division of Crown International, Inc. , 1718 West Mishawaka Road, Elkhart, Indiana 46517-4095 U. S. A. warrants to you, the ORIGINAL PURCHASER and ANY SUBSEQUENT OWNER of each NEW Crown product, for a period of three (3) years from the date of purchase by the original purchaser (the "warranty period") that the new Crown product is free of defects in materials and workmanship. We further warrant the new Crown product regardless of the reason for failure, except as excluded in this Warranty. [. . . ] Cables with higher density shields are better. Spiral wrapped shield is not recommended. Avoid unbalanced lines longer than 10 feet (3 meters). Keep signal and high level wiring apart. Turn off the unit before making connections. Crown is not liable for injury or damage due to overdriven components. . 1 . 05 4 40 . 01 3 Example Shown: RL = 8 ohms; R = 0. 16 ohms or D. F. = 50; S Cable Length = 50 ft. ; answer: #12 wire 2 Fig. Note the load resistance of the loudspeakers connected to each channel of the amplifier. Mark this value on the "Load Resistance" line of the nomograph. Choose an acceptable system damping factor and mark it on the "Damping Factor" line. Your amplifier can provide an excellent damping factor of 750 or more from DC to 400 Hz in Dual mode with an 8 ohm load. Always take the precaution of installing a high-pass filter on the amplifier inputs when a predominantly inductive load is used. A three pole (18 dB per octave) filter with a ­3 dB frequency of 50 Hz is recommended. (Depending on the system, it may be preferable to use a filter with a higher ­3 dB frequency. ) Such a filter can eliminate the subsonic frequency problems mentioned in Section 3. 3. 2. Another way to prevent the amplifier from activating its protection systems early and protect inductive loads from large low-frequency currents is to connect a 590 to 708 µF nonpolarized capacitor and a 4 ohm, 20 watt resistor at the output of the amplifier in series with the positive (+) lead of the transformer. This is depicted in Figure 3. 8. 4-ohm, 20-watt Resistor Use Good Connectors 1. To prevent possible short circuits, do not use loudspeaker cables with exposed male connectors. Do not use connectors that might accidentally tie two channels together when making or breaking connections, such as a standard three wire stereo phone plug. Never use connectors that can be plugged into an AC power receptacle. Avoid connectors with low current-carrying capacity. Do not use connectors with any tendency to short. + From Amplifier Output 590 to 708 µf Capacitor 120 VAC, N. P. + Inductive Load ­ ­ SOLVING OUTPUT PROBLEMS Sometimes high frequency oscillations occur which can cause your amplifier to prematurely activate its protection circuitry, resulting in inefficient operation. The effects of this problem are similar to the effects of the RF problem described in Section 3. 3. 2. [. . . ] (Contact your local Crown/Amcron representative or our office for a list of authorized service centers. ) To obtain service, simply present the bill of sale as proof of purchase along with the defective unit to an authorized service center. They will handle the necessary paperwork and repair. Remember to transport your unit in the original factory pack. We will pay the surface shipping costs both ways for warranty service to the authorized service center nearest you after receiving copies of all shipping receipts. [. . . ]