User manual MCINTOSH MC303

[. . . ] Power Amplifier MC303 Owner's Manual McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 13903-2699 Phone: 607-723-3512 www. mcintoshlabs. com The lightning flash with arrowhead, within an equilateral triangle, is intended to alert the user to the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the appliance. WARNING - TO REDUCE RISK OF FIRE OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL. To prevent the risk of electric shock, do not remove cover or back. No user-serviceable parts inside. IMPORTANT SAFETY INSTRUCTIONS! PLEASE READ THEM BEFORE OPERATING THIS EQUIPMENT. 1. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat. [. . . ] Refer to figures A and B. Note: Banana Plugs are for use in the United States and Canada only. 4. Connect cables from the Balanced Outputs of the A/V Control Center or Preamplifier (Center and Surround Channels) to the MC303 BALANCED INPUTs (1-3). When connecting Loudspeakers to the MC303 it is very important to use cables of adequate size, so there is little to no power loss in the cables. The smaller the Gauge number, the larger the wire size: Loudspeaker Cable Distance vs Wire Gauge Guide Loudspeaker Impedance 2 Ohms 4 Ohms 8 Ohms 25 feet (7. 62 meters) or less 50 feet (15. 24 meters) or less 100 feet (30. 48 meters) or less 7. Connect the Loudspeaker hookup cables from a single Loudspeaker to the output terminals that match the impedance of OUPUT 1, being careful to observe the correct polarities. Output impedance connections of 2 ohms, 4 ohms and 8 ohms are provided. If the Loudspeaker's impedance is in-between the available connections, use the nearest lower impedance connection. Refer to "General Information" Note 5 on page 3 for additional information. In a similar manner, connect a Loudspeaker to OUTPUT 2 and connect the remaining Loudspeaker to OUTPUT 3. Connect the MC303 Power Cord to a live AC outlet. WARNING: Loudspeaker terminals are hazardous live and present a risk of electric shock. 12AWG 14AWG 16AWG 10AWG 12AWG 14AWG 8AWG 10AWG 12AWG 5. This McIntosh MC303 Power Amplifier is designed for 8 How to Connect How to Connect for Left, Center and Right Channels Caution: The supplied AC Power Cord should not be connected to the Rear Panel of the MC303 Amplifier until after the Loudspeaker Connections have been made. For additional instruction on making Loudspeaker Connections contact your McIntosh Dealer or McIntosh Technical Support. The connection instructions below, together with the MC303 Connection Diagram located on the separate folded sheet "Mc1B, is an example of a typical audio/video system. Your system may vary from this, however the actual components would be connected in a similar manner. For additional information refer to "Connector and Cable Information" on page 4. For Remote Power Control, connect a power control cable from the A/V Control Center or Preamplifier Power Control Out to the MC303 POWER CONTROL IN. Connect a second power control cable from the MC303 POWER CONTROL OUT to the Left and Right Surround Channel Power Amplifier Power Control In. Connect cables from the Balanced Outputs of the A/V Control Center or Preamplifier (Left, Center and Right Front Channels) to the MC303 BALANCED INPUTs (1-3). Note: An optional hookup is to use the UNBALanced INPUTS with unbalanced cables instead of balanced. However, both type of connections for a given Input should not be used at the same time. 6. Prepare the Loudspeaker Hookup Cables that attach to the Amplifier by choosing one of the methods below: Bare wire cable ends: Carefully remove sufficient insulation from the cable ends, refer to figures 1, 2 & 3. If the cable is stranded, carefully twist the strands together as tightly as possible. Note: If desired, the twisted ends can be tinned with Figure 2 Figure 3 Figure 1 solder to keep the strands together, or attach spade lug and/or banana connector. Note: The remaining Amplifier Loudspeaker Terminals should not be connected to another Loudspeaker. Spade lug or prepared wire connection: Insert the spade lug connector or prepared section of the cable end into the terminal side access hole, and tighten the terminal cap until the cable is firmly clamped into the terminal so the wires cannot slip out. Banana plug connection: Insert the banana plug into the hole at the top of the terminal. [. . . ] The audible distortion is unpleasant to hear, but the inaudible ultrasonic distortion is also undesirable, since it can Input Test Signal damage valuable loudspeaker system tweeters. You will never experience the harsh and damaging distortion due to clipping. The Power Guard circuit is a waveform comparator, monitoring both the input and output waveforms. Under normal operating conditions, there are no differences between Figure 17 14 the shape of these waveforms. [. . . ]