User manual MCINTOSH MC501

[. . . ] Power Amplifier MC501 Owner's Manual McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 13903-2699 Phone: 607-723-3512 FAX: 607-724-0549 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. [. . . ] If all the components are installed in a single cabinet, a MC501 Side View quiet running ventilation fan in Custom Cabinet can be a definite asset in maintaining all the system components at the coolest possible operating temperature. Support A custom cabinet installaShelf tion should provide the following minimum spacing dimensions for cool operation. For Remote Power Control, connect a power control cable from the Control Center or Preamplifier Power Control Out to the MC501 Power Control In. Connect cables from the Unbalanced Output of a McIntosh Preamplifier or Control Center to the MC501 Unbalanced Input. Note: An optional hookup is to use balanced cables. 3. Prepare the Loudspeaker Hookup Cables that attach to the MC501 Power 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 solder to keep the strands together, or attach spade lug and/or banana connector. 4. Connect the Loudspeaker hookup cables to the output terminals that match the impedance of the Loudspeaker, 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. WARNING: Loudspeaker terminals are hazardous live and present a risk of electric shock. For additional instruction on making Loudspeaker Connections contact your McIntosh Dealer or McIntosh Technical Support. 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. Attach the supplied Terminal Connections Cover with the three Mounting Screws (6-32 x 1/4 inch Phillips Head) to the Rear Panel of the MC501 Amplifier. Refer to figure 9. Note: There are two openings on the cover allowing for the Loudspeaker's Cable to exit the MC501. 6. Connect the MC501 power cord to an active AC outlet. Terminal Connections Cover Cable Openings Cover Mounting Screw Locations Figure 9 Cover Mounting Screw Location 8 How to Connect McIntosh MX134 A/V Control Center MC501 Top Rear View To AC Outlet 4 ohm Loudspeaker Caution: The Loudspeaker Negative Connections are above chassis ground. Do not combine any connections together, ground them or connect with another MC501. 9 Front Panel Displays and Controls METER indicates the Power Output of the amplifier POWER GUARD LED lights when the amplifier POWER GUARD circuit activates Remote On Indicator lights when the amplifier is in the Remote TurnOn Mode METER Switch selects the display modes of the Power Output Meter POWER Switch Turns AC power On/Off, or On/Remote 10 How to Operate How to Operate Power On To have the MC501 automatically turn On or Off when a control center turns on or off, rotate the power switch to the remote position. For manual operation, rotate the power switch to the On or Off position as desired. Refer to figure 10. Note: There must be a power control connection between the MC501 and Figure 10 the McIntosh Control Center, in order for the remote power turn-on to function. peaks are reached, the meter pointer will very slowly return to its rest position or lower power level. The decay rate is approximately 6dB per minute. Note: The MC501 Power Output Meter indicates the actual wattage delivered to the Loudspeakers by responding to the combination of current and voltage output. Input Mode Switch The Input Mode Switch, which is located on the Top Rear Panel of the MC501, allows selection of either the Balanced or Unbalanced Input. Refer to figure 13. Meter Selection Rotate the meter mode switch to select the meter operation mode you desire. Lights Off - Meter lights are turned off and the meter will continue to indicate the power output. Watts- The meter respond to all the musical information being proFigure 11 duced by the amplifier. They indicate to an accuracy of at least 95% of the power output with only a single cycle of a 2000Hz tone burst. Hold - The meter pointer is locked to the highest power peak in a sequence of peaks. [. . . ] 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 Figure 19 between the shape of these waveforms. If an amplifier channel is overdriven, there will be a difference between the two signal waveforms. [. . . ]