McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York C48 Audio Preamplifier Owner’s Manual 13903-2699 Phone: 607-723-3512 www.mcintoshlabs.
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. WARNING - TO REDUCE RISK OF FIRE OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. IMPORTANT SAFETY INSTRUCTIONS! PLEASE READ THEM BEFORE OPERATING THIS EQUIPMENT. 1. Read these instructions. 2. Keep these instructions. 3.
Thank You Customer Service Your decision to own this McIntosh C48 Audio Preamplifier ranks you at the very top among discriminating music listeners. You now have “The Best.” The McIntosh dedication to “Quality,” is assurance that you will receive many years of musical enjoyment from this unit. Please take a short time to read the information in this manual. We want you to be as familiar as possible with all the features and functions of your new McIntosh.
General Information and Connector Information General Information 1. For additional connection information, refer to the owner’s manual(s) for any component(s) connected to the C48 Audio Preamplifier. 2. The Main AC Power going to the C48 and any other McIntosh Component(s) should not be applied until all the system components are connected together. Failure to do so could result in malfunctioning of some or all of the system’s normal operations.
Introduction and Performance Features Introduction The McIntosh C48 Audio Preamplifier is one of the finest Preamplifiers ever created. The versatile Preamplifier provides connections for various input sources both analog and digital. The C48 Outputs have the ability to drive multiple Power Amplifiers. The C48 reproduction is sonically transparent and absolutely accurate. The McIntosh Sound is “The Sound of the Music Itself.
Dimensions Dimensions The following dimensions can assist in determining the best location for your C48. There is additional information on the next page pertaining to installing the C48 into cabinets. Front View of the C48 17-1/2" 44.45cm 5-3/8" 13.69cm 6" 15.24cm Side View of the C48 16-1/2" 41.91cm 14-1/2" 36.83cm 3/16" 4-13/16" 0.48cm 12.22cm Rear View of the C48 17-1/8" 43.50cm 4-5/8" 11.75cm 13/16" 2.06cm 10-9/16" 26.83cm 1-15/16" 4.92cm 13 -1/4" 33.66cm 6 2" 5.
Installation Installation The C48 can be placed upright on a table or shelf, standing on its four feet. It also can be custom installed in a piece of furniture or cabinet of your choice. The four feet may be removed from the bottom of the C48 when it is custom installed as outlined below. The four feet together with the mounting screws should be retained for possible future use if the C48 is removed from the custom installation and used free standing.
Rear Panel Connections Rear Panel Connections The identification of Rear Panel Connections for the C48 Audio Preamplifier is located on a separate folded sheet contained in the Owner’s Manual Packet. Refer to separate sheet “Mc2B” for the Rear Panel Connections.
Connecting Components Connecting Components The C48 has the ability to automatically switch power On/Off to Source Components via the Power Control connections. The Data Port Connections allow for the remote operation of basic functions using the C48 Remote Control. With an external sensor connected to the C48, remote control operation of the system is possible from another room and/or when the C48 is located in a cabinet with the doors closed.
Remote Control Push-Buttons LED illuminates during the time a remote command is sent to the C48 Switches the Trigger 1 and/or 2 Power Control Jack(s) On/Off, refer to “Setup, Power Control TRIG 1 and TRIG 2” on page 15 for additional information Selects a Disc Player, Music Server or Recorder Function. Seek Stations Up or Down the AM/FM Dial.
How to use the Remote Control How to use the Remote Control The supplied HR072 Remote Control is capable of directly controlling the functions of contemporary Source Components connected to the C48 via the Data Ports. Tuner Push-buttons Press the AM or FM Push-button to select the desired broadcast band. Press and release the Channel Up p or Down q Push-button to seek the next available station. Press and hold a Channel Up p or Down q Push-button to seek continuously from station to station.
Front Panel Displays, Controls, Push-buttons and Jack IR Sensor receives commands from a Remote Control EQUALIZER Controls increase or decrease the volume levels at the Center Frequencies of 30Hz, 125Hz, 500Hz, 2,000Hz, and 10,000Hz VOLUME Control allows adjustment of the listening level for both channels INPUT Control allows the selection of various sources for listening and recording Connection for low impedance dynamic headphones, for private listening MONO with indicator, combines the Left and Right
Setup How to Operate the Setup Mode Your McIntosh C48 has been factory configured for default operating settings that will allow immediate enjoyment of superb audio without the need for further adjustments. If you wish to make changes to the factory default settings, a Setup Feature is provided to customize the operating settings using the Front Panel Information Display. Refer to the C48 Front Panel Illustration on the previous page while performing the following steps.
Reassign Source Inputs, con’t 1. Press and hold the EQ BYPASS/SETUP Pushbutton until the Setup Mode is active. Then press the OUTPUT 2 / MENU ► Push-button to select the Setup Menu item “SETUP: SOURCE INPUT, TUNER :RCA”. Refer to figure 4. SETUP: SOURCE INPUT TUNER : RCA Figure 4 2. Rotate the INPUT Control until “CD2 : RCA” appears on the Front Panel Information Display. Refer to figure 5. SETUP: SOURCE INPUT CD2 : RCA Figure 5 3.
Setup, con’t 4. Rotate the INPUT Control until “LEVEL: SRVR _._” appears on the Front Panel Information Display. The illustration in figure 10 indicates a -2.5dB decrease in the SRVR Level to match the volume level of the CD Input. LEVEL: SRVR Min ¦¦¦¦ Figure 10 -2.5dB Max 5. Repeat step 4 for other Inputs with component sources connected until they all have the same relative volume levels.
Passthru, con’t Power Control Triggers 1 and 2 appears on the Front Panel Alphanumeric Display. Refer to figure 14. SETUP: PASSTHRU Source: BALANCED 2 Figure 14 3. Press the EQ BYPASS/SETUP Push-button to exit the Setup Mode. By default the Power Control TRIGger 1 and TRIGger 2 Outputs function the same as the MAIN Power Control Jack, switching On/Off with the C48.
Setup, con’t Comm Port Baud Rate Remote Control Codes The C48 may be remotely controlled from other equipment connected to the Rear Panel RS232C connector. The speed at which the C48 communicates (8 bit, no parity and 1 stop bit) with other equipment is adjustable from 9,600 bits per second to 115,200 bits per second. To change from the default speed of 115,200 bits per second, perform the following steps: 1. Press and hold the EQ BYPASS/SETUP Pushbutton until the Setup Mode is active.
How to Operate the C48 Power On and Off The Red LED above the STANDBY/ON Push-button lights to indicate the C48 is in Standby mode. To switch ON the C48, press the STANDBY/ON Pushbutton on the Front Panel or the (Power On) Push-button on the Remote Control.
How to Operate the C48 ance perform the following: 1. Press the TRIM Push-button repeatedly on the Remote Control until “BALANCE 0 dB” appears on the Front Panel Information Display. Refer to figure 54. Note: The Front Panel TRIM Push-button together with the OUTPUT 1/ OUTPUT 2 / ◄ MENU ► Push-buttons may also be used. 2. Rotate the VOLUME/ADJUST Control or press the LEVEL + / - Push-buttons on the Remote Control to emphasize the Right Channel (refer to figure 55) or the Left Channel (refer to figure 56).
How to Operate the C48, con’t 1. Select the desired Input Source. 2. Select “MONO/STEREO MODE, ______: Stereo” as indicated on the Front Panel Information Display. Refer to figure 63. MONO / STEREO MODE TUNER : Stereo Figure 63 3. Set the “MONO/STEREO MODE” for either STEREO or MONO. Refer to figure 64. MONO / STEREO MODE TUNER : Mono Figure 64 After approximately 4 seconds the Information Display returns to indicate the Source Selection and Volume Level.
How to Operate the C48, con’t activate the Equalizer for the currently selected Input Source press the EQ BYPASS Push-button. Note. The audio signal present at the RECORD OUT Jacks is unaffected by the Equalizer Circuitry. Trim Press the Front Panel TRIM Push-button to activate the C48 Trim Functions. Use the Front Panel OUTPUT 1/ OUTPUT 2 / ◄ MENU ► Push-buttons to select the desired Trim Fuction and then use the VOLUME/ADJUST Control to vary or make changes. Refer to figure 50.
How to Operate the C48, con’t The illustration to the right shows the fundamental frequency range of acoustical musical instruments and the human voice. It also shows the range of adjustment of frequencies for each of the Equalizer Controls of the C48 at the +6dB and -6dB points.
How to Operate the C48, con’t SOURCE: CD 15% SILENT Figure 73 USB Input Operation with a Computer The C48 USB-D/A Input provides the capability to playback music from a computer, when the computer is connected to the rear panel USB D/A connector. The C48 USB Input is compatible with both PC Computers using Microsoft® Windows® (XP with Service Pack 3, Vista with Service Pack 1 and Windows 7) and the Apple® Macintosh® Computers using OS-X with the latest update.
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Specifications Specifications Frequency Response +0, -0.5dB from 20Hz to 20,000Hz +0, -3dB from 15Hz to 100,000Hz Input Impedance High Level, 22K ohms unbalanced, 44k ohms balanced Phono MM, 47K ohms; 50 to 750pF, in 50pF steps Phono MC, 25, 50, 100, 200, 500 or 1,000 ohms; 100pF Total Harmonic Distortion 0.002% from 20Hz to 20,000Hz Rated Output (Main) 2.
Packing Instructions Packing Instructions In the event it is necessary to repack the equipment for shipment, the equipment must be packed exactly as shown below. It is very important that the four plastic feet are attached to the bottom of the equipment. This will ensure the proper equipment location on the bottom pad. Failure to do this will result in shipping damage. Use the original shipping carton and interior parts only if they are all in good serviceable condition.
McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, NY 13903 www.mcintoshlabs.com The continuous improvement of its products is the policy of McIntosh Laboratory Incorporated who reserve the right to improve design without notice. Printed in the U.S.A. McIntosh Part No.