User manual MCINTOSH MAC4200

[. . . ] VARIOUS REGULATORY AGENCIES REQUIRE THAT WE BRING THE FOLLOWING INFORMATION TO YOUR ATTENTION. PLEASE READ IT CAREFULLY. WARNING: TO PREVENT FIRE OR SHOCK HAZARD, DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE. CAUTION; TO PREVENT ELECTRIC SHOCK DO NOT USE THE POLARIZED PLUG ON THIS UNIT WITH AN EXTENSION CORD, RECEPTACLE OR OTHER OUTLET UNLESS THE BLADES CAN BE FULLY INSERTED TO PREVENT BLADE EXPOSURE. The serial number, purchase date, and Mclntosh Laboratory Service Contract number are important to you for possible insurance claim or future service. Record this information here. Serial Number Purchase date Service Contract Number Upon application, Mclntosh Laboratory provides a Service Contract to the original purchaser. Your Mclntosh Authorized Service Agency can expedite repairs when you provide the Service Contract with the instrument for repair. Copyright 1986 © by Mclntosh Laboratory Inc. Contents INTRODUCTION INSTALLATION HOW TO CONNECT FRONT PANEL CONTROLS PERFORMANCE LIMITS PERFORMANCE CHARTS TECHNICAL DESCRIPTION BLOCK DIAGRAM SPECTRAL FIDELITY 3 4 Your MAC 4200 Receiver will give you many years of satisfactory performance. [. . . ] With either MONITOR pushbutton at the IN position, the program heard will be that from the tape recorders only. MONITOR. . . TAPE 1 Pushbutton OUT: The program source selected by the INPUT SELECTOR will be heard through the speakers. Pushbutton IN: Program from a tape recorder plugged into TAPE 1 IN will be heard through the speakers. MONITOR. . . TAPE 2 The functions are the same as MONITOR. . . TAPE 1. In addition, it controls the signal from a tape recorder plugged into the front panel TAPE IN jack. A recorder plugged into the front panel jacks disconnects the rear panel TAPE 2 IN jacks, automatically. The TAPE 2 OUT jacks on both front and rear panels are always connected. TAPE COPY. . . T1->T2 pushbutton in: connects the output from tape recorder 1 to the input of tape recorder 2 without affecting the program being heard from the speakers. In this position, a copy of the program on tape recorder 1 can be made on tape recorder 2. TAPE COPY. . . T2->T1 pushbutton in: connects the output from tape recorder 2 to the input of tape recorder 1 without affecting the program being heard from the speakers. In this position a copy of the tape program on recorder 2 can be made on recorder 1. When both MONITOR pushbuttons are out, you hear the program selected by the INPUT SELECTOR. 10 FRONT PANEL CONTROLS MONO The MONO pushbutton switches the audio output of the receiver from stereo mode to MONO. When the INPUT SELECTOR is in the FM position and tuned to a stereo broadcast the FM MPX light will remain on regardless of the position of the MONO pushbutton. With the MUTE pushbutton in, and when using the manual tuning knob, between station noise and weak noisy stations are suppressed. FM muting automatically eliminates between station noise when using the preset station selector feathertouch-buttons or when SCAN tuning. SPEAKERS 1, 2, and 3 When each of these pushbuttons are pressed IN, the output of the receiver is fed to the pair of loudspeakers connected to the corresponding rear panel SPEAKER push connectors. SPEAKERS 1, 2, and 3 may be selected singly, in any combination or all at once. POWER ON The red pushbutton turns the AC power on or off. (See "HOW TO CONNECT" "AUTOMATIC SYSTEM TURN ON/OFF". ) BALANCE AND LOUDness: The BALANCE and LOUDNESS controls are concentric. Adjusting the BALANCE control (large outer knob) adjusts the volume of the channels relative to each other and does not change the overall volume of sound in your listening room. LOUDness: After setting the VOLUME control for the desired listening level, adjust the LOUDness control for the preferred compensation. Adjusting the LOUDness control will not affect the overall volume of sound in your listening room. The LOUDness control (small center knob) contours the frequency response to compensate for the hearing characteristic of the human ear at lower listening levels. The contour is accurately modeled after the family of "equal loudness" curves identified by Fletcher and Munson. At the fully counterclockwise detented position, the LOUDness compensation is out of the circuit, so the FRONT PANEL CONTROLS 11 response is electrically flat. As the control is turned clockwise, both bass and treble frequencies increase in the correct proportion to each other. [. . . ] The control to the transistor switch is derived from a long time constant capacitor charging network which energizes the relay approximately one second after the AC power switch is turned on. The same circuit has a short turn-off time constant which causes the relay to drop out before the receiver's main power supply has a chance to discharge. POWER SUPPLY Two high current power supplies, a positive 48 volt and a negative 48 volt DC are used to drive the output power amplifier. Four large filter capacitors, 6800 microfarads each, are used to store the large amount of energy necessary for good filtering and precise voltage regulation. A stable well regulated power supply is required for proper low frequency response and negligible low frequency distortion. 22 TECHNICAL DESCRIPTION MAC 4200 RECEIVER BLOCK DIAGRAM 23 ". . . [. . . ]