User manual MCINTOSH C33

[. . . ] THE MclNTOSH C 33 SOLID STATE STEREO PREAMPLIFIER Reading Time: 43 Minutes Price $2. 00 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. The Mclntosh you have purchased is a Model C 33. Record that serial number here: Serial Number The model, serial number and purchase date are important to you for any future service. Record the purchase date here: Purchase date Upon application, Mclntosh Laboratory provides a Three-Year Service Contract. [. . . ] Here are some suggestions from which to start. Problem Deep bass to weak All bass weak Voice reinforcement Hum on program Violins, trumpets dull Cymballs not audible Equalizer Correction Raise 30 Raise 30 and 150 Lower 150 and raise 500 Reduce 30 and 150 Raise 1500 Raise 10 K range. It can be used for making tape recordings or for listening to background music. In this way you can make your own recordings using compression and then play them back using expansion. The concentric COMPANDOR and RATIO controls are located on the front panel. The LEVEL MATCH and SPEED selector are located on the C 33 top panel. COMPANDOR SELECTOR The EQUALIZER FREQUENCY controls can be switched to either the LISTEN or RECORD program lines by the RECORD EQUALizer pushbutton. Using the equalizer will not influence the behavior of the COMPANDOR. BALANCE AND LOUDNESS The B A L A N C E and LOUDNESS controls are concentric. The BALANCE control (large outer knob) adjusts the volume of the channels relative to each other. L-LEFT. . . turning the control to the left accents the left channel by reducing the right channel output. R-RIGHT. . . turning the control to the right accents the right channel by reducing the left channel output. LOUDNESS The outer COMPANDOR knob can be set to EXPAND, OFF, or COMPRESS. When the COMPANDOR switch is in EXPAND or COMPRESS, a red light will appear above Listen or RECord at the COMPANDOR pushbutton. In the center OFF position, the Compandor System is switched out of the circuit and the lights will be out. When the Compandor is not used, the selector should be placed in the OFF position. RATIO CONTROL The inner RATIO knob is used to control the amount of expansion or compression. LEVEL MATCH The LOUDNESS control (small center knob) provides a frequency response contour which compensates for the behavior of the human ear at lower listening levels. This contour is accurately modeled after the family of "equal loudness" curves identified by Fletcher and Munson. At the fully counterclockwise detented FLAT position, the loudness contour is electrically flat. As the control is turned clockwise, both bass and treble frequencies increase in the correct proportion. The contour is not affected by different settings of the VOLUME control. After setting the VOLUME control for the desired listening level, adjust the loudness control for the preferred compensation. COMPANDOR SYSTEM The LEVEL MATCH control on the top panel is used to restore the listening level when the expander or compressor is switched into the circuit. SPEED The SPEED selector on the top panel is used to control how fast the Compandor System responds to signals. By switching from FAST to NORMAL to SLOW, a more gradual rate of change in volume can be heard. If music with percussive instruments is used, NORMAL or FAST can provide very attractive sound. At the FAST speed the Compandor System follows changes quickly but will track low frequencies less accurately. At SLOW speed the low frequency tracking is accurate but the system will respond more slowly. The NORMAL position is best suited for most program material. USING THE COMPANDOR AS AN EXPANDER The Mclntosh Compandor System can be used to control the dynamic range of program material. [. . . ] It includes band shaping, logarithmic conversion, full wave rectification, level setting, expansion or compression ratio regulation, attack timing, and DC amplification. The resulting processed voltage controls the gain of the VCA to cause logarithmic gain expansion when expanding the program, or the opposite, logarithmic gain compression when compressing the program. MONITOR AMPLIFIER The record program signal from the Record input switch goes first through a unity gain amplifier and then to the Compandor switching where the Compandor can be inserted into the record program path. These jacks, like the Listen External Processor jacks, have switching contacts so that the signal passes through when there are no plugs in the jacks. Therefore, if an External Processor is used, the Record program leaves the C 33 through the External Processor "to" jack and returns via the "from" jack. [. . . ]