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. It has a serial number located on the rear panel of the chassis. Record that serial number here: Serial Number The model, serial number and purchase date are important to you for any future service. [. . . ] 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. Select the position that sounds best to you. 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. Non-percussive music and voice require slower speed. 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. The circuits can by switched to function as an expander or as a compressor. Expansion increases the dynamic range of program material. This can be used to restore compressed material from tape recordings, records, or radio broadcasts. Compression decreases the dynamic When the COMPANDOR selector is in the EXPAND position, the RATIO control is used to select the amount of expansion. Full counterclockwise rotation corresponds to a ratio of 1. 0. This means that the dynamic range of the expander output is the same as the dynamic range of its input. Set the VOLUME control to a normal listening level. No change in dynamic range will be heard. As the RATIO control is increased clockwise, however, the output dynamic range becomes greater than the input. [. . . ] 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. If no processor is connected the signal passes directly through the jacks. An equalizer amplifier with unity gain follows next. [. . . ]