McIntosh MX 117 Brochure

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MX 117 F 1. FM AFL AUTOMATIC FREQUENCY LOCK The Automatic Frequency Lock is a patented Mclntosh circuit that activates when you tune to the center frequency of an FM station. A varacter diode fine tunes the tuner with a correction volt- age from the AFL circuit. When the center ON -station vertical LED indicator lights, the AFL cir- cuit is in operation and the tuner stays locked to the signal. There will be no drift from this accu- rate tuning, insuring minimum distortion and best overall FM performance. 2. ELECTRONIC FET ANALOG INPUT SWITCHING All critical input switching is done electronically using field effect transistor analog switches. The front panel selector simply switches small amounts of control DC voltage which turn the FET analog switches on or off. Since the FET analog switches are located near the input jacks, the length of interconnecting leads is much shorter. This design eliminates switching noise as well as frequency loss caused by the longer signal leads necessary in conventional circuits. 3. HEADPHONE-OUTPUT AMPLIFIER The built-in headphone amplifier is capable of driving a pair of dynamic headphones with less than 0.02% harmonic distortion. Because of its extremely low distortion and power capability, it is also the main preamplifier output. 4. TRI-FREQUENCY PROGRAM EQUALIZER Three separate controls allow the balance and re- sponse of musical information to be adjusted with far more flexibility than with conventional tone controls. The center frequencies of the con- trols are 30 Hz, 750 Hz and 10 kHz. Plus and minus 12 dB of control is available. Use of the program equalizer controls does not affect in the slightest the low noise, low distortion performance of the tuner-preamplifier. When the equalizer controls are in their center detent or flat position, their ac- tion is neutral and response of the tuner-pre- amplifier is absolutely flat. 6. PRECISION TRACKING VOLUME CONTROL The volume control manufactured for Mclntosh Laboratory is a step attenuator which has track- ing accuracy within 1 dB throughout its entire range. Such extremely accurate matching is achieved through electronically controlled trimm- ing of the resistance material deposited on pairs of miniature printed circuits. Tracking accuracy and quiet performance are permanently maintain- ed. Use does not affect performance as in ordin- ary volume controls. 5. TRUE LOUDNESS COMPENSATION The MX 117 active circuit loudness control is con- tinuously variable with constant midrange gain and operates independently of the volume con- trol. The loudness contour is accurately modeled after the Fletcher Munson family of "Equal Loud- ness" curves. Use of this control restores proper perceived frequency response at even the softest listening levels.

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EATURES 7. ELECTRONIC FET RF SELECTIVITY SWITCHING A back panel switch gives additional FM RF selec- tivity for best performance in areas with extremely strong station signal strengths. This switch feeds a control DC voltage to PIN semiconductor diodes which electronically perform the RF switching functions. for a superheterodyne tuner. The AM RF amplifier circuit has constant selectivity, constant sensitiv- ity and high image rejection across the complete AM band. In addition there is no loss of audio fre- quency response at the low end of the band. No conventional AM circuit can offer all these features simultaneously. These advanced AM per- formance characteristics of the MX 117 bring about a re-discovery of AM listening. INTEGRATED CIRCUIT OPERATIONAL AMPLIFIERS Both the magnetic phono and the equalizer ampli- fier stages utilize new high technology integrated circuit operational amplifiers. Noise factors are incredibly low and distortion levels are at or below the limits of the best present day test equipment. WHY YOU SHOULD OWN MclNTOSH - After thirty years of existence, amplifier clinics held all over North America have shown most Mclntosh instruments produced, regardless of age, are still in use today. - Used Mclntosh instruments enjoy the highest re- sale value of any products in the home music field. - Since its beginning in 1949, Mclntosh Laboratory remains under the same management. More than 58 competitors have come and gone during the same period. AUTOMATIC STEREO NOISE SUPPRESSION A new third generation phase locked loop stereo decoder incorporates a unique variable stereo separation - noise reduction control circuit. This circuit operates from the IF amplifier signal strength detector. When listening to weak or dis- tant FM stations, optimum stereo separation and signal to noise ratio is automatically provided. You get a smooth transition between stereo and mono depending on the prevailing signal condi- tions. This means that with the Mclntosh MX 117 you always get the most noise-free reception of weaker stereo signals. Since this circuit automat- ically adjusts in varying amounts, you never hear the abrupt switching present in conventional cir- cuits. UNIQUE AM TUNER SECTION The AM circuit in the MX 117 is unique in design - Mclntosh instruments have always been designed for long life with low maintenance cost and high quality performance. - Mclntosh dedication, not only to improvements but also to fundamentals, has justified many patents on refinements as well as basic circuit structures. - Mclntosh invests more on a percentage basis in research and test equipment than any of its com- petitors.