What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakersare used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

H.H. Scott '59

Marantz model 18 (1968)

The model 18 Solid-State Stereophonic FM Receiver.

Now - the eloquent "Sound of Marantz" components in a single unit. In the Model 18 - Marantz introduces, for the first time, a solid-state FM Stereo Multiplex Tuner, Stereo Preamplifier and Stereo Power Amplifier - all combined on a single chassis. Styled in sleek elegant lines, it is an "FM stereo sound center" that will fill your home with stunning experiences in stereophonic listening. The Model 18 features outstanding stereo control flexibility not normally found in a complete receiver. In addition to separate bass and treble controls for each channel, there are inputs for two stereo tape recorders (one in the rear for permanent connection, and one in front tape dubbing from an external recorder), two inputs for stereo phonographs, a stereo headphone output, a switch for selection of multiple speaker system combinations, plus a multitude of other switching and control conveniences. With the Model 18 you not only enjoy the traditional unsurpassed quality and flexibility of Marantz components, but also inspired innovation in circuitry design - whichprovides cleaner sound than you've ever heard before. Weak FM stations are received without being swamped out by strong stations, and powerful stations are received without distortion. It is now easy to "lock in" tightly on one station closed adjacent to another without fear that the adjacent station will interfere with the one you want. The Model 18 attains this sharp selectivity through the use of modified Butterworth filters that couple the four amplifiers in the IF stages. Absolute tuning accuracy through the built-in oscilloscope is an exclusive feature of Marantz tuners. The oscilloscope also indicates correct antenna direction for bestreception and tuners out multipath interference, as well as tuning to the maximum signal strength of each station. The oscilloscope can also be used to test for optimum stereo separation and stereo phasing of all components connected to the model 18. Selecting the proper station becomes a delighful experience with the unique silky-smooth "Gyro-Touch" tuning control (patent appliend for), through which you tune by turning the actual flywheel itself. Mounted horizontally the flywheel tunes in the direction you are seeking. Solid-state throughout, the amplifier sections are rated at 40 watt rms continuous per channel (80 watts peak) all the way from 20 Hz to 20,000 Hz. Other features of the amplifier section include direct coupled design to provide instantaneous overload recovery. There is an exclusive automatic protection circuit incorporated for both the amplifier components and speaker systems. Flawless performance was the engineering objective - flawless performance is the final result.

Features

Built-in oscilloscope - This displays incoming signals for precise tuning, strenght of signal correct antenna orientation for miniumum multipath distortion and station modulation. It may also be used for observing the degree of stereo separation, stereo phasing of all stations and other components connected through the Model 18 receiver.

Butterworth Filters - incorporated in the IF stages these assure better selectivity, lower distortion, and more than 30 dB stereo separation,even at 15 kHz. The IF stages never require realignment.

Gyro-Touch Tuning (patent applied for) - Selecting stations becomes a delighful experience with this unique control in which you rotate the actual tuning flywheel. This results in silky-smooth, ultra-low friction tuning action.

Direct Coupled - Design and protection Circuits (patent applied for) - Through these, the amplifiers recover instantaneously from overload. They also protect both amplifiers and loadspeakers against sustained overload damage caused by short circuits or other accidental misuse.

Front panel Tape Recorder Dubbing Connection - These provide convenient facilities for making tape copies with an external recorder.

Front Panel Headset Output - You can listen to stereo headsets with or without the loudspeakers playing.

Longer Dial - Because the tuning dial is longer than on most receivers you can more accurately "zero in: on a given station.

1% Resistors Used - The best resistors available, they give supremely low noise. They are used throughout the receiver in all vital circuits.

Massive Heat Sinks - These dissipate heat from the power transistor circuits, and that means longer years of use.

Electronic Time Delay Circuit - This mutes the signal to the loudspeakers for about five seconds after the unit is turned on, thus eliminating the irksome "popping" noise normally produced at that time by high power supply transistorized units.

Specifications

Rated Continuous - (RMS power outpot, per channel, both channels operating simultaneously, 20 Hz to 20 kHz): 40 watts (4 and 8 ohms); 20 watts (16 ohms)

I.M. Distortion - (SMPTE) at or below rated power = 0,2% max.

Total Harmonic Distortion - 20 - 20,000 Hz , at or below rated power = 0,2% max.

Power Bandwidth - 0,2% total harmonic distortion - 10 Hz to 30 kHz

Frequency Response - 20 Hz to 20 kHz +1/-2 dB (high level) RIAA ±0,5 dB (phono)

Input Sensitivity - (for 40 watts at 8 ohms) 100 mV at (high level), 1 mV at (phono)

Input Impedance - 100,000 ohms (high level), 47,000 ohms (phono)

Hum and Noise - Below 40 watts, 8 ohms: -80 dB (high level), 47,000 ohms (phono)

Damping Factor - 30 minimum at 8 ohms.

Stability - UnconditionaSeparation and Crosstalk - Minimum 35 dB from 20 to 20,000 Hz

FM SECTION

Noise Quieting - -50 dB at 5μV; -60 dB at 10 μV; -70 dB at 50 μV

Total Harmonic Distortion - 0,2% max. 400 Hz, 100% Mod

Frequency Response - 75 μsec DE-EMP ±0,5 dB

Multiplex Separation - 40 dB at 20 Hz; 45 dB at 1 kHz; 31 dB at 8 kHz; 30 dB at 15 kHz

38 kHz Suppression - 60 dB

67 kHz Suppression - 65 dB

PHYSICAL MEASUREMENTS

Dimensions: 18¼" wide x 16" deep x 6" high (including feet)

Front Panel Dimensions: 18¼" wide x 5¾" high

Shipping Weight: 46 lbs

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