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 speakers are 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 PM-5 ESOTEC


A stereo pre-main amp with Class A or Class AB choice. In Class A it produces 20 W RMS per channel; in Class AB it gives 80 W RMS per channel.

It has a highly original low TIM design, DC concept and all stage pp circuits. The MC amp and the phono Equalizer are designed to minimize TIM. By reducing the impedance of Phono Eq elements, we have given the PM5 a signal-to-noise ratio of 86 dB. In the choice of parts, in design and in materials first priority has been given to producing superb sound. Whatever it may cost.

In PM-5, it has a whole page perfect push pull DC amplifier stream composition that TIM distortion should be banished from all the corners in amplifier, and a nakedness property is improved. Even if it does not apply a lot of NFB, the TIM and the static characteristics are improved.
In order to raise the operational stability of a power transistor, a newly developed heat-pipe scheme is adopted as a heat-dissipation organization. Since heat is drawn out of a circuitry and it cools by a radiator, a transistor can be arranged in an ideal location and simple-izing of a circuitry and a Low-noise-izing are raised. Moreover, the mass capacitor developed for audios and the powerful power transformer which was filled up with the special resin, took heat-resistant measures and was miniaturized are adopted as a power-source part. 

Especially a phone amplifier block is the low distortion and high S/N ratio design sumptuously using a transistor. And the straight DC circuitry to which phone amplifier is direct connected to the power stage is taken in, and the quality of the disk play is raised.
Furthermore, highly precise MC head amplifier and a subsonic-speed circuitry are built in phone amplifier.
A subsonic speed is used only to an equalizer and is attaining simple-ization of other functions.
A tone control carries out "the ±8dB variable" of "100Hz" which is a right-and-left standalone version which a fine balance can adjust, and the "10kHz." And adoption of a highly precise volume has realized the entire flat response at the middle point of a thumb. 

The peek power meter of a window is suddenly equipped in the center of the front panel.
It differs from the bar window, and since light emitting diode displays power on a point in a pure Class-A and AB class, clear moreover, the Direct reading of the exact output can be carried out.
Moreover, under meter, the dubbing circuitry in which a mutual sound recording is possible, and two speakers hear it from the deck to the deck, it compares, and abundant functionalities which can perform a simultaneous play, such as a speaker multiple contact switch, are incorporated. 

Specifications:
Class B Power:
2x 80W (20Hz...20kHz, 8 Ω, 0,025%THD);
2x 100W (20Hz...20kHz, 4 Ω, 0,05%THD)
Class A Power:
2x 20W (20Hz...20kHz, 8 Ω,  0,015%THD)
Bandwidth:  7 Hz...50 kHz
Frequency Response:
Aux, Tape :  5 Hz...100 kHz (+0dB, -2dB)
Riaa :  20 Hz...20 kHz (±0,2dB)
Power Bandwidth:  5 Hz...90 kHz
Intermodulation Distortion:  0,015% (8 Ω )
Damping Factor:  100 (8 Ohm)
Inputs:
Phono MM :  2,2 mV / 27 / 47 / 100 kOhm
Phono MC :  220 µV / 75 Ohm
Aux, Tape ;   150 mV / 40 kOhm
Maximum Input:
Phono MM :  220 mV (1kHz)
Phono MC :  20 mV (1kHz)
S/N Ratio (IHF-A) :
Phono MM :  86 dB
Phono MC :  70 dB
Aux, Tape :   108 dB
Power Consumption:  350 W
Dimensions:  416 x 146 x 332 mm
Weight:  13 kg.

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