Audio Database

The

Marantz Model 1120 175,000yen( at the 1972 time(?))

Description
 
The Integrated Amplifier which attained simple-ization of the circuitry and aimed at the high-definition balance.

The whole page direct coupling system which adopted the differential-amplification circuitry as the top is used for a power amplifier part.
The thing of the pair was completely made in two stones of the differential-amplification stage, it acted to one as a couple of these two, the status same thermal completely was maintained, and the property excellent in one step has been acquired.
A careful phase correction, such as making temperature compensation perfect at each part using diode, or using an empty core special coil, in order not to degrade the distortion of a high region, is performed.
Moreover, the special article by joint development of a Marantz and Motorola, Inc. is adopted as a power transistor.

A protection network is the same type as Model 500, and when there is the leakage current to a speaker, the relay operates and it serves as OFF. Moreover, in order to prevent the it1 sound of the instant rush current at the time of Switchpoint ON etc. to serve also as a muting, timing is shifted by the relay until amplifier goes into perfect operating state.

The equalizer stage of a pre part has adopted a two-step stream composition, and a differential-amplification circuitry is adopted as the head and it has adopted the SEPP pure complementary circuit as a final stage.
Moreover, the inside of the feedback loop is a full hardwired connection, and has hung the negative feedback covering two steps.

A 1.0-micro F capacitor is inserted in the top of a differential circuit, an unnecessary high region component is cut, and in order to remove the it1 at the time of an equalizer change completely, the resistor of 22Mohm is inserted.

It is the stream composition of having adopted the two-step hardwired-connection type also as the tone circuitry, having had a differential-amplification circuitry in the head, and having pressed down the final stage with ± balance power source. By the scheme which gives selectivity to a negative feedback circuitry and carries out elevation descent, two steps usually consider a further feedback as a sake, an input impedance is maintained greatly, and the Output load impedance is made small.

In the filter stage, Law Hy has adopted CR type.

+ and - side makes the power source for preamplifiers the constant-voltage regulated power supply which served as the perfect ripple filter.

Almost all parts are rendered to the printed circuit board of six sheets in all, and all also of switchpoints and a rotary switch have adopted the substrate type. Moreover, the shield wire usually taken about from an input terminal to a multiple contact switch does not exist except for one place.
This is aiming at the radical breakthrough of the problem that sound changes with a product line which poses a problem with a high-class machine etc.

It changed into the usual wire wrapping method, the way of stopping a lead wire using a wire clamp is adopted, and it has the structure where each substrate can be adjusted independently even afterwards.
Moreover, the coating is given in order that the printed circuit board may also prevent an etching and breakage to a Copper foil in consideration of secular change.

Switchpoints had a switchpoint in the really required location by lengthening a shaft, and it has realized the shortest connection.

In order to prevent the induction noise from the outside, the integral shielding of the reverse side of an input terminal plate is carried out by the Copper foil.
Moreover, non-contact-ization is achieved in order to prevent mixing of dust etc. by the Austria relay [ special contact ].
Furthermore, four provide the space which enters in the center and the fist avoids the cross interferencee.

The scope out termination which can monitor the phase response of a cartridge etc. is carried.


Rating of a mode
Form Console stereo amplifier
<Power amplifier part>
Continuous rating output
(Both ch(es), 20Hz - 20kHz)
4ohm: 140W+140W
8ohm: 120W+120W
16ohm: 60W+60W
THD 0.2% or less (at the time of 20Hz - 20000Hz, and an Output power)
Cross modulation distortion 0.2% or less (at the time of 20Hz - 20000Hz, SMPTE, and an Output power)
Frequency characteristic 20Hz-20kHz±0.5dB (1W)
a power band -- the Wiz 10Hz - 40000Hz
Dumping factor 30 (8ohms)
<Pre part>
Input sensitivity Low Level:1.1mV to equal 1.1V output at Pre-Amp out
High Level:110mV to equal 1.1V output at Pre-Amp out
Input impedance Low SFT Level(Phono): 47kohm
Low SFT Level(Microphone): 47kohm
High SFT Level: 25kohm
Gain Phono Amplifier:40dB
x10/Tone Amplifier: 20dB
<Synthesis>
Equivalent Noise From magnetic phono input to Speaker Terminals
Better than 140dB below 60W (8ohm load)
Power source AC100V, 50Hz/60Hz
Power consumption 200W
Dimensions Width 390x height 133x depth of 349mm
Weight 12.2kg