
Marantz PM-4 |
74,800yen(around the 1980 time) |
The form of the external heat sink adopted by "#14", "#15",
and "MA-5" is adopted, and it is an Integrated Amplifier in which
a Class-A / AB class change is possible.
Good dual FET of the pair property was
adopted as the input stage of a power amplifier part, and the property failure
by an impedance variation is prevented with the source follower stream
composition. Moreover, both a Class-A and AB class can be enjoyed by switching
the bias current of an output stage.
A super high ft transistor with a
cut-off frequency of 90MHz is adopted as a power element, and switching
distortion is suppressed to the relative minimum.
By adoption of the
external heat sink, it is the design which can always be kept at around 60
degrees C below one-half to the operating temperature of a transistor being
usually around about 150 degrees C.
The Low-TIM design which was
consistent from the power amplifier part to the control part is carried out.
A nakedness property is improved by original 2 pole phase compensator,
the amount of prevention NF is low stopped for an open loop gain to 26dB
with 64dB, and the reduction of the TIM in a RF area is aimed at.
The phone amplifier part serves as a low-noise high gain type which MC cartridge can
direct connect by original Low-TIM design.
Moreover, the thing of a
low-impedance is selected carefully especially for the element which sets up a
RIAA curve, and the SN ratio on Hearing impression is raised.
The oxygen-free-high-conductivity-copper line of a tin coating is adopted as output cables, such as a power circuit and a speaker. Furthermore, the twice as many ordinary code of 10A as this is adopted as a power cord.
Moreover, shortening of the product line is attained with devising a construction.
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.JPG)
Form |
Stereo Integrated Amplifier
|
Output power (20Hz - 20kHz, both channel drive) |
AB class: 60W+60W (8ohms)
Class-A:
15W+15W (8ohms) |
THD (20Hz - 20kHz) |
0.015% (at the time of an 8-ohm load
intensity and an Output power) |
Cross modulation distortion (60Hz:7kHz=4:1)
|
0.015% (at the time of an 8-ohm load
intensity and an Output power) |
Frequency characteristic |
20Hz-20kHz+0 -0.3 dB
5Hz-100kHz+0 -2 dB
|
Dumping factor (an 8-ohm load intensity,
1kHz) |
70 |
Input sensitivity/impedance |
Phono1, 2 man-month:2.5mV /, 47kohm
Phono1 MC: 200 microvolts/100 ohms
Tape, Tuner, AUX:150mV/25kohm
|
RIAA deflection |
20Hz-20kHz±0.25dB |
SN ratio (IHF-A) |
Phono MM:84dB
Phono MC:64dB
Tape,
Tuner, AUX: 104dB |
Tone control |
Low-pass: ±10dB (100Hz)
High region:
±10dB (10kHz) |
Phono maximum permissible input (1kHz)
|
MM:330mV
MC:25mV |
Supply voltage |
AC100V, 50Hz/60Hz |
Power dissipation (Electrical Appliance and
Material Control Law) |
150W |
Dimensions |
Width 416x height 117.5x depth of 334mm
|
Weight |
9.5kg |
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