Audio Database


Marantz PM-84 125,000yen(around the 1983 time)

The Integrated Amplifier which carried the technology corresponding to digital one of the Marantz and attained high-quality sound-ization by Quarters A and AVSS.

In order to aim at coexistence of the quality at the time of the Oide power which is not clipped at the time of a high-level, either, and the Koide power which reproduces Loule Bell, a quarter A circuit is developed and it carries in PM-84.
This quarter A circuit has the structure where one fourth of the maximum output operates with a pure Class-A. And with the output beyond it, it shifts to AB class and the high power operation is enabled.
Each operation has realized the smooth shift by controlling a bias current by a high-speed switching circuit.

AVSS (auto voltage shift supply) which shifts output supply voltage according to power is carried. The power element was operated in fewest areas, such as distortion and a noise, with the optimal output supply voltage, and the high quality is realized with all power level from the Koide power to the Oide power.
Moreover, the unnecessary temperature rise at the time of low power is suppressed, and the stability is raised.

The design corresponding to a low impedance is carried out, and power is maintained even if it changes a speaker impedance to a very low value momentarily.

The direct switchpoint is carried and a high SN ratio and high speed signal transmission are made possible more by power hardwired connection.

The analog-disk play is supported with constituting Phono amplifier from a Phono customer specific IC and a dual FET.
Moreover, MC input of two positions is carried.

Fundamental part groups including a power-source part are altogether checked severely through a hearing testing, and are exchanging the part of 100 or more points.
A power-source part carries the high regulation large-sized transformer of a separate amplifier class, and the newly developed custom-made electrolytic capacitor, and also in addition to the copper chassis, has the composition of having thought the tone quality as important, such as adoption of the copper screw which attains to two thirds of all the using screws.

Sub- wood was an option.

Large-sized Power-source The

Rating of a mode
Form Integrated Amplifier
Output power 120W+120W (AB class, 8 ohms, 20Hz - 20kHz)
30W+30W (a pure Class-A, 8 ohms, 20Hz - 20kHz)
190W+190W (4 ohms, 1kHz)
Output bandwidth (8 ohms, THD 0.03%) 5Hz - 40kHz
THD (20Hz - 20kHz, 8ohms) 0.015%
Cross modulation distortion 0.015%
Frequency characteristic 20Hz-20kHz+0 -0.2 dB
Dumping factor (8ohms) 120
Input sensitivity/impedance Phono man month: 2.5mV/47kohm
Phono MC: 250 microvolts/100 ohms
Phono High MC: 2.5mV/1kohm
Tape, Tuner, Aux, compact-disk:150mV/47kohm
Output load impedance Tape out: 270ohms
RIAA deflection 20Hz-20kHz±0.2dB
SN ratio (IHF-A network) Phono MM:90dB
Phono MC:76dB
Tape, Tuner, Aux, compact disk: 100dB
Phono maximum permissible input MM:220mV
Tone control property Bass: ±10dB (100Hz)
Treble: ±10dB (10kHz)
Subsonic-Filter property 50Hz
Power source 100V, 50/60Hz
Power consumption 290W
Dimensions Width 416x height 146x depth of 410mm
Weight 18kg
Option Sub- wood WPM-84 (4,000yen)