Marantz MA-9S1

Commentary

The power amplifier circuit, power supply, and feed line have been thoroughly reviewed to realize an instantaneous current supply capability approximately three times that of conventional products (compared to 150A SM-5).

In order to minimize the effect of back electromotive force, the amplifier circuit is composed of two amplifiers, 23 dB voltage amplifier (voltage amplifier circuit) and 6 dB power buffer amplifier (power amplifier circuit) with 3 parallel, push-pull and full balance configuration.

The power supply circuit for the voltage amplifier uses a choke input method that minimizes ripple components in the rectified waveform and is resistant to load fluctuations. This reduces the harmonics of the power supply and reduces noise from the primary side to peripheral audio equipment.
In addition, the noise entering from the primary side is also reduced, and combined with the Schottky diode / noise killer element, clean power can be supplied to the small-signal circuit.

The power supply section for the power buffer amplifier uses a capacitor input method with low impedance and high current supply capability. The super-ring large toroidal transformer, specially developed ultra-low impedance block capacitor, extra-thick wiring cable and thick foil substrate enable high current supply.

In order to reduce the feedback impedance of the current feedback circuit and to realize even higher speed, we have newly developed the buffer amplifier separate module HDAM SA, which is a further evolution of Marantz original HDAM, and incorporated it into the MA-9S1.
The MA-9S1 has two power buffer amplifiers and four voltage amplifiers.

It has a center power meter.

Equipped with a 6-stage attenuator.

Machined gold-plated terminals are used for unbalanced input terminals.
A speaker terminal made by WBT of Germany is installed in the speaker terminal for bi-wiring.

It uses a large extruded aluminum heat sink of approximately 7.0 kg.

Uses a 3.2mmx2 copper plated double layered bottom chassis.

Model Rating

Type	Monaural power amplifier
Rated Output (20 Hz ~ 20 kHz)	600W (4 Ω) 300W (8 Ω)
Total Harmonic Distortion Factor (20 Hz to 20 kHz, 8 Ω)	0.01%
Output Bandwidth (8 ohm load, 0.05%)	5 Hz to 55 kHz
Frequency Response (1W, 8 Ω Load)	3 Hz ~ 120 kHz + 0 -3dB
Damping factor (8 Ω, 20 Hz to 20 kHz)	200
Input Sensitivity / Impedance	Balanced : 1.7V/20k Ω Unbalanced : 1.7V/20k Ω
S/N (IHF-A network)	Balanced:120dB Unbalanced:120dB
Voltage amplification factor	Balanced:29dB Unbalanced:29dB
ATT set value	0, -3, -6, -9, -12, - ∞ dB
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	450W (Electrical Appliances and Materials Safety Act) 1200W (at 4 Ω rated output)
Maximum external dimensions	Width 459x Height 198x Depth 451 mm
Weight	35.8kg
Attachment	AC Cable