Marantz PM-80

Commentary

This pre-main amplifier was developed after studying the latest digital source in addition to the traditional amplifier technology of Marantz.

In addition to a large power transformer, a special 18,000 μ Fx2 electrolytic capacitor is used for the power supply.
In addition, very thick OFC wires are used for speaker circuits and power cords.

A noise killer circuit is installed to suppress the rectification noise generated when converting AC to DC.
It blocks high-frequency noise from several hundred kHz to around 1 MHz to ensure sound quality without turbidity.
Moreover, we have succeeded in increasing the low-frequency power by lowering the primary circuit impedance of the power supply.
In addition, noise is completely eliminated by wiring and careful circuit configuration.

The power stage consists of parallel push-pull Pc-100W power transistors with high linearity, and three stage Darlington connection for higher gain.
In addition, a copper shield plate is mounted on the power transistor to suppress the radiation and vibration from the transistor and to completely eliminate the influence on minute signals.

The phono equalizer combines a low-noise FET with an audio IC to create a low-noise amplifier.
In addition, by attenuating ultra-low frequencies below 30 Hz, modulation due to low frequencies is prevented and a wider dynamic range is obtained.

We use carefully selected parts. Especially for the signal system, we use high quality electrolytic capacitors with separators made of fibrous protein fibroin of silk and mixed paper of Manila hemp.
The printed circuit board is made of paper polyester with excellent damping properties.

Equipped with a class A / class AB change-over switch that can be used separately for A-class when small output power is required and class AB when large power is required.
The voltage switching circuit is laid out near the power supply block in order to avoid the influence on the signal current, and the distance is minimized by remote control using a photo coupler for the bias switching to minimize the effect on sound quality.

It is equipped with a source direct switch which is a further development of the conventional direct switch.
Instead of a tone control defeat, it jumps through all switches and tone control circuits, such as tape monitors and processors, and feeds directly to the power amplifier through a dedicated volume.

Input terminals Line 5 and tape input / output terminals Route 3 are mounted.
It also has a built-in processor connector that can be connected to a graphic equalizer.

Model Rating

Type	Stereo pre-main amplifier
Rated Output (20 Hz to 20 kHz, Both Channels Driven Simultaneously)	Class AB : 140W + 140W (4 Ω) 120W + 120W (6 Ω) 100W + 100W (8 Ω) Class A : 20W + 20W (8 Ω)
Dynamic Power	Class AB : 340W + 340W (2 Ω) 220W + 220W (4 Ω) 170W + 170W (6 Ω)
Total harmonic distortion factor (1 kHz, 8 Ω load)	0.0008%
Intermodulation Distortion Factor (SMPTE)	0.008%
Output bandwidth (8 ohm load, 0.03%)	10 Hz to 50 kHz
Frequency characteristic	CD Source Direct : 10 Hz ~ 100 kHz + 0 -3dB
Damping factor	180 (8 Ω load, 20 Hz to 10 kHz)
Input Sensitivity / Impedance	Phono MC : 250 μ V/100 Ω Phono MM : 2.5mV/47k Ω High Level : 150mV/33k Ω
Phono maximum allowable input (1 kHz)	MC:16mV MM:160mV
RIAA deviation (20 Hz to 20 kHz)	+ / - 0.2 dB
Signal-to-noise ratio (A network)	Phono MC:75dB Phono MM:85dB High Level:105dB
Tone control	Bass : 100 Hz, ± 6 dB Treble : 10 kHz, ± 6 dB
Pwer	100 VAC, 50/60Hz
Power consumption	220W (Electrical Appliance and Material Control Law)
External dimensions	Width 454x Height 165x Depth 380 mm
Weight	17.5kg