Marantz PM-14

Commentary

This is a pre-main amplifier that has been developed by gathering the know-how of amplifier production that has been cultivated up to now such as SC-5, PM-16, PM-17, etc.

The power amplifier section uses the latest Marantz current feedback type.
In this method, phase compensation is reduced by lowering the feedback impedance, and an extremely high-speed amplifier can be realized. In addition, the amplifier is stable against load fluctuations, and the output choke coil, which is harmful to sound quality, can be removed. This is also advantageous in terms of S/N.
The first stage is voltage-amplified by a high-speed adjustable HDAM, followed by an I/V converter using a current mirror circuit after impedance conversion, and connected to a 3-stage Darlington power amplifier that can obtain a DC amplification factor. The output stage is single-push-pull with a Pc = 200W multi-emitter bipolar transistor.
A 100% DC feedback is applied to the first stage, and by adjusting the DC offset of the adjustable HDAM, the DC servo due to active elements, which is a problem in S/N, etc., can be eliminated.

The power transistor is mounted on a large heat sink with sufficient space through a copper cover that serves as both vibration isolation and shielding.

The preamp section uses Marantz's original 4-channel active volume system.
In this method, a volume is also inserted into the NF circuit of the preamplifier and linked with the input volume to continuously change the gain of the preamplifier. Since the residual noise of the amplifier is mainly generated at the first stage, the residual noise can be reduced by changing the total gain. On the PM-14, the preamplifier section has a full gain of 20 dB, but the gain can be reduced by about 14 dB, which improves the S/N ratio.
The circuit configuration uses a low-noise, high-slew rate adjustable HDAM, and the output section is equipped with a bipolar transistor diamond SEPP buffer to sufficiently reduce the output impedance. The preamplifier section can also be used independently.

The volume uses a die-cast housing for the motor clutch, and the shaft uses a Duque product made of brass, which is superior in sound quality.

The tone control amplifier uses an active filter type that uses a Bar Brown high-speed OP amplifier.
With this method, even when the low and high frequencies are raised, the rise of unwanted frequencies (ultra-low and ultra-high frequencies), which is harmful to the speaker, is suppressed, and there is no waviness in the frequency response in the flat position.

It is equipped with an NF-type phono equalizer amplifier for each MC/MM cartridge.
The first stage uses the latest adjustable HDAM (high-speed voltage amplification module) with low-noise FET, and the output uses a high-gain, high-slew rate audio OP amplifier to ensure low output impedance and sufficient gain for the MC input.

The power supply uses a 450 VA super-ring core toroidal transformer with high efficiency and low magnetic flux leakage. In addition, it is equipped with two large stress-free low-double foil filter capacitors with no sleeve.
In addition, Marantz's unique noise-killer element is inserted between the windings of each rectifier circuit to absorb high-frequency noise during rectification.

Equipped with a balanced input for CD.
For the balanced input, impedance conversion is performed with a voltage follower using a Bar Brown high-speed OP amplifier, and then accurate mixing is performed up to high frequencies using the same OP amplifier. As a result, in-phase components such as external noise are canceled over a wide band, taking advantage of balanced transmission.

The interior is based on a solid and highly accurate copper-plated high-density zinc die-cast chassis. On top of this chassis, the layout takes into account sufficient separation of left and right channels, small signal and large signal areas, rational signal flow and efficient power supply.

A logic relay system is used to provide optimum layout for switching between input and REC output.
The relay uses a highly reliable sealed type for the communication industry.

All unbalanced input terminals are gold-plated, especially for the CD input terminals, which use wide pitch machined terminals.
There are two sets of speaker terminals made by WBT (Germany). These terminals can be used with Y-lugs or banana plugs. They can also be used with thick cables for reliable mounting. In addition, they are designed so that there is no difference in sound quality. This makes it possible to use two sets of speakers or connect by wire.

Pre-in pre-out and power-in terminals allow the use of a pre-amplifier and a power amplifier independently. In integrated use, the pre-amplifier and power amplifier are designed to be connected as quickly as possible by means of a changeover switch.
Also, in consideration of the use of active subwoofer, the pre-out is designed to be output even when integrated.

System remote control is included.

Model Rating

Type	Pre-main amplifier
Rated Output (20 Hz to 20 kHz, Both Channel Operation)	200W + 200W (4 Ω) 160W + 160W (6 Ω) 100W + 100W (8 Ω)
Total harmonic distortion factor (20 Hz to 20 kHz, double-channel drive, 8 Ω)	0.008%
Intermodulation Distortion Factor (SMPTE)	0.008%
Output Bandwidth (8 ω, 0.03%)	10 Hz to 50 kHz
Frequency Response (CD, Source Direct)	5 Hz to 100 kHz + 0 -1dB
Damping factor (8 Ω, 20 Hz to 10 kHz)	180
Input Sensitivity / Impedance	Phono MC : 250 μ V/100 Ω Phono MM : 2.8mV/47k Ω High Level : 200mV/10k Ω
Phono maximum allowable input (1 kHz)	MC:12mV MM:130mV
RIAA deviation (20 Hz to 20 kHz)	+ / - 0.2 dB
SN ratio (IHF-A network, input short)	Phono MC:76dB Phono MM:90dB High Level:110dB
Tone control	Bass : ± 8 dB (100 Hz) Treble : ± 8 dB (10 kHz)
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	300W (Electrical Appliance and Material Control Law)
Maximum external dimensions	Width 458x Height 166x Depth 464 mm
Weight	23.0kg
Attachment	Wireless Remote Control (RMC-17PM)