Marantz PM-14SA

Commentary

A pre-main amplifier based on the PM-14 for Super Audio (next-generation digital audio).

The basic configuration is based on the PM-14. It uses a strong and high precision copper plated and high density zinc die-cast chassis with a phono equalizer amplifier, balance buffer amplifier, preamp, tone control amplifier, power amplifier and power supply mounted on top of it. The layout remains unchanged.

In addition to the current feedback type used in the power amplifier of the PM-14SA, we have also adopted a newly designed current feedback type in the preamplifier section. By realizing a preamplifier with high drive capability with low noise and high slew rate, we aim to ensure high speed and dynamic range of unit amplifiers for next-generation digital audio.
As for the circuit configuration, a voltage amplification module with adjustable HDAM with DC offset adjustment is adopted at the first stage. Impedance conversion is performed by the FET buffer, and current feedback is injected into it. This realizes high S/N ratio and low output impedance.

The power amplifier section uses a current feedback type and reduces the feedback impedance to reduce the phase compensation and realize a high-speed amplifier. This method ensures stability against load fluctuations while eliminating the choke coil in the output section, which affects sound quality, and is also advantageous in terms of S/N.
The circuit configuration is connected from the first stage where the adjustable HDAM amplifies the voltage, to the power amplifier of the 3-stage Darlington which obtains the DC amplification factor through the I/V conversion part using the current mirror circuit after the impedance conversion. The output stage is a single push-pull type with a multi-emitter bipolar transistor of Pc = 200W. In this circuit, 100% DC feedback is applied to the first stage and the DC offset adjustment of the adjustable HDAM is carried out to eliminate the DC servo by the active element which causes a problem in S/N, etc. by adjusting the DC offset of the adjustable HDAM.
The power transistor is set on a large heat sink via a copper cover for vibration isolation / shielding.

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.
A unique noise killer element is inserted between the windings of each rectifier circuit to absorb high-frequency noise during rectification.

Equipped with an NF-type phono equalizer amplifier for MC/MM cartridges.
The first stage uses the latest adjustable HDAM (high-speed voltage amplifier module) with low-noise FET, and the output uses a high-gain, high-slew rate audio OP amplifier.

In the balanced buffer amplifier, the impedance is converted by the voltage follower of the OP amplifier, and then mixed by the same OP amplifier to cancel in-phase components such as external noise over a wide band, taking advantage of balanced transmission.

A logic relay system is used for switching between input and recording output.
The relay uses a highly reliable sealed type for the communication industry.

All unbalanced input terminals are gold-plated. Especially for CD input terminals, wide-pitch machined terminals are used for high-grade cables.
The speaker terminal is made by WBT of Germany, and it is compatible with banana plug, Y lug and thick cable.

Equipped with an input / output terminal and a selector switch for independent use of a preamplifier and power amplifier.
In consideration of the use of active woofer, the pre-out terminal is designed to be in the output state even when integrated.

Wireless remote control is included.

Model Rating

Type	Pre-main amplifier
Input / output terminal	Line input : 4 systems Balance input : 1 system Tape input / output : 2 systems Phono input : 1 system Pre-Out and Power-In : 1 system each Speaker output : 2 channels Headphone output : 1 system
Rated Output (20 Hz to 20 kHz, when both channels are driven)	100W + 100W (8 Ω) 160W + 160W (6 Ω) 200W + 200W (4 Ω)
Total harmonic distortion factor (20 Hz to 20 kHz, both channel drive, 8 Ω load)	0.008%
Intermodulation Distortion Factor (SMPTE)	0.008%
Output bandwidth (8 ohm load, 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 20 kHz)	180
Input Sensitivity / Impedance	Phono MC : 270 μ V/100 Ω Phono MM : 2.4mV/47k Ω High level : 250mV/10k Ω Main in : 1.6V/100k Ω
Phono maximum allowable input (1 kHz)	MC:10mV MM:100mV
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:115dB
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)
AC outlet	Switched : 2 lines Unswitched : 1 line
Maximum external dimensions	Width 458x Height 166x Depth 464 mm
Weight	23.0kg
Attachment	Wireless Remote Control (RC-17PM)