Audio Database

PMA-1090
Commentary

Pre-main amplifier with Mos super optical ClassA circuit.

A large toroidal transformer is used in the power supply to bring out the large output capacity of the power transistor.
Unlike conventional transformers, toroidal transformers consist of a toroidal ring core with a coil wound around it, and have excellent characteristics such as stable supply of current, leakage flux, and vibration prevention.

The power amplifier uses a MOS super-optical Class A circuit that adds a MOS-FET to the New Super-optical Class A circuit.
The Inverted Darlington driver equipped with a MOS-FET and bipolar transistor in the driver stage makes it possible to dramatically increase the bias current supplied to the driver stage. Class A operation range can be expanded, and the quality equivalent to class A operation is ensured by the new optical Class A circuit even at large signals.

The preamp section and power amplifier section are independent.
It has a separate configuration in which all circuits such as the power supply transformer and the power supply circuit are separated and independent. It suppresses the mutual interference of each block by electromagnetic wave from large current, and achieves more stable operation and higher sound quality.
In the power amplifier section, Lch and Rch are independent circuits to further eliminate mutual influence.

In order to reduce adverse effects on signals caused by wiring materials and wiring, the signal path from the input terminal to the speaker terminal is minimized.

Low-impedance volume control is used to improve the S/N ratio at the listening level.

Equipped with CD balance input.

It is equipped with a source direct switch. When on, it is possible to bypass control circuits such as tone control, balance, loudness, and subsonic.

Equipped with a phono selector that can be used with any MM/MC cartridge.

There are 2 types, PMA 1090 in black color and PMA 1090 g in gold color with side wood.

Model Rating
Type Pre-main amplifier
Power Amplifier Unit
Rated Output (20 Hz ~ 20 kHz) 180W + 180W (6 Ω)
150W + 150W (8 Ω)
Total harmonic distortion factor 0.004% (1 kHz, 75W, 8 Ω)
Dynamic Characteristics / Dynamic Power 450W (2 Ω)
350W (4 Ω)
Output bandwidth 5 Hz to 50 kHz (75W output, 0.03%, 8 Ω)
Line input frequency characteristic 4 Hz ~ 150 kHz + 0 -3dB (output 8 Ω, 1W)
Output terminal AORb : 6 Ω ~ 16 Ω
A + B : 12 Ω ~ 16 Ω
Maximum headphone output 48 mW (8 Ω)
Preamplifier Section
Input Sensitivity / Impedance Phono MM : 2.5mV/47k Ω
Phono MC : 0.2mV/100 Ω
Tape1, 2, CD, Tuner, Aux : 150mV/47k Ω (source direct off)
Tape1, 2, CD, Tuner, Aux : 150mV/10k Ω (source direct on)
Maximum Output / Rated Output 10V/150mV
Total harmonic distortion factor 0.001% (1 kHz, 1 V)
RIAA deviation 20 Hz to 50 kHz ± 0.3 dB
<General>
SN ratio (Audibility compensation A, input short circuit) Phono MM : 95 dB at 5 mV input
Phono MC : 77 dB at 0.5 mV input
Line input : 110 dB (when source direct is on)
Tone control characteristics Bass : ± 8 dB (100 Hz)
Treble : ± 8 dB (10 kHz)
Subsonic filter 16 Hz, -12dB/oct.
Loudness control characteristic +7dB(100Hz)
+6dB(10kHz)
Power supply voltage 100 VAC, 50Hz/60Hz
Power consumption 250W
External Dimensions (including legs, knobs, terminals) PMA-1090 : Width 434x Height 185x Depth 438 mm
PMA-1090G : Width 470x Height 186x Depth 438 mm
Weight PMA-1090:17.5kg
PMA-1090G:19.0kg