Audio Database

PM-88SE
Commentary

Pre-main amplifier developed as a special edition of the PM-80.

Based on the concept that the power source is the basis of the amplifier, we have adopted a toroidal transformer for the power source. It is ideal as an amplifier transformer due to its excellent regulation (current supply capacity) and low natural vibration.
In addition, a custom-made large-capacity electrolytic capacitor is mounted.
OFC wires are used for speaker circuits, power cords, and internal wiring materials to ensure smooth current flow.
In addition, as a countermeasure against rectification noise, which affects sound quality even by an extremely small amount, a powerful noise-killer element is mounted, which absorbs high-frequency noise generated during rectification and realizes sound quality without turbidity.

The power amplifier section uses a power transistor with a Pc (collector loss) of 100W in parallel push-pull, and the circuit configuration is three stage Darlington connection to increase the gain.
The PM-88SE uses pure class A amplification with 20W/ch (8 Ω) output. With class AB amplification, in which the plus and minus sides of the signal are shared by separate transistors, switching distortion occurs at the moment when the transistor is turned on or off when the music signal changes from the plus side to the minus side. However, with class A amplification, since all the waves of the signal are processed by the same transistor, switching distortion does not occur as with class AB amplification, and switching distortion is suppressed.
When large power is required, it is also possible to switch to class AB amplification.
The shield plate of the OFC that fixes the power transistor reduces unnecessary radiation generated by the transistor.

The Phono Equalizer is a low-noise amplifier that combines a low-noise FET with an audio IC. Careful attention is paid to the fidelity of the low-level analog disk signal.
It also reduces the effect of analog disk warpage by attenuating the 30 Hz ultra-low band.
In addition, careful attention is paid to the selection of parts. For example, an electrolytic capacitor made of silk separator is used for the coupling capacitor, and a paper polyester substrate with excellent vibration control is used for the printed circuit board.

The case uses side die-cast to protect each circuit from internal and external vibration. Together with other anti-vibration parts, the effect of vibration is eliminated.
The chassis is entirely copper plated to prevent high frequency waves from penetrating other circuits and components.
In addition, the adoption of a 3 mm thick anti-vibration top cover suppresses vibration of the amplifier itself and reduces vibration from the outside.

Solid aluminum knob is used for both volume and selector.
It greatly reduces the effect of the volume shaft vibration, especially the volume knob does not simply attach a solid knob, but a large washer secures the volume itself.

Input is equipped with Phono 1 system (MM/MC switching), line 4 system and tape input / output Route 3.
There is also one processor input / output terminal.
The speaker terminal is equipped with two banana plug terminals.

Model Rating
Type Stereo pre-main amplifier
Rated Output (20 Hz to 20 kHz, Both Channel Drive)
For Class AB : 100W + 100W (8 Ω)
120W + 120W (6 Ω)
140W + 140W (4 Ω)
For Class A : 20W + 20W (8 Ω)
Dynamic Power
For Class AB : 170W + 170W (6 Ω)
220W + 220W (4 Ω)
340W + 340W (2 Ω)
Total harmonic distortion rate (20 Hz to 20 kHz, 8 Ω load) 0.008%
Intermodulation Distortion Factor (SMPTE) 0.008%
Output Bandwidth (8 ohm load, 0.03% THD) 10 Hz to 50 kHz
Frequency Response (CD, Source Direct) 10 Hz to 100 kHz, + 0 -3dB
Damping factor 180 (8 Ω load, 20 Hz to 10 kHz)
Input Sensitivity / Input 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
S/N ratio (A-network) Phono MC:75dB
Phono MM:85dB
High Level:107dB
Power supply voltage AV100V, 50Hz/60Hz
Power consumption 220W (Electrical Appliance and Material Control Law)
External dimensions Width 454x Height 165x Depth 380 mm
Weight 17.5kg