Audio Database
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The pure Class A stereo power amplifier which aimed at the high-quality music reproduction with a small output by introducing the high-grade technology and the element of the highest grade which examined each part thoroughly.

The output amplification stage has a configuration in which power MOS FETs are connected in 3-parallel.
This is attached to a large heat sink to support low load impedance.
The parallel connection can reduce the intrinsic capacitance of the element, output impedance, internal noise, and dissipate the heat generated by the element.
Also, since it is a pure Class A operation, a large current is always flowing, but it is a MOS due to the parallel connection. The power saving area with excellent linearity of the FET can be used comfortably, which greatly contributes to the improvement of performance and sound quality.
The maximum clipping level is set to 50W (8Ω) to save the occasional, momentary, pulsed music signal from clipping.

The current feedback type amplification circuit which returns an output signal in the form of current is adopted.
This circuit first lowers the impedance of the input terminal on the feedback side, detects the current, and I-V converts the current with a transformer impedance amplifier to create an output signal. Since the impedance of the feedback input section is extremely low, phase rotation is difficult to occur, and as a result, there is no need for phase guarantee.
Therefore, it has excellent dynamic characteristics such as rising, and the sound quality is greatly improved by natural energy response.
In this circuit, there is almost no change in frequency characteristics due to the magnitude of gain.

There is no phase disturbance due to NFB, and the current feedback amplifier circuit boasts excellent stability, allowing gain control of the NF amount switching system.
In this method, when the gain of the amplification section is lowered, the noise component also drops at the same time, so it is very effective in reducing the residual noise in the high-frequency range of high-efficiency speakers and multi-amplifier systems.

Bridge connection is possible by the changeover switch.
Bridge connection is a method of inputting signals of opposite phase to each other with the same voltage to a 2-channel amplifier, and connecting speakers to the output terminals of both amplifiers. By this method, you can upgrade to a monaural amplifier.

Supports balanced connection that is less susceptible to external induction noise.

High-purity copper has been used for parts that pass signals.
Furthermore, a plate is formed on this with gold to reduce the skin resistance and smooth the flow of current.
In addition to the copper foil surface of the printed boat, the input terminal and speaker terminal are thoroughly improved to improve the sound quality.

The power supply uses a high-efficiency transformer with a large power capacity of about 400VA, which is fixed with a highly vibration-proof filling material and enclosed in a case.
Moreover, the 47,000-micro Fx2 large-capacity and high-quality sound type is used for the smoothing capacitor, and it has a structure strong against vibration by applying an elastic soft coating.

The analog type is adopted as the power meter, the peak value of the signal is captured, and the power value of a wide range can be directly read by logarithmic compression.
In addition, it is equipped with a gain switch that makes it easier to read even with a small output and a switch that turns off the meter operation and lighting.

Equipped with a large speaker terminal that supports banana plugs that can support thick speaker cables.
For the material, solid brass is carved out into a gold plate, and a mold cap for insulation is put on it.

Model rating
Type Stereo power amplifier
Rated continuous average output (between 20Hz and 20kHz) Stereo specification (simultaneous operation on both channels)
2Ω: 80W/ch
4Ω: 40W/ch
8Ω: 20W/ch
Monaural specification (bridge connection)
4Ω: 160W
8Ω: 80W
Total harmonic distortion rate Stereo specification (simultaneous operation on both channels)
2Ω: 0.05%
4-16Ω: 0.02%
Monaural specification (bridge connection)
4-16Ω: 0.02%
IM distortion rate 0.003%
Frequency characteristics 20Hz to 20,000Hz, +0 -0.2dB (at rated continuous output)
0.5Hz ~ 160,000Hz, +0 -3.0dB (at 1W output)
Gain (gain) 28.0dB (at GAIN switch MAX)
(Both stereo/monaural)
Load impedance Stereo specification: 2-16Ω
Monaural specification: 4 to 16 Ω
Damping factor Stereo specification: 120
Monaural specification: 60
Input sensitivity (8Ω load) Stereo specification
0.50V (at rated continuous average output)
0.11V (at 1W output)
When monaural specifications
1.00V (at rated continuous average output)
0.11V (at 1W output)
Input impedance Balance: 40kΩ
Unbalance: 20kΩ
S/N (A correction) 110dB (input short-circuit, rated continuous average output)
Power meter level Logarithmic compression type
NORMAL :-40dB to +5dB and output value direct reading scale
-20dB :-60dB to -15dB and output value direct reading scale
power supply AC100V, 50Hz/60Hz
Power consumption No input: 160W
Electrical Appliance and Material Control Law: 250W
8Ω rated output: 180W
Outer dimensions Width 475x height 170x depth of 427mm
weight 21.6kg