Audio Database

B-2103  The pictorial image of MOS VINTAGE

360,000yen(1992 release)

A MOS FET element is adopted, and it is designed harness the capacity, and is stereo power amplifier.

The alpha-X balance circuitry which performs the balance operation which was consistent from the input of the source to the drive of a speaker is carried.
An output stage is made into the push pull scheme of Power MOS FET, and it is a speaker on either side + - It is driving on the same requirements with a total of four amplifier with which both were equipped.
the inphase distortion of a reverse electromotive style or an exogenous noise which realized the perfect separation of the amplifying circuit of amplifier, and a grounding circuitry by this, and the circuitry itself generated with the speaker -- a principle -- it has shut out to the law.
Furthermore, the original balance feedback stream composition which crosses from the - side output to the + side input is adopted as NFB from the + side output to the - side input, and wide-range-ization is attained.

As an output element of a power stage, Power MOS FET and the pair of 2SK405/2SJ115 are used.
Since the store-recording effect does not occur, this element is excellent in a linearity and enables the stable high-speed amplification.
Moreover, the silence in minute level is also high and the Advanced alpha-X balance circuitry and power-source part which were made into the low distortion and the low-impedance are drawing out the original tone quality of MOS FET.

In order to correspond to dynamic ranges, such as the digital source, the input was made into the cascade connection of FET and the NEW diamond differential circuit which can take out the output by the side of - without phase inversion on a power stage is adopted.
In accordance with a driver power source, the outstanding linearity, and large-current supply capacity and a high-speed responsibility are demonstrated, and the loss of the sound by occurrence of TIM distortion is suppressed.

In order to operate the MOS FET amplifier which needs the stable large current to the maximum extent, the power-source part of all the stage independent power feedings is carried.
The vibration suppression structure and the transformer of low leakage which carried out the original development were begun to the B-2103 special purpose, and the electric current which pursued low-impedance-izing and high speed-ization and was stabilized with highly efficient electrolytic capacitor and first recovery diode etc. is acquired.
Moreover, each stage was made into the independent source, and the final power source adopted the balance stream composition of the closed loop system made to separate from a grounding circuitry, and has prevented the tone-quality failure by the natural oscillation and noise of the unbalance of a power source, or a power-source part.

In order to eliminate the influence of an oscillation of the power-source part acting as the out-of-order of stereophonic reproduction, or a signal system, the twin monophonic construction which places a power-source part in the center of amplifier, and arranges a power unit symmetrically is adopted.
The image orientation and the phase response are improved by controlling an occurrence and propagation of an oscillation of a power transformer and a capacitor by the optimal weight balance of the structure, and also realizing shortest-ization of a circuitry by it.

In order to control a natural oscillation and a visitor oscillation of amplifier further, the isorated mechanical feedback is introduced.
For example, it is crowded with a pure-copper board on both sides of MOS FET, and pure-copper material is used also for each part, such as a transformer, a sole plate, an insulator.
Moreover, between the sole plate and the insulator, an isolated rate is carried out with a Teflon sheet, a propagation of an oscillation is intercepted, and the purity of the music signal is protected.

A gilding treatment, non-magnetic-material-izing, low-impedance-izing, high-speed-izing, the measure against vibration proof, etc. are put into practice among the part used as the point which determines a tone quality.
The impedance has adopted as a connector part the RCA gilding connector made from WBT which was low excellent also in the corrosion resistant, and the Neutrik gilding balance input terminal.
Moreover, parts, such as a gilding resistor (RMG) metallurgy plating film capacitor (GUG), an OFC lead capacitor, and the SILMIC electrolytic capacitor, are adopted.

In consideration of vibration proof, it is used for it, carrying out hand tooling of the aluminum board of 6mm thickness to the front panel which is a face of amplifier.
Furthermore, it has a stable structure by the side panel which carried out the interior of the 8mm thickness felt which absorbs unnecessary reflective sound, and the chassis which also made the top plate the product made from aluminum.
Moreover, the sole plate was made into the product made from a pure copper, and the W bottom of a copper plating chassis, and it has equipped with the large-sized insulator of the newly developed Naked made from an ellipse pure copper that uses a Teflon sheet and felt.
While using the internal loss which a pure copper has, the variance of the resonance was considered as the oscillation and the internal interference and the extraneous vibration are eliminated thoroughly.

Black Internal
A An
MOS FET Various

Rating of a mode
Form Stereo power amplifier
Effective output (10Hz - 20kHz, both channel simultaneous operation) 150W+150W (6ohms)
110W+110W (8ohms)
THD (at the time of an effective output) 0.008% (8ohms)
Cross modulation distortion 0.008% (8ohms)
Dumping factor 200 (8ohms)
Frequency characteristic (1W) DC-300kHz and +0 -3dB
Input sensitivity/input impedance (1kHz) 1V/10kohm
SN ratio (A network) 110dB or more
Dynamic power 190W (6ohms)
240W (4ohms)
320W (2ohms)
エンベ lobe distortion Below a limit of measurement
TIM distortion (SWATOOTH) Below a limit of measurement
Slew rate 150v/microsec
Rise time 0.5microsec
Channel separation (1kHz) 90dB or more
Subsonic Filter 10Hz (-3dB), 6dB / oct
Load impedance 4ohm-16ohm
Power source AC100V, 50Hz/60Hz
Power dissipation 350W
Dimensions Width 450x height 173x depth of 477mm
Weight 35.0kg