Audio Database


Accuphase M-2000
1,000,000 yen(one set, the December, 1997 release)


Monophonic power amplifier developed aiming at the constant-voltage drive of an ideal.

The high power transistor of the collector loss 130W and collector current 15A is adopted. This was constituted from a 22-parallel push pull, and super-low impedance-ization is measured. And these elements are attached on the huge heat sink by aluminum die-casting, and efficient heat dissipation processing is carried out.
The power excellent also in the load drive capability to have realized the Oide power power amplifier even with linear super-low impedance load, and for the reactance component to have been includeded is demonstrated as a result of this degree of margin.

The current feedback type magnification circuit which returns an output signal in the form of current is adopted.
First, the impedance of the input terminal by the side of a return is lowered, and current is detected. I-V (current-voltage) conversion of the current is carried out with a transformer impedance amplifier, and an output signal is made.
Since the impedance of a return input portion is very low, it is hard to generate phase rotation and, as a result, most phase compensation is not needed.
Thereby, since many characteristics are sharply improvable by a little NFB, it excelled in dynamic characteristics, such as a standup, and the natural energy response has been obtained also in respect of sound quality.

By bridge connection which uses two sets of M-2000, an output can be reinforced 4 times.
Bridge connection inputs the signal of an inversion phase mutually on the same voltage, and connects a speaker to two sets of amplifier at the output end of both amplifier.
in the time of bridge connection, 4 times as many outputs can be obtained and it is 1000W/8 ohm -- super- -- a crossbow -- it becomes class monophonic amplifier.

The balance contact button which cannot receive visitor guidance noise easily is carried.

The parts which a signal passes are performing plate-ization with gold on this in M-2000, although copper with usually high purity is used.
Improvement in the thorough sound qualities, such as a grounded plate, a capacitor terminal, an input terminal, a speaker terminal, etc. in which a printed board Copper-foil side and big ripple current flow, is aimed at.

The hypermarket ring type toroidal transformer of the large power capacity of about 1.5 kVA is adopted as a power-source part.
This transformer is excellent in heat conduction, using the high load material of the vibrationproofing effect, adheres to the unresonated aluminum case of efficient heat dissipation structure, and is intercepting the influence on the exterior.
Furthermore, the section of the iron core was close to the circle, the coil could also be rolled closely circularly, and since adhesion nature is good, the loss has made weight light few. The leakage flux at the time of load is also small, and a roar and vibration are also small. Moreover, iron loss and in rushes current are made small by enlarging the rate of a bulk density of copper wire for the cross-sectional area of an iron core small.
Moreover, two large-sized things of 40,000 micro F / 120WV are adopted as an electrolytic condenser.

The phase switch which reverses the phase of the whole equipment is carried.
Since the method of changing only replaces plus and minus of the balance amplifier input unit, it does not have degradation of sound quality.

The logarithm compression type large-sized power meter is carried.
ON/OFF of meter operation and lighting is possible.

It can respond also to a very thick speaker cable -- the large-sized speaker terminal is overly carried.
It is begun to delete brass Naked material, and a material forms it into a golden plate, and has put the mould cap of the insulated purpose on it.

Golden Large-sized

Rating of a mode
Form Monophonic power amplifier
Rated continuation average output
(For 20Hz - 20kHz)
1ohm load: 2000W (it restricts to a music signal)
2ohm load: 1000W
4ohm load: 500W
8ohm load: 250W
THD 1ohm load: 0.1%
2ohm load: 0.05%
4ohms - 16ohm load: 0.03%
IM distortion 0.003%
Frequency response At the time of a rated continuation average output: 20Hz-20000Hz+0 -0.2 dB
At the time of 1W output: 0.5Hz-160000Hz+0 -3.0 dB
Gain (profit) 28.0dB
Load impedance At the time of a continuation output: 2ohms - 16ohms
At the time of a music signal: 1ohm - 16ohms
Dumping factor 400
Input sensitivity (8-ohm load) At the time of a rated continuation average output: 1.78V
At the time of 1W output: 0.11V
Input impedance Balance: 40kohm
Unbalance: 20kohm
S/N (A-compensation) 120dB (at the time of input short-circuit and a rated continuation average output)
Power output meter Logarithm compression type
- 60dB - +3dB, and an output Direct-reading scale
Power source AC100V, 50Hz/60Hz
Power consumption At the time of no inputting: 180W
Electrical Appliance and Material Control Law: 950W
At the time of an 8ohm Output power: 585W
Dimensions Width 475x height 252x depth of 545mm
Weight 50kg