Audio Database


Accuphase M-1000
650,000 yen(one set, the November, 1987 release)


It is the monophonic power amplifier developed towards an audio new time as first full-scale Oide power power amplifier as a noncommercial use.
Not only a merely big output but the height of the quality of sound is thought as important, the comb of the development technology of an Accuphase is carried out, and the maximum engine performance is pursued.

It consists of balance systems which made two-set bridge connection of the whole page push pull drive unit amplifier, and the engine performance is raised.
by having adopted the balance system with the transmission system only for a plus signal and a minus signal, distortion generated with amplifier is also canceled in an output circuit, and takes out a pure signal ingredient at the same time external noise is canceled theoretically -- it has come to be able to carry out things

Each unit amplifier has adopted gorgeous composition called a 14-parallel push pull, and, as for the output transistor, specification of a total of 56 pieces is carried out in the collector loss 150W and two units.
Moreover, the large-sized radiator of the aluminum Naked is attached and it is possible to use it without a heat dissipation fan in the usual state.

It arranges so that every load impedance can take out large electric power, and an output stage may be changed to the operating state which matched each condition.
By changing low load impedance for the switch which changes impressed electromotive force, the large current of 1100W can be taken out by 1600W or 2-ohm load with 1-ohm load.

In order to improve the quality of the input magnification circuit of a signal, the Class-A cascode differential push pull system is adopted as the input stage of all the power amplifier.
Since a cascode circuit is a circuit used for high frequency magnification, over a large frequency band, operation is stable, and the linearity of an input also has it, and it has secured the large dynamic range. [ good ]

To the switching distortion at the time of the Koide power produced in an output stage, the operating point is strictly set up so that the element of PNP and each NPN may not be cut off with an incoming signal.
And the preceding paragraph which drives a final stage has adopted MOS FET equivalent to a non switching Class-A drive, and, moreover, constitutes it from a cascode push pull. The preceding paragraph which transfers a signal to this MOS FET is also made into the Class-A cascode push pull.
This constitutes few stable output stages distorted from the Koide power of a noise domain to the Oide power of an Output power.

The power-source part has 2 power-source composition by an independent transformer. These are connected in parallel and the power-source part of a total of 3 kVA is constituted.
The power-source impedance seen from the amplifier side becomes half by this, and maximum dissipation capacity has become twice.
Moreover, a filter condenser also becomes equivalent to the power source of 66000micro-Fx2.

The output meter has equipped peak display type analog meter and the digital meter which displays the true value of electric power.
An analog form displays an electric power dB scale and equivalent electric power with a peak value.
Digital meter detected the voltage and the true value of current which are supplied to the speaker, found electric power by the analog multiplication part, and has adopted the system of displaying a true value.
A display digit number is 4 figures and a range change has five positions of a maximum of 2W, and 200W, 2000W and 10000W. Moreover, hold time serves as four infinite positions for 0.5 second, 3 seconds, and 75 minutes.

The input is equipped with the terminal of a balance input and an imbalanced input, and these input systems can be chosen with the switch inside a front sub panel.

Although there is no necessity for a heat dissipation fan in the state of anticipated use, the fan in the case where it sets to the bad place of the heat dissipation effect, and the case of performing the Oide power drive over a long time is an option.
The fan is considered so that it may be attached inside the sideboard of both sides.

The board of natural persimmon finishing is adopted as both sides.


Rating of a mode
Form Monophonic power amplifier
Continuation average output
(For 20Hz - 20kHz)
Normal Load Imp.Operation (0.01% of distortion) 4ohm: 1800W
8ohm: 1000W
16ohm: 500W
Low Load Imp.Operation (0.05% of distortion) 1ohm: 1600W
2ohm: 1100W
4ohm: 550W
THD 1-4ohm load: 0.05%
4-16ohm load: 0.01%
IM distortion 0.003%
Frequency response 20Hz - 20kHz, ±0dB (at the time of a continuation average output level control MAX)
0.5Hz - 150kHz, and +0 -3.0 dB (at the time of 1W output level control MAX)
0.5Hz - 80kHz, and +0 -3.0 dB (at the time of 1W output level-control 6dB)
Gain 28.0dB
Load impedance Normal Load Imp.Opaeration: 4-16ohms
Low Load Imp.Operation: 1-4ohms
Dumping factor 200(EIA 50Hz)
Input sensitivity
Normal Load Imp. Operation 3.56V (at the time of 8-ohm load and a continuation average output)
0.12V (at the time of 8-ohm load and 1W output)
Low Load Imp. Operation: 1.87V (at the time of 2-ohm load and a continuation average output)
0.06V (at the time of 2-ohm load and 1W output)
Input impedance Unbalance: 20kohm
Balance: 40kohm
S/N (A-compensation) 125dB (at the time of input short-circuit and a continuation average output)
95dB (at the time of input 1kohm and 1W output)
Analog type power output meter Logarithm compression peak display type
- 60dB - +3dB, and an output Direct-reading scale
Digital type power output meter
Form The true value display type of electric power
Display range It is a Direct reading about 0.001W-9,990W by range change.
Effective digit number 3.5 figures
Range 2:0. 001-1.999W
20:0. 01-19.99W
200:0. 1-199.9W
2000: 1-1,999W
10000: 10-9,990W
Accuracy Less than 2kW : 3% ±5 count
2kW or more : 3% ±50 count
Hold time 0.5 sticks, 3 seconds, 75 minutes, infinity
The semiconductor used 99Tr, 13FET, 31IC, 142Di
Power source 100V, 117V, 220V, 240V, 50Hz/60Hz
Power consumption At the time of no inputting: 120W+120W
Electrical Appliance and Material Control Law: 600W+600W
At the time of an 8ohm load Output power: 800W+800W
Dimensions the width 481x height 239(piece -- it includeds) x depth of 489mm
Weight 47.2kg
Option Fan for heat dissipation O-83 (10,000yen)