Audio Database

The

Exclusive M3
315,000yen(around the 1975 time)

Description
 
Stereo power amplifier which challenged the threshold of the likelihood based on the true nature of an audio in order to make true quality articles, finished by handmade carefully from the assembly of component partses to the last coordination, and was completed at the high number of dimensions.

Using a differential amplification as two steps and a balanced amplification, the input circuit drove the driver stage with the pre driver of the Class-A push-pull circuit, and also has adopted the circuit system led to the power stage of the good triple push pull of a linearity also at the time of a large current.
All the circuitries have improved the property which adjusts a gain the optimal and to which NFB is not applied by local current feedback, and have stopped the quantity of NFB to necessary minimum.
Moreover, the Class-A PP circuitry of the pre-driver stage has balanced completely in direct current, it starts with low-distortion-ization, and the improvement in a property has an effect.

The peek power meter which can carry out the Direct reading of the musical peaking capacity level in the value of power is carried, and the tick mark can carry out a Direct reading without a sensitivity change by adopting a logarithmic comression circuitry to 0.01W-200W (-40dB - +3dB).
The start adopts the 磁 type meter outside large-sized with a quick and sufficient dumping as meter, and a pointer sways in a legible location also at the time of a small sound volume.

The glass epoxy group board with high intensity and robustness is adopted as the printed circuit board.
Moreover, high-precision and reliable component partses are selected carefully and used for the volume for level controls of a speaker until it results a sealing type communicated type in each of the resistors from a transistor further.
A power-source part has little leakage magnetic flux, and the large-sized cut-core power transformer excellent in the regulation and the power source capacitor of 33,000 micro Fx2 are adopted.

Three speaker terminations are carried and each system carries the level control.

The protection network has adopted the scheme which divided the functionality into two.
One protects a speaker, when direct current voltage occurs in an output, and it serves also as the power-source muting. Another prevents a corruption of amplifier from the overcurrent by a load-intensity short-circuit etc., and the method of detecting a trouble and restricting an input is taken.
Both detected the operation quickly in the detection circuitry, and circuit component part and a speaker system are protected certainly.

In order to prevent the surge current at the time of a power-switch injection, the current limiting was performed using the relay at the time of a switchpoint injection, and the surge current preventing circuitry which will be in normal operating state in several seconds is adopted.

By the circuit changing switch of the front panel, a selection of 1V and 2V is possible for Input sensitivity according to a preamplifier output.
Moreover, the Subsonic Filter builds in CR type and on/off of it is possible if needed.

The actual measurement measured for every set is attached as it is.

Rear Internal
Meter

Rating of a mode
Form Stereo power amplifier
Circuit system 2 steps of differentials PP drive
Three-step Darlington triple PP
Pure complimentary OCL scheme
Effective output 150W+150W (8 ohm, 20Hz - 20kHz, B.C.D)
THD 0.1% or less (at the time of an Output power)
Output bandwidth 5Hz - 35kHz
Frequency characteristic 10Hz-80kHz+0 -1 dB
Dumping factor 35 (8ohm) or more
Input sensitivity Input1, 2:1V, 2V
Subsonic Filter 8Hz, 6dB / oct
Speaker level control A, B, and C are :0--20dB.
Peek meter indicating range 0.01W-200W (-40dB - +3dB)
The semiconductor used Transistor: 84 pieces
IC: Six pieces
Diode: 82 pieces
Dimensions Width 468x height 206x depth of 370mm
Weight 27kg