Audio Database

The

NEC A-11
149,000yen(around the 1983 time)

Description
 
The Integrated Amplifier of reserve IBM-PCN-II power-source loading which made no compromise, but considered the basics of amplifier and was developed by the extravagant circuit design.

While a circuitry structure adopts a push pull form amplifying circuit as all the amplification stages, the last amplification stage is considered as the parallel push pull stream composition. Furthermore, the whole page independent shunt-regulator type power circuit is adopted.

The stage independent 4 power-source part and the reserve IBM-PCN-II power source are adopted as a power-source part.
This developed the reserve power source further, delays the phase of a power-source output 90 degrees, and is filling the valley of the ripple. The fall of supply voltage which takes place by this when it is going to acquire the Oide power with a capacitor input type power source at the time of a capacitor electric discharge is prevented.
This has improved a power-source ripple of about 10dB, and the low-pass play distorted also at the time of the Oide power which is not is enabled.

The operation switchpoint which can use a pre part and a power part independently is carried.
If a switchpoint is made into "SEPARATED", the input of a power amplifier part and the output of a preamplifier part are separated, and it can be used independently, respectively.
Moreover, the input level of the power amplifier part serves as a right-and-left independent variable type.

The accessories circuitry is omitted as much as possible, and does not carry a tone control circuit, either.

Internal

Rating of a mode
Form High-quality integrated amplifier
<Power amplifier part>
Circuit system Whole page direct DC servo circuitry
Effective output (both channel drive)
A sinusoidal consecutive output, 20Hz - 20kHz
140W+140W (4ohm)
70W+70W (8ohm)
THD (at the time of an effective output) 0.003% or less
Cross modulation distortion (at the time of an effective output) 0.003% or less
Frequency characteristic 5Hz - 300kHz
<Preamplifier part>
Circuit system Whole page direct DC servo circuitry
Input sensitivity/impedance Phono man month: 2.5mV / 47kohm
compact disk, Tuner, AUX, Tape1, 2:150mV / 10kohm
An Output voltage/impedance Rec output: 150mV/100 ohms
Preamplifier output: 1.23V/600 ohm
SN ratio Phono MM:90dB(-142dBV)
compact disk, Tuner, AUX, Tape1, 2:110dB (-126dBV)
RIAA deflection It is 10Hz - 100 kHz . less than ±0.2dB.
Phono maximum permissible input 300mV
Input/output phase Inphase
<Synthesis>
Power circuit scheme Stage independent shunt-regulator scheme + reserve power source
Power consumption 250W
Dimensions Width 430x height 150x depth of 430mm
Weight 24kg