Audio Database

The

NEC A-7
79,800yen(around the 1983 time)

Description
 
The reserve IBM-PCN-II power-source loading Integrated Amplifier which inherited the circuitry technology of A-11 and was developed.
The simple stream composition is adopted and accessories carry only the required functionality.

The parallel push-pull circuit is carried in the last power stage.

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.

In order to correspond to MC cartridge, high gain equalizer amplifier is carried.
It is circuitry which uses low-noise high gain FET, and the correspondence is aimed at also to man-month cartridge with the gain changeover switch whose proper use is possible by two positions.


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
100W+100W (4ohm)
50W+50W (8ohm)
THD (at the time of an effective output) 0.006% or less
Cross modulation distortion (at the time of an effective output) 0.006% or less
Frequency characteristic 5Hz - 300kHz
<Preamplifier part>
Circuit system High Gm FET direct input EQ circuitry
Input sensitivity/impedance Phono man month: 2.5mV / 47kohm
Phono MC: 250 microvolts/100 ohm
compact disk, Tuner, AUX, Tape1, 2:150mV / 47kohm
An Output voltage/impedance Rec output: 140mV / 2.2kohm
SN ratio Phono MM:90dB(-142dBV)
Phono MC: 73dB/250 microvolts (-145dBV)
compact disk, Tuner, AUX, Tape1, 2:110dB (-126dBV)
RIAA deflection Less than [ 10Hz-100kHz±0.2dB ]
Phono maximum permissible input MM:150mV
Muting -20dB
Subsonic Filter 15Hz (-3dB, 6dB / oct, phone equalizer partitioned)
Input/output phase Inphase
<Synthesis>
Power circuit scheme Shunt power-source scheme + reserve power source
Power consumption 190W
Dimensions Width 430x height 150x depth of 380mm
Weight 13kg