NEC A-7
¥ 79,800 (around 1983)
Commentary
A pre-main amplifier with a Reserve II power supply developed by inheriting the circuit technology of A-11.
It has a simple configuration with accessories that only have the features you need.
A parallel push-pull circuit is mounted on the final power stage.
Stage independent 4 power supply and reserve II power supply are used for the power supply.
This is a further development of the reserve power supply. The phase of the power supply output is delayed by 90 degrees to fill the valley of the ripple. This prevents the voltage drop that occurs when a capacitor input power supply attempts to obtain a large output when the capacitor is discharged.
A high-gain equalizer amplifier is installed to support MC cartridges.
It has a circuit configuration using a low-noise high-gain FET, and is compatible with MM cartridges by a gain switching switch that can be used in two positions.
Model Rating
Type | High-quality integrated amplifier |
Power Amplifier Unit | |
Circuit system | All-stage direct DC servo circuit |
Effective output (both channel drive Sine wave continuous output, 20 Hz to 20 kHz) |
100W + 100W (4 Ω) 50W + 50W (8 Ω) |
Total harmonic distortion factor (at effective output) | Not more than 0.006% |
Cross modulation distortion factor (at effective output) | Not more than 0.006% |
Frequency characteristic | 5 Hz to 300 kHz |
Preamplifier Section | |
Circuit system | High Gm FET direct input EQ circuit |
Input Sensitivity / Impedance | Phono MM : 2.5mV/47k Ω Phono MC : 250 μ V/100 Ω CD, Tuner, AUX, Tape1, 2 : 150mV/47k Ω |
Output Level / Impedance | Rec Output : 140mV/2.2k Ω |
Signal-to-noise ratio | Phono MM:90dB(-142dBV) Phono MC : 73dB/250 μ V (-145dBV) CD, Tuner, AUX, Tape1, 2 : 110 dB (-126dBV) |
RIAA deviation | 10 Hz to 100 kHz ± 0.2 dB or less |
Phono maximum allowable input | MM:150mV |
Muting | -20dB |
Subsonic filter | 15 Hz (-3dB, 6dB/oct, built-in phono equalizer) |
Input-output phase | Inphase |
<General> | |
Power supply circuit system | Shunt power supply system + reserve power supply |
Power consumption | 190W |
External dimensions | Width 430x Height 150x Depth 380 mm |
Weight | 13kg |