VICTOR/JVC A-X5
¥ 69,800 (around 1979)
Commentary
Pre-main amplifier that adopts super A circuit.
The A-X5 is designed to clean all signal circuits and has only two amplification stages : a high-gain MC / MM/DC servo equalizer and a high-gain super A/DC power amplifier.
There is only a power amplifier between Tuner, Tape, Aux and Spout, and there is no coupling capacitor at all. It is a complete DC of one amplifier configuration.
Super A circuit is used for the power amplifier section.
This circuit is composed of an A-class power stage with power efficiency and high linearity comparable to B-class amplifiers, and an extra low distortion factor driver stage to compensate for the non-linearity of semiconductors. This realizes both A-class sound quality and high power.
Newly developed DC servo equalizer is used in the equalizer amplifier section.
This circuit is a servo amplifier system that improves DC stability by cutting out the ultra-low band that is unnecessary for music playback, and realizes a high gain equalizer that was impossible in the past. This circuit is compatible with MC/MM cartridges without an MC head amplifier.
A direct power supply system has been adopted for the power supply section. The secondary side of the large transformer is separated into a voltage amplifier stage and a power amplifier stage, and is directly connected to each circuit to reduce power supply impedance over a wide band.
In addition, a large heat sink is used as a shield between the power supply and the drive circuit to prevent magnetic field lines from jumping due to large currents.
The output stage has the latest high f.TUses a power transistor.
In addition to the Super A driver stage with fast response speed, we have succeeded in suppressing TIM distortion, which has a large adverse effect on sound quality.
A newly developed tone control for the audio band that reduces unnecessary variations between the ultra-low band and ultra-high band is adopted.
LED function indicators are mounted on the front panel.
Equipped with an equalizer / subsonic filter to reduce ultra-low frequency noise when playing back records.
Equipped with a loudness function.
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Model Rating
| Type | Pre-main amplifier | ||
| Circuit system | Equalizer Amplifier : DC Servo Pair EL-FET Double Connected ICL Power Amplifier : Super A Full DC Dual FET Cascode-connected ICL High Gain Amplifier Power Supply Unit : 2 independent power supply all stages direct power supply system |
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| Effective output (Tuner, Aux, Tape → Spout) | 70W + 70W (8 ohm, 20 hz to 20 khz, THD0.007%) 73W + 73W (8 ω, 1 khz, THD0.0008%, By HP ・ IB Audio Analyze System) |
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| Total harmonic distortion factor (8 Ω at effective output) |
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| Cross modulation distortion factor | 0.004% (60 Hz : 7 kHz = 4 : 1, effective output, 8 Ω, Tuner/Aux/Tape → Spout) | ||
| Switching distortion | 0 | ||
| TIM Distortion | 0(LPF fc=100kHz) | ||
| Output bandwidth | 5 Hz ~ 70 kHz (IHF, both channel operation, 8 Ω, THD0.02%, Tuner/Aux/Tape → Spout) | ||
| Frequency characteristic | DC ~ 100 kHz + 0 -3dB (8 Ω, Tuner/Aux/Tape → Spout) | ||
| Damping factor | 75 (1 khz, 8 Ω, Tuner/Aux/Tape → Spout) | ||
| Input Sensitivity / Impedance (1kHz) |
Phono1/2 mm : 2.5mV/47k Ω Phono1/2 mc : 200 μ V/100 Ω Tuner, Aux, Tape1/2 : 200mV/47k Ω |
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| Signal-to-noise ratio |
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| Tone control | Bass : ± 8 dB (100 Hz) Treble : ± 8 dB (10 kHz) |
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| Subsonic filter | 18 Hz, -6dB/oct. (Equalizer Subsonic) | ||
| Loudness (Vol-30dB) | + 6 dB (100 Hz), + 4 dB (10 kHz) | ||
| Muting | -20dB | ||
| Equalizer amplifier section (Phono → Rec out) | |||
| Phono maximum allowable input (1 kHz, THD0.005%) |
MM:250mV MC:18mV |
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| RIAA deviation | 20 Hz to 20 kHz ± 0.2 dB | ||
| Total harmonic distortion factor (20 hz to 20 khz at 10 v output) |
MM:0.005% MC:0.02% |
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| Rec Output Voltage / Impedance | 200mV/1k Ω | ||
| <Others> | |||
| Power outlet | Switched : two systems Unswitched-One system |
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| Pwer | 100 VAC, 50Hz/60Hz | ||
| Power consumption | 160W (Electrical Appliance and Material Control Law Standard) | ||
| External dimensions | Width 450x Height 139x Depth 422 mm | ||
| Weight | 11.5kg | ||