VICTOR/JVC AX-Z911
¥ 89,800 (around 1988)
Commentary
Pre-main amplifier equipped with digital pure A circuit.
In addition to the built-in D/A converter, we focus on the pure A-class operation of the amplifier and realize the pure A-class operation in order to review the fundamental quality so that it can be applied to digital sources.
Pure A-class operation does not perform signal synthesis like B-class operation, so switching distortion and crossover distortion do not occur in principle. However, pure A-class operation requires a huge power supply because the output current required for full-power operation is always kept constant. Moreover, heat generation is high and efficiency is low.
In order to solve these problems, the AX-Z911 is equipped with a digital pure A signal prediction circuit that quickly judges the magnitude of the input digital signal and supplies the corresponding power supply voltage to the amplifier only when necessary. This enables high-efficiency pure A-class operation without wasting power.
The D/A converter section uses a digital filter with 4 x oversampling.
In order to cut off the audio section from the digital section and power supply section, which are sources of noise, the digital signal processing section is shielded by a plate, and the board is separated from the analog signal processing section by a large heat sink.
In addition, the top plate of 3.2 mm thickness and the bottom plate of 1.6 mm thickness are adopted, and adverse effects caused by interference from structure and material are suppressed.
The transmission lines in the circuit are completely short and the contact points are reduced. Relay and electronic switch are used to suppress the routing of the input signal, and only one speaker terminal is used.
In addition, if the DAC direct switch is turned on until the digital signal is just before the D/A converter, the wiring length becomes only 0.5m and the number of contacts becomes only one. We are trying to simplify the circuit as much as possible.
When an analog source is played back, the digital clock operation is automatically stopped to suppress the influence of digital noise.
Uses a 2-point support volume with an excellent S / N ratio.
Built-in MC head amplifier.
A remote control is included.
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Model Rating
| Type | Digital basic amplifier |
| Overall characteristics (CD, Line1, 2, DAT1/Tape1, Tape2/DAT2) | |
| Rated output | 120W + 120W (6 ω, 1 khz, 0.0007% distortion) 110W + 110W (6 ω, 20 Hz to 20 kHz, 0.0035% distortion) |
| Total harmonic distortion factor | 0.0035% (8 Ω, 20 Hz to 20 kHz, at Rated Output) |
| Output bandwidth | 7 Hz ~ 60 kHz (8 Ω, both channel operation, 0.02% distortion rate) |
| Frequency characteristic | DC ~ 200 khz + 0 -3dB |
| Damping factor | 200 (1 kHz, 8 Ω) |
| Input Sensitivity / Impedance (1 kHz) | 400mV/30k Ω |
| Signal-to-noise ratio | 86dB(EIAJ) 112 dB (IHF short circuit) |
| Bus control (superbus) | 0 to + 5 dB (50 Hz, Volume -30dB) |
| PhonoRIAA deviation | MM, MC : 20 Hz to 20 kHz ± 0.2 dB |
| D/A Converter Unit | |
| Corresponding sampling frequency | 32 kHz, 44.1 kHz, 48 kHz (automatic switching) |
| Total harmonic distortion factor | 0.0035% (1 kHz, EIAJ) |
| Signal-to-noise ratio | 102dB(EIAJ) |
| Dynamic range | 97dB(EIAJ) |
| Input | Digital1 (optical) : -23 to -14dBm Digital2, DAT Play (coaxial) : 0.5Vp-p/75 Ω |
| Output | DATRec (Coaxial) : 0.5Vp-p/75 Ω |
| <General> | |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power outlet | Power switch not linked : 2 systems (maximum 200W) |
| Power consumption (Electrical Appliance and Material Control Law) | 200W |
| External dimensions | Width 435x Height 166x Depth 442 mm |
| Weight | 19.0kg |
| Attachment | Remote Controller RM-SA911 |