Pioneer A-470
¥ 49,800 (released in 1980)
Commentary
This pre-main amplifier has a simple circuit structure and is designed with consideration not only for appearance but also for usability.
It is equipped with a REC selector that can air check FM broadcasting while listening to the record.
The power section uses a DC amplifier configuration without the condenser, which causes the coloring of sound.
This suppresses the deterioration of the damping caused by the capacitor, the phase shift in the middle and low frequencies, and the transient intermodulation distortion.
Super Linear RET (Ring Emitter Transistor) is used for the transistor of the power section.
By adopting a group transistor with superior linearity in the high-frequency range, the high-frequency characteristics have been improved.
The equalizer section uses an ICL type FET differential input circuit.
In addition, it is equipped with the MC position to which the MC cartridge can be directly connected, so you can enjoy the MC cartridge by just switching the switch.
It is equipped with a subsonic filter that cuts out unwanted ultra-low frequencies (below 15 Hz) and a loudness contour that is useful for low-volume playback.
Model Rating
| Type | Pre-main amplifier |
| Effective power | 50W+50W (8 Ω, Distortion Factor 0.01%, 20 Hz to 20 kHz, Double-channel Drive) |
| Harmonic distortion factor | 0.006% (8 Ω at 25W output) |
| Intermodulation distortion factor (50 hz : 7 khz = 4 : 1) | 0.006% (8 Ω at 25W output) |
| Output bandwidth | 5 Hz ~ 30 kHz (IHF, both channel drive, THD0.01%) |
| Phono maximum allowable input (1 kHz, 0.01% THD) |
MM:200mV MC:20mV |
| Frequency characteristic | Phono MM : 20 Hz to 20 kHz ± 0.5 dB |
| Signal-to-noise ratio (IHF, A-network Short circuit) |
Phono MM:87dB Phono MC:70dB |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption (Electrical Appliance and Material Control Law) | 120W |
| External dimensions | Width 420x Height 120x Depth 368 mm |
| Weight | 8.5kg |