SANSUI AU - α 307
¥ 45,000 (around 1989)
Commentary
This pre-main amplifier has obtained high dynamic power by strengthening the power supply section.
In the power supply system using a complimentary service circuit, variations in the center tap and unbalanced load current flow, adversely affecting sound quality.
In order to solve this problem, a ground stabilized circuit is adopted between the center tap and the ground to rationally eliminate spike noise, thereby improving the SN in the sense of hearing not only at high output but also at low output.
The power amplifier section employs a high-speed power transistor at the final stage of the power amplifier stage, and is composed of 3-stage Darlington complimentary service push-pull.
The driver stage is a discrete configuration with a first stage transistor for differential amplification and a second stage complimentary service push-pull circuit.
Equipped with an MC phono equalizer with High/Low switching, compatible with the output impedance of MC cartridges.
Equipped with REC selector with OFF position.
.JPG)
Model Rating
| Type | Integrated amplifier |
| Power Amplifier Unit | |
| Effective Output (10 Hz to 20 kHz, channel operation) | 75W + 75W (6 Ω) 65W + 65W (8 Ω) |
| Total harmonic distortion factor (at effective output) | 0.05% or Less (8 Ω) |
| Frequency Response (1W) | 1 Hz ~ 200 kHz + 0 -3dB |
| Signal-to-noise ratio (A network) | 105 dB or more |
| Preamplifier Section | |
| Input Sensitivity / Impedance (1 kHz) | Phono MM : 3.5mV/47k Ω Phono MC : 420 μ V (Low : 22 Ω, High : 100 Ω) CD, Tuner, Line, Tape Play : 200mV/47k Ω |
| Phono maximum allowable input | MM(THD 0.1%):130mV |
| Frequency characteristic | Phono MM : 20 Hz to 20 kHz ± 0.5 dB CD, Tuner, Line, Tape Play : 1 hz to 200 khz + 0 to 3 db |
| Signal-to-noise ratio (A network) | Phono MM : 80 dB or more Phono MC : 65 dB or more CD, Tuner, Line, Tape Play : 105 dB or higher |
| Tone control | Maximum variation of Bass : ± 8 dB (50 Hz) Maximum variation of Treble : ± 8 dB at 10 kHz |
| Subsonic filter | 16 Hz (-3dB), 6dB/oct. |
| Loudness | + 10 dB at 50 Hz, + 4 dB at 10 kHz |
| <General> | |
| Rated power consumption | 170W |
| External dimensions | Width 430x Height 136x Depth 311 mm |
| Weight | 9.0kg |