Technics SU-8600
¥ 79,800 (released in 1975)
Commentary
A pre-main amplifier that further pursued the dynamic distortion introduced in SU-10000 and SE-10000.
In order to improve the stability of the power supply part and suppress transient distortion, the ± 6 power supply system is adopted and the accuracy of parts is improved.
The output stage of the tone control circuit and the pre-drive stage of the main section use a constant current load that combines a transistor and a diode. This ensures constant current even when voltage changes, and provides stable performance with little gain change or distortion.
A constant voltage power supply of ± 6 power supplies enables highly stable operation even at the time of Tsutomu Dainyu.
The equalizer circuit consists of two stages directly connected, differential amplifier and modified SRPP output stage.
The selective use of low-noise transistors also improves the SN ratio.
The main amplifier consists of differential amplification, emitter-follower, voltage amplification, and output stage.
The dynamic characteristics are improved by adopting a stabilized power supply of ± 4 power supply, using a high-permeability core and a power transformer with good regulation by increasing the diameter of the winding, and using 15000 μ f electrolytic capacitor.
The tone control section is a 3-stage directly connected tone control circuit with differential amplification with current mirror load at the first stage and appropriate gain distribution.
The turnover frequencies can be switched between two levels for low and high tones, and a tone defeat switch is also installed.
The volume uses a newly developed 26-contact type attenuator that can set the frequently used level from -30dB to -40dB in 2 db steps.
Equipped with a Detent + Loudness terminal, the loudness automatically works at low volume to compensate for the lack of bass.
It is equipped with functions such as low-high filter, loudness switch, tape monitor circuit and muting switch.
There was a wood case sold separately.
Model Rating
Type | Stereo pre-main amplifier |
Power Amplifier Unit | |
Effective output (both channels) | 1 kHz : 76W + 76W (8 Ω) 20 Hz to 20 kHz : 73W + 73W (8 Ω) |
Total harmonic distortion factor | 0.08% |
Output Bandwidth (both channels, 8 Ω) | 5 hz to 70 khz -3dB |
Frequency characteristic | 5 hz ~ 100 khz + 0 -3dB |
Signal-to-noise ratio (IHF-A) | 115dB |
Residual noise | 0.3mV |
Damping factor | 50 (8 Ω) |
Input Sensitivity / Impedance | 1V/47k Ω |
Load impedance | Main, Remote : 4 Ω ~ 16 Ω Main + Remote : 8 Ω ~ 16 Ω |
Preamplifier Section | |
Input Sensitivity / Impedance | Phono1, 2 : 2mV/47k Ω Tuner, AUX, Tape Deck1, 2, Playback : 150mV/47k Ω |
Phono Maximum Input (1 kHz, RMS) | 200mV |
Total harmonic distortion factor | 0.08% |
Signal-to-noise ratio (IHF-A) | Phono:73dB Tuner, AUX : 92 dB |
Frequency characteristic | Phono1 and 2 : RIAA standard curve ± 0.4 dB Tuner, AUX : 5 hz to 80 khz + 0 to 3 db |
Tone control | Bass : 50 Hz, ± 12 dB Treble : 20 kHz, ± 12 dB |
Turnover frequencies | With Defeat Switch Bass : 250 Hz, 500 Hz Treble : 2.5 kHz, 5 kHz |
Filter | Low : 30 Hz, -6dB/oct. High : 8 kHz, -6dB/oct. |
Loudness control | 100 Hz, + 8 dB (Volume -30dB) |
Output voltage | Pre Out : 1 v (rated), 8 v (maximum) Tape Deck1, 2, Rec Out : 150 mv |
<General> | |
Power supply voltage | 100 VAC, 50/60Hz |
Power consumption | 180W |
External dimensions | Width 450x Height 173x Depth 345 mm |
Weight | 12.7kg |
Attachment | 1 x circuit protection fuse (5A) |
Sold Separately | Wood Case SH-780 (¥ 4,000) |