Audio Database

Image of SA-6600II
Commentary

This is a pre-main amplifier that emphasizes sound quality and has an improved circuit to draw out the necessary power while minimizing distortion.

The NFB circuit of the equalizer section uses carefully selected elements such as a resistor with an error of less than 1% and a capacitor with an error of less than 2%. In addition, a dynamic margin of a maximum allowable input of 200 mV is obtained by using a high voltage IC and ± 2 power supply (+ 21V/-19V).

The flat amplifier uses a two PNP-NPN configuration with low noise and low distortion factor, and uses a circuit that increases the power supply utilization factor and expands the dynamic range.
The next stage tone control circuit uses a CR type, an 11-point an 11-point click-stop type is used for the knob, and a tone on-off switch is installed to make the tone flat only by operating the lever switch.

The first stage PNP differential and all stages direct connect pure complimentary service OCL system are adopted for the circuit configuration of the power amplifier section.
The pre-driver stage is a constant-current load that reduces the low-frequency time constant, enabling extended playback to the ultra-low frequency range. In addition, the pre-driver stage reduces the load on the pre-driver, allows a large gain in the linear region of the transistor, and achieves excellent characteristics by stably applying NFB to the ultra-low frequency range.

The power supply uses a large transformer and a 6,800 μ Fx2 capacitor.

The protection circuit is composed of an electronic circuit using TRIAC and a fuse.
In addition, in order to reduce the clicking sound when the power is turned on and off, a power muting circuit with three transistors is installed.

Equipped with a loudness contour and a 2-system tape monitor.

Model Rating
Type Stereo pre-main amplifier
Circuit system Power Amplifier : Pure complimentary service OCL
Equalizer : High voltage IC with two positive and negative power supplies
Tone control part : Positive / negative 2 power supply 2-stage direct connection flat amplifier, CR type tone
Effective power
(Both channel drive, 20 Hz to 20 kHz)
27W + 27W (4 Ω)
25W + 25W (8 Ω)
Harmonic distortion factor (20 Hz to 20 kHz) 0.1% (Effective Output)
0.05% (8 Ω at 13W output)
0.05% (8 Ω at 1W output)
Intermodulation distortion factor (50 hz : 7 khz = 4 : 1) 0.1% (Effective Output)
0.05% (8 Ω at 13W output)
0.05% (8 Ω at 1W output)
Output Bandwidth (IHF, both channel drives) 5 Hz ~ 40 kHz (Distortion Factor 0.1%)
Damping factor 30 (20 Hz ~ 20 kHz, 8 Ω)
Input Sensitivity / Impedance Phono : 2.5mV/50k Ω
Tuner, Aux, Tape play1, 2 : 150mV/50k Ω
Phono maximum allowable input 200 mv (1 khz, 0.1% harmonic distortion rate)
Output Level / Impedance Tape rec1, 2 : 150 mV
Speaker AORb : 4 Ω ~ 16 Ω
Speaker A + B : 8 Ω ~ 16 Ω
Headphone : 4 Ω ~ 16 Ω
Frequency characteristic Phono : 20 Hz to 20 kHz ± 0.3 dB
Tuner, Aux, Tape play : 10 hz to 40 khz + 0 -1dB
Tone control Bass:+9dB -8dB(100Hz)
Treble:+8dB -6dB(10kHz)
Loudness contour
(Volume -40dB)
+8dB(100Hz)
+5dB(10kHz)
S/N (IHF, A-network
Short circuit)
Phono:73dB
Tuner, Aux, Tape play : 93 dB
<General>
Semiconductor used Transistor : 25
IC : 2
Diode, etc. : 16 pcs
AC outlet Power switch interlock : 2 systems
Power switch not linked : 2 systems
Power supply voltage 100 VAC, 50Hz/60Hz
Power consumption 85W (Electrical Appliance and Material Control Law)
200W maximum
External dimensions Width 380x Height 139x Depth 306 mm
Weight 7.2kg