Pioneer SA-6700

Commentary

A pre-main amplifier with low cost, high power and low distortion.

All stages are directly connected and pure complimentary service OCL circuit is adopted for the circuit system of power amplifier.
This circuit uses a newly developed 4-chip hybrid IC after the driver stage. Specially selected ICs are used to improve the characteristics. In addition, the differential circuit uses a dual transistor that combines two transistors with the same characteristics into a single pair to achieve stable operation.

The equalizer uses a 3-stage direct-coupled circuit with ± 2 power supply.
Since this circuit can take a large gain at the first stage, stable NFB can be sufficiently applied, and low distortion rate and high SN ratio are achieved.
The ± 2 power supply keeps the input and output points at 0 potential to eliminate unpleasant shock noise when switching.

The volume uses a full-scale 32-step attenuator, which ensures that the left / right linkage error is within ± 0.5 dB over the range from 0 to -70dB.

The control amplifier section is designed with a CR-type tone control circuit connected to the second stage of the 2-stage direct amplifier.
This circuit can sufficiently apply NFB and realizes frequency characteristics with little distortion.

The tone control is an 11-position click-stop type.
It also has an on/off switch, which can pass the tone control circuit by turning it off.

Equipped with a full-scale protection circuit that combines an electronic circuit and a relay.
It also functions as a muting to remove noise when the power is turned on/off.

Two 8,000 μ F electrolytic capacitors are used for the power supply.

Equipped with a low-cut filter.

The wood case with walnut finish that can be used for SA-6300, TX-6300, SA-6700, TX-6700 was sold separately.

Model Rating

Type	Stereo pre-main amplifier
Circuit system	Pure complimentary service OCL
Effective output (both channels driven, 20 Hz to 20 kHz)	40W + 40W (4 Ω) 35W + 35W (8 Ω)
Harmonic distortion factor (20 Hz to 20 kHz)	0.1% or Less (Effective Output) 0.08% or Less (8 Ω at 20W output) 0.05% or Less (8 Ω at 1W output)
Cross modulation distortion factor	0.1% or Less (Effective Output) 0.08% or Less (8 Ω at 20W output) 0.05% or Less (8 Ω at 1W output)
Output Bandwidth (IHF, both channel drives)	5 Hz ~ 30 kHz (Distortion Factor 0.1%)
Output terminal	Speaker A / B : 4 Ω ~ 16 Ω Speaker A + B : 8 Ω ~ 16 Ω Headphone : 4 Ω ~ 16 Ω
Damping factor (20 Hz to 20 kHz)	25 or More (8 Ω)
Input Sensitivity / Impedance	Phono : 2.5mV/50k Ω Tuner, Aux, Tape PB1, 2, DIN : 150mV/50k Ω
Phono maximum allowable input (harmonic distortion rate 0.1%)	200mV(1kHz)
Output Level / Impedance	Tape Rec1, 2 : 150 mv Tape Rec2 (Din) : 30mV/80k Ω
Frequency characteristic	Phono (RIAA deviation) : 30 Hz to 15 kHz ± 0.3 dB Tuner, Aux, and Tape PB : 10 hz to 50 khz + 0 to 1.0 db
Tone control	Bass : ± 9 dB (100 Hz) Treble : + 8 to -6dB at 10 kHz
Filter	Low : 15 Hz, 6dB/oct.
S/N (IHF, A-Network, short circuit)	Phono : 70 dB or more Tuner, Aux, Tape PB : 90 dB or higher
<General>
Semiconductor used	Transistor : 20 IC : 4 Diode, etc. : 16 pcs
AC outlet	Power switch interlock : 2 systems Power switch not linked : 1 system
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	90W (rated) 255W maximum
External dimensions	Width 350x Height 125x Depth 282 mm
Weight	7.6kg
Sold separately : Wood Case JA-C60 (¥ 4,500)
External dimensions	Width 404x Height 167x Depth 276 mm
Weight	2.2kg