Audio Database


Pioneer SA-710
54,000yen(around the 1973 time)

The stereo Integrated Amplifier which adopted the whole page hardwired-connection pure complimentary OCL scheme.

The PNP type low-noise transistor selected carefully to the first rank was used for the equalizer part, and the three-step hardwired-connection amplifier which inserted the emitter follower circuitry in the 2nd step is used for it.
Since the gain of the first rank can take greatly, the terms and conditions of a low noise and the head amplifier of high gain are fulfilled.

In order to press down the deflection of a RIAA play curve thoroughly, the nichrome vapor-deposition metal film resistor of 1% of an error and the styrene capacitor of 2% of an error are adopted as the NFB element of an equalizer, and the element of the fraction which receives NFB.

In a control amplifier part, since high FET of the input impedance was adopted as the first rank, even if the coordination location of volume control is in which point, that of a noise transition does not occur.

Since the turnover switchpoint which became independent, respectively is carried in Bass and Treble and a turnover frequency can be chosen independently, respectively, the tone control united with the property of the source and the effect can be performed.

Regardless of the location and tone property of a turnover, the tone-defeat switchpoint which can choose a tone flat by one-touch is carried.

The power circuitry has adopted the 1 step of differential whole page hardwired-connection pure complimentary OCL scheme.
Since direct-current stability is fully taken by adoption of the temperature warranty circuitry of the bias of the first rank in addition to one step of differential amplifier, the zero potential of an outputting point does not collapse in a big temperature change, either.
Moreover, the degree of safe is high at a using of a power transistor with high large-sized radiator and destructive intensity, and it is obtained where high power is stabilized.

PNP and the NPN transistor to which the pair property was equal are adopted as a driver and a power transistor.
Furthermore, the degree of safe is high by adoption of the large-sized radiator and current-limiting circuitry and the electronic formula protection network.

Those with 2 circuitries and a duplicate are also possible for a TapeMon termination.
Furthermore, the independence of A, B, and A+B and the speaker termination of two circuitries which can perform a combination performance are equipped.

The Subsonic Filter (5Hz, 12 dB/oct) which cuts a super-low-pass unnecessary noise is built in.

The protection network which combined the electronic circuitry and the power relay is adopted. The indicator which tells it at the time of an operation of this protection network lights up.
Moreover, it serves also as the power-source muting which banishes the shocking noise at the time of power activation.

The survey data measured for every set is attached.


Rating of a mode
Form Stereo Integrated Amplifier
<Power amplifier part>
Circuit system 1 step of differential whole page hardwired-connection pure complimentary OCL
Effective output
20Hz - 20000Hz, both channel drive : 20W+20W (8ohm)
24W+24W (4ohm)
1kHz, both channel drive : 22W+22W (8ohm)
30W+30W (4ohm)
1kHz, one-side-channel drive : 25W/25W (8ohm)
36W/36W (4ohm)
THD At the time of an effective output: 0.5% or less
At the time of 1W output: 0.05% or less
Cross modulation distortion At the time of an effective output: 0.5% or less
At the time of 1W output: 0.1% or less
Output bandwidth (IHF, both channel drive) 5Hz - 70kHz (0.5% of distortion)
Frequency characteristic 7Hz - 80kHz, and +0 -1 dB
Input sensitivity/impedance Power Amp In: 500mV / 50kohm
Output-terminal Speaker:A, B, A+B (4ohm-16ohm)
Head Phones: 4ohm - 16ohm
Dumping factor (1kHz, 8ohm) 40 or more
S/N 90dB or more (IHF, short circuit A network)
Remains noise (8 ohm, pre + power amplifier) Below 1mV (0.13 microwatt)
Subsonic Filter 5Hz(12dB/oct)
<Preamplifier part>
Circuit system Equalizer amplifier: Three-step hardwired-connection NF type
Control amplifier: First rank FET, NF type
Input sensitivity/impedance Phono1:2.5mV/50kohm
Phono maximum permissible input (rms/p-p): 190mV/530mV
MIC: 2.0mV / 50kohm
Tuner: 150mV / 100kohm
Tape Monitor1, 2:150mV / 100kohm
2 (DIN):150mV of Tape Monitor / 100kohm
An Output voltage/impedance Tape Rec1, 2:150mV
2 (DIN):30mV of Tape Rec / 80kohm
Pre Out: 500mV / 1.5kohm
THD (20Hz - 20kHz) 0.1% or less
Frequency characteristic Phono (RIAA deflection): 30Hz - 15kHz, }0.2dB
MIC: 15Hz - 10kHz, and +0 -1dB
Tuner, AUX, TapeMonitor: 15Hz - 30kHz, and +0 -1 dB
Tone control
Bass }6.5dB (100Hz)
}10dB (100Hz)
200Hz of turnover frequencies, 400Hz
Treble }7.5dB (10kHz)
}10.5dB (10kHz)
5kHz of turnover frequencies, 2.5kHz
Loudness contour (volume 40dB o'clock) + 10dB (100Hz), 6dB (10kHz)
S/N (IHF, short circuit)
A network
Phono: 80dB or more
MIC: 70dB or more
Tuner, AUX, Tape Monitor: 90dB or more
Muting -20dB
The semiconductor used FET:2
Transistor: 33
Diode, others : 24
Supply voltage AC100V, 50Hz/60Hz
Power dissipation 55W
Maximum electric power consumption 180W
Power receptacle Power-switch interlock 1. Un-interlocking 2.
Dimensions Width 430x height 138x depth of 341mm
Weight 10.1kg