Audio Database


Pioneer SX-818
100,000yen(1973 release)

The stereo receiver which adopted the whole page hardwired-connection pure complementary circuit.

The whole page hardwired-connection pure complimentary OCL scheme not using a coupling capacitor is used for a power amplifier part. Furthermore, two steps of differential amplifier was adopted and the high stability has been acquired also to the temperature change by applying a lot of negative feedback.

The full-scale thing which has the quick detection velocity which combined the power relay and the electronic circuitry is adopted as a protection network, and the power transistor and the speaker are protected from the unexpected trouble.
This protection network serves also as the power-source muting which is an auto-return type and removes the noise at the time of power activation.

The dual gate MOS FET and the 4-unit variable condenser which were selected carefully are combined with FM front end part, and radio-interference exclusion capacity is raised at the same time it obtains a high sensitivity and high S/N.

The FM IF section IC-ized the whole page, and the phase linear ceramics filter which cared about the phase response is adopted especially as a selection element. Moreover, IC for exclusive use is adopted as the FM MPX section, and the robustness is improved.

AM tuner part has an aligned type RF amplification using a triple variable condenser, and composition which uses IC and a ceramics filter for the IF section.

The equalizer-amplifier part has adopted the three-step hardwired-connection E-E feedback type by the silicon transistor of a low noise.

The control circuit serves as a NFB type which uses FET of a low noise for the first rank.

With the dimmer switch (dimmer switch) of a dial illumination, light and darkness can be chosen according to the luminosity of the room.

The audio muting, a pre / power amplifier splitting and a high / low filter, the selector indicator, etc. are carried.


Rating of a mode
Form FM / AM-stereo receiver
<FM tuner part>
Practical speed (IHF) 1.8 microvolts
Capture ratio (IHF) 1dB
Effective selectivity (IHF) 80dB
S/N 70dB
Image stonewalling ratio (82MHz) 90dB or more
IF stonewalling ratio (78MHz) 100dB or more
Spurious stonewalling ratio (82MHz) 100dB or more
AM supression ratio 55dB
THD (100% modulation) mono: 0.2% or less
stereo: 0.4% or less
Stereo separation 40dB or more (1kHz)
30dB or more (50Hz - 10kHz)
Carrier leakage supression ratio 65dB
Antenna 300-ohm balance type,
75-ohm unbalance type
Muting ON-OFF possible
<AM tuner part>
Practical speed (IHF) 15 microvolts
300 microvolt/m (bar antenna)
Selectivity 40dB
S/N 50dB
Image stonewalling ratio 65dB
IF stonewalling ratio 85dB
Antenna Ferrite bar antenna
<Power amplifier part>
Circuit system 2 steps of differentials whole page hardwired-connection pure complimentary
Effective output
20Hz - 20kHz, both channel drive : 65W+65W (4ohm)
55W+55W (8ohm)
1kHz, both channel drive : 75W+75W (4ohm)
60W+60W (8ohm)
1kHz, one-side-channel drive : 95W/95W (4ohm)
70W/70W (8ohm)
THD 0.3% or less (at the time of an effective output)
0.07% or less (at the time of 1W output)
Cross modulation distortion 0.3% or less (at the time of an effective output)
0.07% or less (at the time of 1W output)
Output bandwidth (IHF, both channel drive) 5Hz - 40kHz (0.3% of distortion)
Frequency characteristic 5Hz-80kHz+0 -1 dB
Input sensitivity/impedance 500mV / 50kohm
Output-terminal Speaker:A, B, C, A+B, A+C
Headphones: 4ohms - 16ohms
Dumping factor (1kHz, 8ohm) 40 or more
S/N 95dB or more (IHF, short circuit, and A network)
Remains noise (8 ohms, pre + power amplifier) 1mV or less
<Preamplifier part>
Circuit system Equalizer amplifier: Three-step hardwired-connection NF type
Control amplifier: First rank FET NF type
Input sensitivity/impedance Phono1:2.7mV/50kohm
Phono2 MC: 115 microvolts/30 ohms (at the time of the input transformer PP-402 using for MC)
Mic: 2.6mV / 50kohm
Aux, Tape1, 2, Din:200mV /, 100kohm
Phono maximum permissible input (rms/p-p) 130mV/360mV
An Output voltage/impedance Tape rec1, 2:200mV
1 (Din):35mV of Tape rec / 85kohm
Pre out: 500mV/300 ohms
THD (20Hz - 20kHz) 0.1% or less
Frequency characteristic Phono(RIAA deflection): 30Hz-15kHz}1dB
Mic: 20Hz-20kHz}1dB
Aux, Tape:10Hz-40kHz}1dB
Tone control Bass: }10dB (100Hz)
Treble: }10dB (10kHz)
Filter Low: 60Hz, 12dB / oct
High: 6kHz, 12dB / oct
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
Aux, Tape: 90dB or more
Muting -20dB
Power consumption 150W (rate)
370W (maxima)
Dimensions Width 485x height 150x depth of 375mm
Weight 14.8kg