Pioneer SX-780 receiver

Pioneer SX-780 Stereo Receiver with Hybrid IC DC Amplifier Circutry, Latest Improvements in FM/AM Tuner Performance.

DC Power Amplifier

Pioneer's "DC with a Difference" Power Amp: no more "Mud" in Your Music.

When a musical signal enters the final power amplifier stage of the SX-780 and is given the "gain" (boost) it needs to drive your speaker systems, you can be sure that signal retains all the clarity and immediacy it had when it was originally delivered from your record, tape or broadcast. This is because the Pioneer DC design of the power amp uses no phase-delaying capacitors in the NFB or Negative Feedback loops, or in the final output stage. The main advantage is that TIM or Transient Intermodulation Distortion is reduced to negligible levels instantly; this, in turn, ensures that the "muddy" sound found in ordinary AC-type amps is gone forever. Unlike some other DC types however, Pioneer's design is "DC with a Difference". And that difference is that we retain the input capacitors to guarantee that absolutely no DC signal component can ever reach your speaker system to cause breakdown. Off/on switching noise, warped-record rumble and other undesiderable effects are also prevented, and frequency range is extended down to the very richest lows. And here's an important note: the SX-780 is the lowest-priced DC receiver in our entire lineup.

Hybrid IC Power Circuitry; More Efficiency, Less Cost

Improved circuit designs and the use of one hybrid IC per channel in the power output section of the SX-780 help reduce costs and raise efficiency. The ICs contain the bias, driver and output stages in a quasi-complementary circuit to feature high quality performance and long-life reliability. Power supply stability is ensured with one 8,000 µF electrolitic capacitor per channel.  All-new heat sinks improve efficiency.

 

FM Sensitivity is 1,8 µV ; A Meaningful Advantage

If the tuner or receiver you now own is more than a couple of years old, chances are it can't begin to compare with the SX-780 for high FM sensitivity, no matter how much you paid for it.  Only recently have our engineers developed circuitry to permit such high performance in pulling in the station you want with pinpoint accuracy; 1,8 µV or 10,3 dBf sensitivity in the SX-780 means better hi-fi FM sound in any reception area. A dual-gate MOS FET in the first stage of the three-transistor FM front end is part of our "secret"

 

Excellent Phase Characteristics in FM IF Amplifier.

Still more accuracy for better FM, capture ratio is an ideal 1,0 dB thanks to three two-pole ceramic filters with excellent phase characteristics in the IF amp. Circuited between them to achieve sufficient gain and better limiter characteristics is a special IC reflecting state-of-the-art. Circuit techniques.

 impressively Low Distortion and Noise in FM Performance

Still another Pioneer-exclusive IC, the PA-3001A, is found inn the SX-780 to improve FM performance. It includes the functions of FM discrimination, IF amplification and muting, and achieves a low distortion (at  65 dBf it is only 0,07%, mono 1 kHz) and a particularly high ratio of Signal-to-Noise Ratio . These specifications are the very best to be found in a receiver in this price range.

AM: The best Sound in Town

Pioneer has succeeded in eliminating the whine and boom of AM by packing the SX-780's AM tuner section with the very latest in special circcuitry. An IC (HA-1197), a newly-designed AM ferrite bar antenna, and other improvements help raise usable AM sensitivity to 300 µV/m and Signal-to-Noise Ratio to an excellent 50 dB. Low-frequency aound is especially clean.

Low Distortion Preamp

Musicality Guaranteed by Precision Phono Equalizer.

Dynamic range and frequency response are factors which are vital to accurate disc record reproduction, and both are maximized by the special circuitry in the phono equalizer of the Pioneer SX-780. a voltage-proof IC, the equivalent of 15 discrete transistors, is joined by precision RIAA components for long-life, high-quality reproduction with top musicality. Phono equalization is RIAA ±0,2 dB over the wide 20 to 20,000 Hz range. Phono overload is 200 mV, 1 kHz, 0,05% or less T.H.D.

 

Specifications

Amplifier Section

Continuous Power Output: 

45 watts per channel at 8 Ω  (20 - 20,000 Hz, 0,05% T.H.D.)

45 watts per channel at 4 Ω  (20 - 20,000 Hz, 0,08% T.H.D.)

Total Harmonic Distortion no more than 0,05% (continuous rated power output)

Intermodulation Distortion:  no more than 0,05% (continuous rated power output)

Damping Factor: 30

input Sensitivity/Impedance:

Phono :  2,5 mV/50 k Ω

AUX: 150 mV/ 50 k Ω

Tape Play 1, 2 :  150 mV/50 k Ω

Phono Overload Level:  200 mV ( 1 kHz  T.H.D. 0,05%)

Output Level/Impedance

Tape Rec 1, 2 :  150 mV

Speakers:  A, B, A +B

Headphones:  Low impedance

Frequency Response

Phono (RIAA EQ) :  20 to 20,000 Hz ±0,2 dB

AUX, Tape Play :  5 to 80,000 Hz +0 -1 dB

Tone Controls:

Bass :  +8 dB  -7 dB at 100 Hz

Treble :  +7 dB -6 dB at 10 kHz

Loudness Contour:  +6 dB (at 100 Hz) +3 dB (at 10 kHz)

Filter Low:  15 Hz (6 dB/oct)

Hum and Noise (IHF, short-circuited A network, rated power)

Phono :  76 dB

AUX, Tape Play :  95 dB

FM Tuner Section

Usable Sensitivity: 

Mono : 10,3 dBf (1,8 µV)

50 dB Quieting Sensitivity: 

Mono :  16,2 dBf (3,6 µV)

Stereo :  37,0 dBf (39 µV)

Signal-to-Noise Ratio

Mono :  80 dB

Stereo :  72 dB

Distortion (at 65 dBf)

Mono :  0,07% (at 100 Hz ); 0,07% (at 1 kHz); 0,12% (at 6 kHz)

Stereo :  0,15% (at 100 Hz); 0,15% (at 1 kHz ); 0,25% (at 6 kHz)

Frequency Response:  30 to 15,000 Hz +0,2 dB -0,8 dB

Capture Ratio:  1,0 dB

Selectivity:  75 dB

Alternate Channel Selectivity:  60 dB

Spurious Response Ratio:  65 dB

Image Response Ratio:  65 dB

IF Response Ratio:  90 dB

AM Suppression Ratio:  50 dB

Muting Threshold:  19,2 dBf (5 µV)

Stereo Separation:  45 dB (1 kHz); 35 dB (30 Hz -15 kHz)

Subcarrier Production Ratio:  55 dB

SCA Rejection Ratio:  65 dB

Antenna Input:  300 Ω  (balanced); 75 Ω  (unbalanced)

AM Tuner Section

Sensitivity:  300 µV/m (IHF, ferrite antenna); 15 µV (IHF, ext. Antenna)

Selectivity:  26 dB

Signal-to-Noise Ratio:  50 dB

Image Response Ratio:  40 dB

IF Response Ratio:  40 Hz

Antenna:  Built-in ferrite loopstick antenna

Semiconductors:  5 FETs; 11 ICs; 26 Transistors; 22 Diodes

Power Requirements:  110/120/220/240 V 50/60 Hz

Power Consumption:  150 W (UL), 280 VA (CSA)

Dimensions (W x H x D):  480 x 140 x 320 mm (18-7/8" x 5-1/2" x 12-5/8")

Weight:  12,8 kg (28 lb 3 oz)