Pioneer SX-80

Commentary

AM/FM multi integrated stereo amplifier equipped with stereo / mono automatic switching mechanism.

The FM tuner uses a front end of the cascode system combined with a 3-row varicon using a Newby star. This part is also thoroughly shielded to minimize unwanted radiation (spurious).
The IF amplifier consists of four stages, and the FM detector uses a wide-band ratio-detection method suitable for FM stereo broadcast transmission reception. The AFC circuit ensures stable broadcast reception at all times.
In addition, it is equipped with 3 stages of limiter circuit to remove noise, and it always promises beautiful broadcast reception.

It is equipped with a muting circuit, and noise between stations can be removed.

Switching system is adopted for FM multi-circuit.
The stereo indicator lights during FM stereo reception.

It is equipped with an automatic mono-stereo switching mechanism. If the selector knob is set to FM-AUTO, it automatically switches to stereo when an FM stereo broadcast transmission is received.

The AM tuner uses a 3-row varicon with excellent selectivity, and a compact bar antenna with ferrite core is used for the antenna. In areas near broadcasting stations and with strong radio waves, you can receive signals without using an external antenna.
The intermediate frequency section is equipped with a Sharp-Broad switch that allows you to change the sound quality according to your preference.

With a built-in equalizer for NAB characteristics, you can easily play 4-track recorded tapes by directly connecting the head output of the tape deck (dedicated playback machine).

For the output stage of the main amplifier section, high efficiency tube 7189A with good sound quality is adopted by fixed bias system push-pull.
A large transformer with good characteristics is used for the output transformer.

It has a headphone port.

It features a speaker ON/OFF switch, low / high filter, loudness contour, muting circuit, etc.

Model Rating

Type	AM/FM multi-integrated stereo amplifier
Tuner Section
Circuit system	RF-Tuned Front End Cascode Using 3-Series Variable Capacitor 3-stage limiter out of 4-stage intermediate frequency Wide-band ratio detection and muting circuit
Receiving band	FM : 76 MHz to 90 MHz AM : 535 kHz to 1605 kHz
Intermediate frequency bandwidth	FM : ± 100 kHz (-3dB) AM BROAD : ± 7 kHz (-3dB) SHARP : ± 4 kHz (-3dB)
Practical sensitivity (IHF)	FM : 2 μ V AM : 10 μ V
Image ratio	FM:50dB(82MHz) AM:70dB(1000kHz)
Antenna input impedance	FM : 300 Ω Balanced Type
Accessory circuit	AM ferrite loop stick antenna FM multi-circuit FM AFC
<FM Multi Section>
Circuit system	Switching system With Stereo-Mono automatic switching device Stereo indicator SCA Filters
Channel separation	35dB(1kHz) 25 dB or More (30 Hz to 10 kHz)
Amplifier Unit
Circuit system	7189A AB PP
Effective power	30W + 30W (Distortion Factor 1% or Less, 1 kHz)
Music power	70W (Distortion Factor 1% or Less, IHF)
Frequency characteristic	20 Hz to 20 kHz
Output bandwidth	30 Hz ~ 15 kHz (Constant Distortion Rate of 1%, IHF Standard)
Signal-to-noise ratio Volume Max, Tone Mid, Effective Power, IHF	Aux:75dB Phono MAG:65dB
Input terminal	Phono MAG:3mV Phono CER/X-tal:30mV Tape head:2mV Aux, Tape playback (Tape monitor) : 150 mv
Equalizer	Phono MAG : NF Type Tape head:NAB
Tone control	Bass : ± 15 dB (50 Hz) Treble : + 10 dB ~ -12dB (10 kHz)
Loudness contour	ON-OFF enabled
Filter	Low:-8dB(50Hz) High:-14dB(10kHz)
Output terminal for speaker	8 Ω ~ 16 Ω
Stereo headphone jack	Always available when the amplifier is operating With Speaker ON/OFF Switch
Residual noise	2 mv (8 Ω, Volume Min, Tone Mid Point)
<General>
Vacuum tube used	Vacuum Tubes (20 pcs) : Others (14 pcs) : 7189Ax4 12AX7x3 6AN8x3 6BA6x3 6AQ8x3 6BE6x1 6AU6x1 6EA8x1 6CW4x1 OA79x8 OA70x1 MP-03x1 SD-1Ax2 IS85x1 2SB54x1
Power supply voltage	100 VAC / 117 V, 50Hz/60Hz
Maximum Power Consumption	170W
Maximum external dimensions	Width 445x Height 150x Depth 440 mm
Weight	18kg