What is stereo?




There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.




H.H. Scott '59





Technics SA-828


Quartz synthesizer digital tuning provides exact and drift-free reception. A choice of three tuning modes: 14 preset stations (7 FM and 7 AM), up/down manual, and auto-scan. Digital frequency readout plus analog display. LEDs for signal strength, quartz-lock and preset channels. New Class A and Linear feedback amplifier design. Space Dimension Control expands the stereo image to a maximum of 240°. Dimension and power level dispaly. Input-capacitorless phono equalizer first stage allows direct MC cartridge connection. Electronic protection circuit. Protection/safety indicators. Two-way tape dubbing IF band selector. Soft touch volume control.

Beyond quartz, the world's most precise tuning system, lies a new ability to expand sound.
Imagine you're in a room with Technics SA-828 receiver.
What you hear is beautiful stereo. Then you activate Technics variable Dimension Control. Incredibly, the sound begins to move. The stereo image widens to the point where the music begins to surround you. You're intrigued by its richness and depth. You're enveloped by a new experience in sound. That's the wonder of the patented technology in Technics Dimension Control.
Just as wondrous is quartz synthesis, the world's most precise tuning system. That's how the SA-828 quartz synthesizer eliminates FM drift as well as the hassle of tuning. You can even preset and instantly retrive 7 FM and 7 AM stations, all perfectly in tune.

Another perfect example of Technics technology is our synchro-bias circuitry. What it does is constantly  send minute amounts of power to the amplifier transistors. And since they can't switch on or off, switching distortion is eliminated.
And when it comes to power, thr SA828 has plenty;  100 watts per channel minimum RMS into 8 ohms from 20 Hz to 20 kHz with no more than 0,005% total harmonic distortion.
The SA-828 goes on to show its sophistication with a super-quiet phono equalizer, soft touch program selectors, fully electronic volume control, and a Dimension Control display that doubles as a power level meter.


Specifications
Power Output (min. RMS per channel, 8 ohms, both channel driven):
100 W per chennel, from 20 Hz to 20 kHz
Continuous Power Output:
105 W per channel  at 8 ohms (1 kHz, 0,001% T.H.D.)
Dynamic Headroom:  1,3 dB (8 Ω)
Total Harmonic Distortion: 
Rated Power at 20 Hz to 20 kHz :  0,005% (8 Ω)
Half Power at 20 Hz to 20 kHz :   0,005% (8 Ω)
Half Power at 1 kHz :  0,01% (8 Ω)
Intermodulation Distortion SMPTE :  0,01% 98 Ω)
Frequency Response
Phono :  RIAA standard curve ±0,2 dB
Aux, Tape :  5 Hz - 100 kHz - 3 dB (20 Hz - 20 kHz, +0,2 dB, -0,2 dB)
Input Sensitivity
Phono MC :  17 µV 9170 µV, IHF'66)
Phono MM :  0,25 mV (2,5 mV, IHF ;66)
Aux, Tape :  15 mV (150 mV, IHF '66)
Signal-to-Noise Ratio (IHF A)
Phono MC :  75 dB (70 dB, 250 µV input Ihf '66)
Phono MM :  78 dB (87 dB IHF '66)
Aux, Tape :  80 dB (110 dB, IHF '66)
Maximum Input Voltage
Phono MC :  10 mV (11 mV, 1 kHz)
Phono MM :  145 mV 9160 mV, 1 kHz)
Input Impedance
Phono MC :  47  Ω
Phono MM :  47 k Ω
Aux, tape :  22 k Ω
Tone Control
Bass :  50 Hz +10 dB -10 dB
Treble :  20 kHz +10 dB -10 dB
Subsonic Filter:  30 Hz, -6 dB/oct
High Filter:  7 kHz -6 dB/oct
Loudness Control (vol. At - 30 dB):  50 Hz +9 dB
Muting:  -20 dB
Output Voltage
REC Out :  150 mV
Low Frequency damping Factor:  40 at 8 Ω; 20 at 4 Ω
Load Impedance
Main or Remote :  4 - 16 ohms
Main and Remote :  8 - 16 ohms
FM Tuner Section
Frequency Range:  87,9 - 107,9 MHz or 87,5 - 108,0 MHz
FM Sensitivity:  10,8 dBf (1,9 µV )
50 dB Quieting Sensitivity
Mono :  13,7 dBf (2,7 µV)
Stereo :  37,2 dBf (39,7 µV)
FM T.H.D.
At 100 Hz [mono/stereo]:  0,08% / 0,15%
At 1 kHz [mono/stereo]:  0,08% / 0,1%
At 6 kHz [mono/stereo]:  0,2 % / 0,2%
Signal-to-Noise
Mono :  77 dB
Stereo :  71 dB
Capture ratio:  1,2 dB
Alternate Channel Selectivity: 
Wide ±400 kHz :  75 dB
Narrow ±300 dB :  80 dB
Frequency Response:  20 Hz - 15 kHz, +0,2 -0,8 dB
Image rejection at 98,1 MHz :  80 dB
IF Rejection at 98,1 MHz :  90 dB
Spurious Response rejection at 98,1 MHz :  100 dB
Am Suppression:  60 dB
Stereo Separation
At 1 kHz :  45 dB
At 10 kHz :  40 dB
Carrier Leak
At 19 kHz :  -65 dB
At 38 kHz :  -70 dB
Antenna Terminals:  300 Ω (balanced); 75 Ω (unbalanced)
AM Tuner Section
Frequency Range:  530 - 1620 kHz or 522 - 1611 kHz
Sensitivity:  30 µV ; 250 µV/m
Selectivity:  56 dB
Image Rejection at 1000 kHz:  50 dB
IF rejection at 1000 kHz :  40 dB
General
Power Supply:  AC 120 V 60 Hz or 120 V/ 230 V 50/60 Hz
Power Consumption:  400 W, 500 VA
Dimensions (W x H x D):  530 x 181 x 388 mm (20-7/8" x 6-11/32" x 15-9/32")
Weight:  15 kg (33,1 lbs)

Onkyo TX-850


Important Features:
Discrete Output Stage:
Instead of IC power amp circuitry, the TX-850 both employ a discrete output stage for effortless drive into low impedance loads. Low distortion linear switching and the high quality parts used throughout are proof of Onkyo's dedication to audio excellence not merely in its high end amps but across the board.
"CD Direct" Switch:
This switch lets the user bypass the tone and balance controls in the amplifier when listening to CD (or other digital audio sources).since noise levels in digital audio are extremely low, sending and switching the audio signal through tone and balance circuitry is often unnecessary and may even adversely alter the high quality digital signal.
APR (Automatic Precision Reception) System:
Onkyo's exclusive APR precision reception system lets every FM broadcast sound its best. Intelligent circuitry monitors the signal and selects the optimum settings for three reception modes: stereo/mono, hi-blend on/off and local/DX mode, the system controls the noise reduction on/off mode as well.  The APR system settings are shown by indicators on the front panel.
Other Features:
20-station FM/AM Random memory with Battery Free Backup
Full Logic Selector Keys for Seven Input Sources Including Video Input and Dubbing Capabilities
Dynamic Bass Expander and Stereo Image Expander
Selective Tone Control
Sleep Timer (max. 90 minutes, also operable via remote control)
Simulated Stereo
Remote Controlled Motor Driven Volume Control
System Remote Control Possible with Onkyo Components

Specifications:
Amplifier Section
Power Output:  68 watts per channel, min. RMS, at 8 Ω both channels driven, from 20 Hz to 20 kHz with no more than 0,04% T.H.D.
Total Harmonic Distortion:  0,04% at rated power
IM Distortion:  0,04% at rated power
Damping Factor:  40 at 8 Ω
Frequency Response:  20 - 30,000 Hz ±1 dB
RIAA Deviation:  20 - 20,000 Hz ±0,8 dB
Sensitivity and Impedance:
Phono :  2,5 mV/ 50 k Ω
CD/Tape Play :  150 mV/50 k Ω
Tape Rec :  150 mV/ 3,5 k Ω
Phono Overload:   120 mV RMS at 1 kHz, 0,04% T.H.D.
Signal-to-Noise Ratio:
Phono :  85 dB (at 10 mV input, A weighted);  75 dB (IHF-A 202)
CD/tape :  85 dB (A weighted);  80 dB (IHF-A  202)
Tone Controls:
Bass :  ±10 dB at 100 Hz
Treble :  +_10 dB at 10 kHz
FM Tuner Section:
Tuning Range:  87,9 - 107,0 MHz (200 kHz steps) and/or 87,5 - 108,0 MHz (50 kHz steps)
Usable Sensitivity
Mono :  10,8 dBf (1,9 µV)
Stereo :  17,2 dBf (4,0 µV)
50 dB Quieting Sensitivity
Mono :  17,2 dBf (4,0 µV)
Stereo :  37,2 dBf (40 µV)
Capture Ratio:  1,5 dB
Image rejection ratio:  40 dB
IF Rejection ratio:  90 dB
Signal-to-Noise Ratio: 
Mono :  73 dB
Stereo :  67 dB
Alternate Channel Attenuation:  55 dB
AM Suppression Ratio:  50 dB
Harmoni Distortion:
Mono :  0,15%
Stereo :  0,25%
Frequency Response:  30 - 15,000 Hz ±1,5 dB
Stereo  Separation:  45 dB at 1 kHz; 30 dB at 100 - 10,000 Hz
Muting Level"  17,2 dBf (4 µV)
AM Tuner Section
Tuning Range:  530 - 1620 kHz (10 kHz steps) and/or 522 - 1611 kHz (9 kHz steps)
Usable Sensitivity:  30 µV
Image rejection ratio:  40 dB
IF Rejection ratio:  40 dB
Signal-to-Noise Ratio: 40 dB
Harmonic Distortion:  0,7%
General Section
Power Supply:  AC 120V, 60 Hz and/or 120V and 220 V switchable, 50/60 Hz
Dimensions (W x H x D):  435 x 130 x 351 mm (17-1/8" x 5-1/8" x 13-13/16")
Weight:  8,8 kg 919,4 lbs)

Remote Control (RC-118S)

Marantz SR-50L

 Stereo Receiver with Digital AM/FM Stereo Tuner
Specifications 
FM Tuner Section
Frequency Range:  87,5 - 108 MHz
Sensitivity DIN (Mono/Stereo):  1,2 / 25 µV
Signal-to-Noise  Ratio (Mono/Stereo):  76 / 68 dB
Total Harmonic Distortion : 0,2/0,4 %
Selectivity at 98 MHz (± 300 kHz):  60 dB
MW Tuner Section
Frequency Range:  531 - 1602 kHz
Sensitivity (S/N  20 dB 30% 1 MHz):  500 µV
Signal-to-Noise Ratio at 1 MHz:  50 dB
LW Tuner Section
Frequency Range:  152 - 282 kHz
Sensitivity (S/N 20 dB 30% 1 MHz):  1000 µV
Amplifier Section
Power Output
DIN at 8 Ω  :  50 W
RMS at 8 Ω  :  40 W
Total Harmonic Distortion (at 8 Ω rated RMS output):  0,09%
Damping Factor:  50
Input Sensitivity
Phono :  3,5 mV/47 k Ω
CD, Tape, CDV, VCR :  220 mV/47 k Ω
Signal-to-Noise Ratio (IHF-A):
Phono :  76 dB
CD, Tape, CDV, VCR :  86 dB
Power  Supply:  AC 220V 50/60 Hz
Dimensions (W x H x D):  420 x 118 x 334 mm
Weight:  6,5 kg

Supplied Accessories:  Remote controller RC-60SR

Audio Research SP11

 The SP11 is a hybrid unit, utilizing both vacuum tubes and FETs (Fiel Effect Transistors). It is not intended that this product should somehow continue the controversy of "vacuum tubes" vs. "solid-state". Rather, in keeping wit Audio Research's design philosophy of advancing the state-of-the-art., each type of device is used where it performs best.
One important result, aside from the dramatically improved quality of sound reproduction, is the use of only six vacuum tubes - tubes which need not be selected low-noise types. A significantly longer time between tube replacement is also expected.
As a last word, this preamplifier may well change your thinking about music reproduction. Because it is so incredibly "open" sounding, much information not previously sudible is available, providing new insight and enjoyment from many sound sources. To be appreciated, the SP11 preamplifier must be personally experienced; it cannot otherwise be adequately related.
 Operational Features:
Automatic warmup, brown-out power-line interruption muting and manual muting at all preamplifier outputs, with new shunt circuitry.
Subsonic phono filter with 6 dB /oct rolloff (to eliminate ringing) with transition to 12 dB/octave.
Bypass switch for use with "audiophile quality" program material.
Absolute phase switch for main outputs, plus unswitched inverting and non-inverting outputs.
Full tape functions; two inputs, two recording outputs, plus tape copy and tape monitor functions.
Input/output connectors have heavy gold plating and connect "ground" before "hot".
Level set control in addition to normal gain control. Allows essentially unlimited input signal range while preserving optimum gain control usage.
Toroid power transformer for low mechanical noise and low external magnetic field.
 In Octobr of 1985, Audio Research Corporation introduced the SP11 preamplifier. During the first year, our introductory claim of "a new reference standard" has been confirmed by reviewer after reviewer throughout the Free World.. It is improbable that any audio product, including previous Audio research products, has ever received such unanimous acclaim. We believe that once you hear the SP11 reproduce music, you will find that acclaim justified.

Specifications
Frequency Response:
High Level Input :  0,2 Hz to 100 kHz ±1 dB (-3 dB below 0,1 Hz and above 200 kHz)
Phono Input:  20 Hz to 40 kHz ±2 dB of RIAA (±1 dB of RIAA, 1,0 Hz to 100 kHz)
Harmonic Distortion:  less than 0,005% at 2 V RMS output, 5 Hz to 20 kHz (Typically less than 0,001% at midband, phono or line input)
Intermodulation Distortion:  less than 0,003% at 2 V RMS output
Gain (aat 1 kHz , bypass mode):
Phono Input to Tape Output :  46 dB (0,2V output from 1mV input)
Phono Input to Main Output :  75 dB (0,175 mV input for 1 V output)
High Level Input to Main Output :  29 dB (36 mV input for 1 V output)
Inputs:  Phono, Tuner, CD, Video, Spare, Tape 1, Tape 2,
Outputs:  Tape 1, Tape 2, Main 1, Main 2, Direct, Invert
Filter:  25 Hz Hi-pass phono subsonic 6 dB/octave rolloff (to eliminate ringing) with transition to 12 dB/octave at 10 Hz. Front panel switchable, phono only
Controls:  Gain, level (to set gain Range), balance, Mode, Input, Impedance
Switches: Tape Monitor, Copy, Tape 1/2, Tape 1 to 2/2 to 1, Mute, Invert Phase,Bypass, Filter
Input Impedance:
Phono :  47 k Ω, 100, 30, 10, 3 Ω (front panel selectable)
Phono Input Capacitance:  150 pF at 10 kHz
High Level:  20 k Ω or higher, depending on switch functions
Maximum Inputs Level Undistorted:
Phono :  350 mV RMS at 1 kHz, 1200 mV RMS at 10 kHz (0,1 second maximum duration, 6 dB less if continuous)
High Level :  25 Volts RMS
Output Impedance:  250 Ω main, direct, invert outputs, 500 Ω tape output. Recommended load 60 k Ω and 100 pF (25 k Ω minimum, 1000 pF maximum)
Rated Output:  2V RMS 1 Hz to 100 kHz main, direct, invert outputs (Maximum 80 V RMS output at 0,2% T.H.D. at 1 kHz into 60 k Ω load with 2,85 V RMS high level input)
Phase:
Tape Outputs, Direct Output;  Non-inverting
Invert Output :  Inverting
Main Outputs :  selectable non-inverting or inverting. All outputs may be used simultaneously.
Noise (IHF Weighted, shorted input):
Output (Gain down) :  6 µV (110 dB below rated output)
Input High Level) :  3 µV equivalent input (110 dB below 1 V input)
Phono :  0,15 µV equivalent input (76 dB below 1 mV input)
Tube Complement (Hybrid FET/Tube Audio Circuit, Solid-State Power Supply):  6 - 6DJ8/ECC88
Power Requirements:  95 - 135 V AC 60 Hz (Export 190 - 270 v AC 50/60 Hz)
Power Consumption:  130 watts maximum
Dimensions (W x H x D) Each Chassis, EIA Rack panel Mounting:
480 x 134 x 260 mm (19" x 5,25" x 10,25")
Weight Net:
SP11 :  6,4 kg (14 lbs)
SP11PS :  6,8 kg (15 lbs)