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





Toshiba SA-850 receiver

Digital Synthesizer Stereo Receiver

Absolutely Precise Digital Synthesizer Tuning with 12 memory Positions, 4 Instant Selection of 6 FM and 6 AM Stations.

Beautifully styled with walnut side panels and brushed aluminum front panels. Lower half of front panel disappears into the unit to expose less often used controls. Double-pair speaker selection, tone control defeat (flat) switch, subsonic filter, loudness switch, stereo/mono mode selection, push-button source selection with full tape monitoring/duplicating facilities including a source-on/recording-off position.

Green LED tuner frequency, signal-strength, stereo and band displays. All push-button tuning system using quartz crystal digital synthesizer system providing manual and automatic tuning with six each preset memory stations for FM and AM.

A professional 41-position click-stop volume control is conveniently located at the upper right. Superb craftsmanship coupled with advanced technology -  the essence of Toshiba's attitude toward high fidelity component design.

 

Quartz Reference Frequency Synthesizer Tuner

Both the FM and AM tuner sections make use of quartz crystal reference frequency and digital frequency synthesizer circuits with PLL system to insure essentially perfect station tuning each and every time. What's more, the ultra-stable control voltage of the PLL is used to tune the 3-gang variable capacitance diodes of the front-end for excellent sensitivity and adjacent channel rejection. This means more received signal power for higher Signal-to-Noise Ratio and less phase distortion than from conventional tuners.

 


Manual and Automatic Tuning

You get your choice of tuning either manually or automatically with push-button selection. In the manual mode, you can tune up or down the FM band in 0,1 MHz increments while for AM, the increments are 1 kHz. In the automatic mode (FM :  Auto Tuning, AM : 10 kHz step tuning), you have a choice of any of six present stations and this holds true for either AM or FM giving you twelve preset stations in all. And more, presenting the station frequency is just as simple by manually tuning to the desired station and pressing two buttons (memory and channel). Channel frequencies are retained with power off and even for a good time with the power cord removed from the outlet.

 

Clean Stereo Amplification for Low Noise at High Power Levels

Full-complementary direct-coupled power amplifiers provide 50 Watts rms power per channel into 8  and are driven by low distortion differential amplifiers and powerful Darlington drivers with plenty of feedback for inaudible distortion. Clean power supply designs using an extra-large triple-secondary power transformer and twin 10,000 µFd filter capacitors keep power line noise and hum out of the outputs and prevent back-coupling to the low level preamp and tuner stages.

 

Full Tape Monitoring/Duplicating

You get provisions for attaching two three-head (or other) tape decks to the SA-850 with full monitoring provisions plus duplicating switching between the decks either way, 1 to 2 or 2 to 1. and, to isolate the input amplifiers of the decks when their power is off, a special intermediate source monitoring switch position (REC OFF) has been added which eliminates the record output signals to the decks.

 

Wide Range Sound Quality Controls

A large 41-position click-stop volume control is conveniently located at the top, right of the SA-850 to give you level control capability. Twin-pair speaker selection switching lets you fully utilize speakers in remote locations and provides silent operation for use with headphones. Bass/treble controls can be defeated by just loudness control. A subsonic filter eliminates rumble and other low frequency player/disc problems which occur occasionally and a mode switch permits monaural deck playback through both speakers.

 


Specifications

Main Amplifier Section

Power Output (Both Channels Driven):  continuous power output of 50 Watts per channel , minimum rms int 8  from 20 to 20,000 Hz and with no more than 0,03% T.H.D.

55 watts into 8  at 1t 1,000 Hz

Total Harmonic Distortion( (20 to 20,000 Hz, 8 )

0,03% or less at 50 Watts per channel

0,02% or less at 25 Watts per channel

0,02% or less at 1 Watt per channel

Intermodulation Distortion (50 Hz : 7000 Hz signals mixed at 4 : 1 , at 8 )

0,03% or less at 50 Watts per channel

0,02% or less at 25 Watts per channel

0,02% or less at 1 Watt per channel

Power Bandwidth:  10 to 35,000 Hz

Residual Noise:  0,5 mV rms into 8

Damping Factor:  50

Preamplifier Section

Frequency Response

Aux :  10 to 40,000 Hz +0,5, -1,0 dB

Phoo :  20 to 20,000 Hz ±0,3 dB

T.H.D:  0,025 % or less

Subsonic Filter:  16 Hz , 6 dB/oct

Signal-to-Noise Ratio

Phono :  78 dB (2,5 mV), 90 dB (10 mV)

Tape/AUX :  95 dB

Phono Overload Level:  200 mV rms 1,000 Hz

Input Sensitivity/Impedance

Phono :  2,5 mV/47 k

Tuner/AUX :  150 mV/47 k

Tape :  150 mV/47 k

Output Level: 

Tape Rec :  150 mV

Tone Control

Bass :  ±10 dB at 100 Hz

Trebble :  ±10 dB at 10,000 Hz

Loudness Control (-40 dB position)

+8 dB at 100 Hz;  +4 dB at 10,000 Hz

FM Tuner Section

Usable Sensitivity:  10,3 dBf (1,8 µV)

50 dB Quieting Sensitivity:

Stereo :  38,2 dBf (45 µV)

Mono :  15,3 dBf (3,2 µV)

Signal-to-Noise Ratio

Stereo :  68 dB

Mono :  72 dB

Distortion (1,000 Hz )

Stereo :  0,2%

Mono :  0,15%

Frequency Response:  20 to 15,000 Hz +0,5 -1,5 dB

Capture Ratio:  1,0 dB

Selectivity:  80 dB

Spurious Rejection:  75 dB

Image Rejection:  60 dB at 98 MHz

Subcarrier Rejection:  60 dB

IF Rejection:  90 dB

AM Suppression:  50 dB

Muting Threshold:  13,3 dBf (2,5 µV)

Stereo Separation:

45 dB at 1,000 Hz

30 dB from 30 to 15,000 Hz

Antenna

300  balanced twin-line feeder

75   unbalanced coaxial cable

AM Tuner Section

Sensitivity:  300 µV/m (IHF, ferrite antenna)

Selectivity:  35 dB

Signal-to-Noise Ratio:  50 dB

Image Rejection:  35 dB

IF Rejection:  30 dB

General

Power Requirements:  AC 120 V, 60 Hz

Power Consumption:  220 W (2,7 A)

Dimensions (W x H x D):  480 x 115 x 390 mm (18,9" x 4,5" x 15,4")

Weight:  12 kg (26,4 lbs)


 

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