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





Sherwood S-7900A

 Here are sherwood's most advanced receivers. Unparalleled command enters for the finest high fidelity music systems. Featured are Sherwood's permanently aligned Ceramic FM IF filtering system, hermetically sealed microcircuits and Field Effect transistors to capture clear, distortion-free FM with utmost reliability. Built-in Dynaquad 4-channel matrixing circuit gives you thrilling four-dimensional sound at the touch of a finger. Choose AM/FM stereo or FM stereo only. Both offer the same outstanding features and quality.

Enjoy the operating ease provided by seven push buttons that control the main or remote stereo speakers for operation independently or together (at the flick of a rear panel switch, these pushbuttons activate front and rear speakers for your Dynaquad 4-channel system); Loudness contour; narrow band FM "Hush" circuit; high filter; tape monitor; and 4-channel decoder  (which doubles as a second Tape Monitor). Additionally Sherwood's unique front-panel tape jack (plus rear panel tape jacks) provide simultaneous recording on two recorders or dubbing from one recorder to another. Stereo headphone jack, too, for private listening. A large, illuminated zero-center tuning meter pin points FM turning to perfection.
 Sherwood FM reception is legendary, thanks to four-gang tuning capacitor, pre-aligned Ceramic IF filters, microcircuits, and the synchro-phase FM limiter/detector that provide pace-setting alternate-channel selectivity (65 dB), outstanding capture ratio (1,9 dB) and Am rejection (over 60 dB). Field-effect transistors in RF and mixer stages enable -95 dB spurious response rejection. With less than 0,15% FM distortion, Sherwood's clarity of sound is unsurpassed.

Power to spare! With 60 +60 watts RMS, 8 ohms from 20 to 20,000 Hz at 0,3% total harmonic distortion, these Sherwood receivers can drive two sets of stereo speakers plus mono extension speakers without strain. Direct-coupled output with Electronic Relay Protection circuit combine widest power bandwidth with maximum protection for your speakers.

Utilizing all-silicon transistors, Sherwood receivers achieve a reliability of performance backed by a full 3-year warranty on all parts. And Sherwood packages this superlative performance in a distinctively-styled, easy to operate receiver that fits in any decor. Whatever your wants-power, performance, beauty - Sherwwod paces the field.
 Special Features FM Tuner
Four gang tuning capacitor
Solid-State Ceramic FM IF Filtering
FET RF and mixer stages
Hermetically-sealed Micro-circuit IF and Synchrophase FM Limiter?Detector
Flywheel-assisted velvet tuning
Dial scale 7 ¾ inches long, 0,2 MHz calibrations
Exclusive FET FM Inter-channel/side-band hush
Illuminated Zero-center tuning meter
Illuminated dial pointer
Noise-protected automatic FM Stereo/Mono switching at 8 µV
Triple-section AM tuner (S-7900A only)
Specifications
FM Tuner Section
FM Sensitivity (IHF):  1,7 µV (-30 dB noise&dist)
Signal-to-Noise Ratio:  -70 dB
Capture Ratio:  1,9 dB
Suppression of AM:  -60 dB
Tuning Range:  87,5 to 108,5 MHz
Distortion:  0,15% at 100% Mod.
Spurious Response Rejection:  -95 dB
Stability:  ±15 kHz (±0.015%)
Image Rejection:  -80 dB
IF Rejection:  -90 dB
Alternate Channel Selectivity:  65 dB
Stereo Separation:  40 dB at 1 kHz
Frequency Response [Stereo/Mono]:  20 - 15,000 Hz / 20 - 20,000 Hz  ±1 dB
Antenna:  300 Ω balanced or 75 Ω unbalanced
AM Tuner Section
Sensitivity:  4 µV at 30% mod. For 10 dB S/N
Selectivity:  36 dB (at ±10 kHz)
Frequency Response:  4,0 kHz (at 4,0 kHz)
Tuning Range:  530 to 1625 kHz
Image Rejection:  -80 dB at 1MHz
Antenna: Ferrite Rod (rotatable), High Imp. Input

Amplifier Section
Power Output (IHF):  280 watts total
Power Output-RMS (both channel driven)
At 4 Ω : Music Power 90 Watts (1 kHz)
At 8 Ω : Music Power 65 Watts (1 kHz)
At 8 Ω : Music Power 60 Watts (20 - 20,000 Hz)
Harmonic Distortion:  0,3% at 8 Ω Rated Output, 0,10% at  10 watts
Intermodulation Distortion:  0,3 % at 8 Ω Rated Output, 0,10% at 10 watts
Stereo & Mono Speaker Output Impedance:  4, 8 or 16 Ω
Stereo Headphone Output:  High or Low Impedance
Stereo Recording Output:  800 mV, 2 k Ω
Power Bandwidth:  7 - 60,000 Hz  0,5% Dist.
Frequency Response:
Aux:  20 Hz - 20 kHz  ±1 dB
Phono :  RIAA Standard  ±1,5 dB
Damping Factor:  30 : 1 at 8 Ω
Bass Control:  ±13 dB at 100 Hz
Treble Control:  ±13 dB at 10 kHz
Input Sensitivity (for rated output):
Phono : 1,5 mV;  3,8 mV;  8,0 mV
AUX : 150 mV
Input Capability for 1 % Dist:
Phono : 100 mV
AUX : 2,5 V
Hum and Noise (IHF):
Phono : -65 dB
AUX : -80 dB
Vol. Control Min> : -90 dB
Crosstalk:  -40 dB at 1 kHz

General
Power Requirements:  115 - 125 V, 50/60 Hz, 10 to 100 W fused
AC Outlets:  100 W switched
Dimensions (W x H x D):  16¼ x 5¼ x 14 inches
Weight (Shipping):  30 lbs

Optional Walnut Case:  W-10 (17 x 14 x 6¼ inches)

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