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





JVC JR-S400 receiver


FM/AM Stereo Receiver with S.E.A. Graphic Equalizer
Though in size and looks it's the same as the higher-power JVC model, the JR-S400 has slightly less output power and a correspondingly lower price. Its solidly-built OCL power amplifier section delivers a comfortable 70 watts per channel, min. RMS, into 8 ohms, both channels driven, over a 20 Hz to 20 kHz range, with no more than 0,2% Total Harmonic Distortion. It has virtually the same fine FM?AM section and S.E.A. Graphic Equaliser as the JR-S600, though, and two Phono, two Tape and FM/AM/AUX source selection as well as two-system speaker selection and more.

Power Section
Good transient response and ample power reserve are assured with the pure complementary OCL power amp section, with an initial differential amp followed by a Class A predriver leading to a Darlington-connected parallel push-pull final stage.
Power Supply
A well-regulated transformer improves power response during high-amplitude musical passages, while reducing distortion and crosstalk in the subsonics. No power reserve dry-up is possible thanks to dual huge capacitors. JVC's patented Triple Power protection circuit is included.

Phono Equalizer
The PNP-NPN-PNP phono equalizer accepts up to 200 mV input with negligible distortion. The RIAA curve deviation is ±0,5 dB.

FM and AM Highlights
As in the JR-S600, the tuning capacitor in this precision FM section is the 4-gang, frequency linear type affording, in combination with a low-noise FET, greatly increased FM sensitivity. The up-tilted, super-long (200 mm) FM/AM dial high-inertia dual-flywheel design, a unique lateral-tune control and stretch-free "Radial Cord" cables in the tuning mechanism mean quick, dependable operation. Also as in the more expensive JR-S600, the FM selectivity is increased without harm to other specifications or sound quality by the use of a new 4-resonator single-unit ceramic filter, coupled with a 4-ploe phase-linear LC filter, in the FM IF section.

Other features:
Consstant-Voltage Dual Power Supply
Slider Controls - volume and balance
Push-button source selectors
Two-deck recording/dubbing - Monitor and record to both; dub (copy) from Deck1 to Deck2
FM Muting Off/Mono switch
Loudness High and Low filters
FM Det out Jack
One-touch / 2-system speaker terminals
Internal FM antenna switch
Pre-out
Two AC outlets and more

Specifications
Output Power: 
70 watts per channel, min. RMS, at 8 Ω from 20Hz-20kHz, with no more than 0,2% T.H.D.
80 W per channel into 8 Ω (1 kHz T.H.D. 0,2%)
100 W per channel into 4 Ω (1 kHz, T.H.D. 0,2%)
Intermodulation Distortion:  0,3% at rated output
Damping Factor:  50 at 8 ohms
Load Impedance:
4 - 16 Ω per System 1 or 2
8 - 16 Ω per System 1 +2
Input Sensitivity/ Impedance:
Phono :  2,5 mV (50 k Ω)
Aux :  220 mV (70 k Ω)
Tape Play (PIN, DIN) :  220 mV (70 k Ω)
Signal-to-Noise ratio (IHF Short-Circuit A network):
Phono :  70 dB
Aux :  95 dB
Tape :  95 dB
Recording Output:
PIN :  180 mV
DIN :  30 mV ( 80 k Ω)
Phono Equalizer Deviation:  ±0,5 dB from RIAA Curve
Phono Overload :  200 mV (RMS), 560 mV (p-p)
S.E.A. center Frequencies:  40, 250, 1 j, 5 k , 15 kHz
S.E.A. Control Range:  ±12 dB
FM Tuner Section
Usable Sensitivity:  9,8 dBf (1,7 µV/ 300 Ω)
50 dB Quieting Sensitivity:
Mono :  16 dBf (3,5 µV/300 Ω)
Stereo :  36,8 dBf (38 µV /300 Ω)
Stereo Separation (at REC Out): 
50 dB  at 1 kHz
35 dB at 10 kHz
Distortion [Mono / Stereo]:
100 Hz :  0,1% / 0,25%
1 kHz :  0,1% / 0,25%
6 kHz :  0,25% / 0,4%
Signal-to-Noise Ratio (Max. 1000 µV input):
Mono :  72 dB
Stereo :  65 dB
Alternate Channel Selectivity:  80 dB
Capture Ratio:  1 dB
Image response ratio:  100 dB at 98 MHz
AM Suppression:  55 dB
FM DET Output:  100 mv (10 k Ω)
AM Tuner Section
Sensitivity:
300 µV/m (bar antenna)
30 µV (ex, antenna)
Signal-to-Noise ratio:  55 dB
Dimensions (W x H x D):  560 x 169 x 431 mm (22-1/16" x 6-11/16" x 17")
Weight:  18,5 kg (40,8 lbs)



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