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





Hitachi SR-804

 Hitachi the new leader in audio technology introduces the world's most powerful 50 watt receiver.
The new SR-804 stereo reciver has the revolutionary Class G amp that instantly doubles its rated power from 50 to 100 watts to prevent clipping distortion during those demanding musical peaks (note the clipped and unclipped waves in the symbolic graph above).
The SR-804 is conservatively rated at 50 watts RMS, 20 - 20,000 Hz into 8 ohms with only 0,1% THD.
Class G is just one example of Hitachi's leadership in audio technology. Power MOS FET amplifiers, R&P 3-head system cassette decks, Uni-torque turntable motors, and gathered-edge metal cone speakers are just some of the others. Ther's a lot more. 
Specifications
Tuner Sections

FM Stereo Frequency Range:  88 -108 MHz
Usable Sensitivity (IHF): 
Mono : 10,3 dBf (1,8 µV)
Stereo : 20 dBf (5,5µV)
50 dB Quieting Sensitivity:
Mono : 17 dBf (3,9 µV)
Stereo : 37 dBf (39 µV)
Harmonic Distortion (at 65 dBf):
100 Hz : 0,2% (Mono);  0,3% (Stereo)
1 kHz : 0,15% (Mono);  0,25% (Stereo)
6 kHz : 0,25% (Mono);  0,3% (Stereo)
Signal-to-Noise Ratio:  74 dB (Mono);  68 dB (Stereo)
Frequency Response:  30 Hz - 12 kHz   +0,5 dB
Image Response Ratio:  90 MHz - 56 dB; 98 MHz - 50 dB; 106 MHz - 45 dB
Spurious Response Ratio:  80 dB
IF Response Ratio:  80 dB
Alternate Channel Selectivity:  75 dB
Capture Ratio:  1 dB
AM Suppression Ratio:  55 dB
Stereo Separation:  45 dB (1 kHz)
Sub Carrier Suppressions:  50 dB
SCA Rejection:  65 dB
Muting Thereshold:  20 dBf (5,5 µV)
Antenna Input:  300 Ω balanced
AM Section
Frequency Range:  530 - 1605 kHz
Sensitivity:  370 µV/m (S/N 20 dB), 20 µV (IHF ext. Antenna)
Selectivity (IHF):  36 dB
Image Rejection Ratio:  50 dB
IF Rejection Ratio:  42 dB
S/N Ratio:  50 dB
Antenna:  Ferrite antenna and separate terminal
Audio Section
Music Power (IHF):
60 W/ch + 60 W/ch (8 Ω, 1 kHz, 0,1% THD)
65 W/ch + 65 W/ch (4 Ω, 1 kHz, 0,1% THD)
RMS Power Output (both channel driven):  50 watts per channel, min. RMS, at 8 Ω from 20 - 20,000 Hz, with no mor than 0,1% THD
Frequency Characteristics:  10 Hz - 30 kHz (+0 -1 dB);  10 Hz - 40 kHz (+0 -2 dB)
Power bandwidth:  10 - 40,000 Hz (½ RMS Power, 0,1% THD)
Harmonic Distortion: 
At rated output : Less than 0,1%
At ½ rated output :  Less than 0,05%
Intermodulation Distortion:
At rated output : 0,1%
At ½ rated output : 0,05%
Tone Controls:
Bass : ±10 dB at 100 Hz
Treble : ±10 dB at 10 kHz

Power Source:  100V/120V/220V/240V  50/60 Hz

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