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





Yamaha R-700 receiver

Natural Sound AM/FM Stereo Receiver

Combining technology  and musical sensitivity

The R-700 is a direct development of Yamaha's unique design philosophy - an approach that aims first and foremost at achieving the very highest in music reproduction accuracy. In addition to electronic measurements, extensive subjective and comparative listening tests by teams of music specialist monitor overall progress toward our design goals as well as indicate which areas need to be focussed on in order to maximize audible improvement in performance. These uncompromising efforts have resulted in a number of significant design innovations, as well as many subtle refinements which are continually improving the reproduction quality of Yamaha audio products.

Every detail and feature that can possibly affect sound quality - even to the slightest degree - is given thorough consideration and testing to ensure that its incorporation in the product will result in a positive benefit in terms of sound quality. The exciting new Yamaha spatial expander control offered on the R-700, for example, lets you "spread" the stereo sound field beyond the limits imposed by speaker location to more accurately recreate the image of a live performance.

In short, our approach combines both scientific method and musical sensitivity, allowing us to apply our technology to those areas of each product where it will do the most good; where you con hear it.

Super-Stereo Spatial Expander

Advanced Yamaha technology overcomes the last barrier to true high-fidelity reproduction. The Spatial Expander puts "ambience" back in the reproduced sound - the one element that conventional stereo cannot provide. With normal stereo reproduction, the apparent locations of the various music instruments are limited to the space between the left and right stereo speakers. Many so-called "ambience enhancement" systems attempt to overcome this by adding an extra pair of speakers - naturally requiring an extra amplifier plus the separate ambience unit - thereby considerably increasing system cost and inconvenience. The Yamaha Spatial Expander control, however, offers continously variable expansion of the stereo sound image, putting a more realistic distance between the musicians and creating an incredibly "live" sound without the need for any extra speakers or amplification.

DC Configuration Power Amplifier Section

Like the rest of the R-700, its power amplifier section is specifically designed to amplify and transmit the music waveform to your speakers without adding distortion. In fact, the R-700's excellent 0,015% distortion figure is maintained even at full 50 watts per channel power output. This has been accomplished by using a direct-coupled power amplifier design that eliminates capacitors in the signal path so distortion caused by phase shift of the music signal is minimized. The result is that you hear the music - not the amplifier - exactly the way it was originally recorded.

Other features

Continuously Variable Loudness Control

Record any source while listening to any other

Subsonic and High filters

lowNoise Phono Equalizer

 

The Tuner a better design for better sound

Station Locked Synthesizer Tuning System Quartz PLL

Synthesizer tuners actually have built-in noise, distortion and interference. Their internal quartz oscillator and frequency dividers, although accurate, are generating radio frequency signals within the tuner itself so some interference due to leakage of these signals is virtually unavoidable.

Station Locked Syntesizer Tuning Systems ICs

The R-700 tuner section, on the other hand, uses Yamaha's unique StationLocked tuning system which,in addition to being extremely accurate because it locks the tuner's frequency directly onto that of the broadcast station, produces no interference causing RF noise. You get pinpoint tuning accuracy plus pure, distortion-free reception - precisely what a first-class tuner should provide.

Ultra-Linear Direct FM Detector

Another impressive Yamaha technological feature incorporated in the R-700 tuner section is the ultra-linear direct FM detector circuit. It features greatly improved linearity even when compared to the recent pulse-count detector designs, and a greatly simplified signal path ensures that no noise or distortion is added to the music signal. The is just one of the innovations incorporated in the R-700 tuner section that help to raise FM reception to the level where if can justifiably be called "high fidelity".

DC NFB PLL Multiplex Demodulator

The purpose of the multiplex demodulator is to separate the left and right chanels of the composite stereo signal. Most high-performance tuners nowadays use a method which involves turning the composite signal on and off at a 38 kHz rate. Because the switches used for this are in the signal path, however, switching distortion can be a problem. The multiplex demodulator of the R-700 solves this by incorporating high-speed switches into the NFB loop of a high-slew-rate DC amp., thereby throughly absorbing any trace of switching distortion. Overall, this circuit provides excellent stereo separation, low harmonic and intermodulation distortion, and superior transient response for the most natural FM stereo reproduction.

Other Tuner Features:

Sophisticated tuning convenience, like pushbutton search tuning, and 5 FM/5 AM station preset tuning.

Optimum reception in any conditions, with automatic DX/Local switching, Auto Blend, and signal quality meter.

 


Specifications

Audio Section

Minimum RMS Output Power per Channel:

50 W (17 dBW) , 8 , 20 - 20,000 Hz , 0,015% T.H.D.

55 W (17,4 dBW), 8 , 1 kHz, 0,01% T.H.D.

Dynamic Headroom (8 ):  2,5 dB

Total Harmonic Distortion (30 - 20,000 Hz)

Phono MM to Rec Out (3 V output) :  0,005%

Aux?Tape to SP Out (8 , 1 W):  0,005%

Intermodulation DIstortion Ratio

Aux/Tape to SP Out (8 , 25 W):  0,01%

Power Bandwidth (8 , 25 W, 0,02% T.H.D.) :  5 to 40,000 Hz

Damping Factor (8 , 1 kHz):  better than 40

Frequency Response (Aux/Tape to SP Out, 8 ):  5 - 1000,000 Hz -1 dB

RIAA Deviation Phono MM :  ±0,5 dv

Input Sensitivity/Impedance:

Phono MM :  2,5 mV/47 k  , 220 pF

Aux/Tape :  120 mV/47 k

Input Sensitivity (New IHF)

Phono MM :  0,35 mV

Aux/Tape :  17 mV

Max. Input Level (0,01% T.H.D.)

Phono MM (20 - 20,000 Hz ) :  200 mV

Phono MM (1 kHz) :  250 mV

Output Level/Impedance:

Rec Out :  120 mV/470

Headphone Output :  259 mW (0,015% T.H.D.)

Signal-to-Noise Ratio (IHF A network)

Phono MM (5 mV, input Shorted) :  85 dB

Aux/Tape (input Shorted) :  100 dB

Signal-to-Noise Ratio (new IHF)

Phono MM :  74 dB

Aux/Tape :  85 dB

Residual Noise (IHF  A Network) :  115 µV

Channel Separation (1 kHz, Vol -30 dB, 5.1 k )

Aux/Tape to Other Channel :  -53 dB

Phono MM to Other Channel :  -53 dB

Tone Control Characteristics

Bass (boost/cut) :  ±10 dB at 50 Hz

Treble (boost/cut) :  ±10 dB at 20 kHz

Turnover Frequencies

Bass :  350 Hz

Treble :  3,500 Hz

Filter Characteristics

Low (Subsonic, EQ Built-in):  15 Hz, -12 dB/oct

High :  8 kHz, -6 dB/oct

Continuous Loudness Control (Level-Related Equalization)

Max. Attenuation:  -20 dB at 1 kHz

Rec Output Level/Impedance (Fixed)

FM (100% mod. 1 kHz) :  500 mV/4,7 k

AM (30% mod. 1 kHz) :  150 mV/4,7 k

Tuner FM Section

Tuning Range:  87,6 to 108 MHz

50 dB Quieting Sensitivity

Mono (DX) :  3,2 µV (15,3 dBf)

Stereo (DX, Auto Blend) ;  25 µV (33,3 dBf)

Usable Sensitivity IHF Mono (1 kHz, 100% mod.)

300  :  2,5 µV (13,2 dBf)

75  :  1,25 µV (13,2 dBf)

Image Response Ratio (98 MHz):  62 dB

IF Response Ratio (98 MHz):  100 dB

Spurious Response Ratio (98 MHz):  100 dB

AM Suppresion Ratio (IHF):  65 dB

Capture Ratio:(IHF):  Local 1,5 dB; DX 2,2 dB

Alternate Channel Selectivity (IHF):  Local 30 dB; DX 82 dB

Selectivity (Two Signals):  DX 68 dB

Signal-to-Noise Ratio

Mono :  84 dB

Stereo :  80 dB

Distortion Mono

100 Hz :  Local 0,06%; DX 0,1%

1 kHz :  Local 0,06%; DX 0,3%

6 kh :  Local 0,08% DX 0,7%

Distortion Stereo

100 Hz :  Local 0,07%; DX 0,1%

1 kHz :  Local 0,07%; DX 0,5%

6 kh :  Local 0,09% DX 0,8%

Intermodulation DIstortion (IHF)

Mono :  Local 0,07%; DX 0,5%

Stereo :  Local 0,08%; DX 1%

Stereo Separation (Local)

50 Hz :  44 dB

1 kHz :  50 dB

10 kHz :  45 dB

Frequency Response

50 Hz to 10 kHz ±0,3 dB

30 Hz to 15 kHz ±0,5 dB

Subcarrier Product Ratio:  50 dB

Muting Threshold (DX):  5 µV (19,2 dBf)

Auto-DX Threshold:  30 µV (34,8 dBf)

Tuner AM Section

Tuning Range:  525 to 1,605 kHz

Usable Sensitivity (loop antenna):  200 µV

Selectivity:  30 dB

Signal-to-Noise Ratio:  50 dB

Image response Ratio:  40 dB

Spurious response ratio:  50 dB

Distortion (1 kHz):  0,3%

General

Semiconductors:  42 Transistors; 20 ICs; 3 FETs; 31 Diodes; 14 LEDs

Power Requirements:  110 - 120 V, 220 - 240 V 50/60 Hz

Power Consumption:  120 W

Dimensions (W x H x D):  480 x 122 x 337 mm (18-7/8" x 4-3/4" x 13-1/4")

Weigth:  9  kg (19 lbs 13 oz)

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