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





Onkyo TA-200




Specifications
Type:  2-head, single compact cassette deck
Track System:  4-track, 2-channel stereo
Tape Speed:  4.8 cm/s
Heads:  1 x Record/Playback, 1 x Erase
Motor:  DC servo motor
Tape Type:  Normal, CrO2, Metal
Noise Reduction: HX-Pro, B, C
Frequency Response:  20 Hz to 17,000 Hz  (Metal tape)
Signal to Noise Ratio:  78 dB  (with Dolby C)
Wow and Flutter:  0.07%
Sensitivity:
Line Input:  60 mV
Line Output:  0.5 V
Power Requirements:  AC 220 V 50 Hz ; 22 W
Dimensions (W x H x D): 435 x 122 x 264 mm

Weight:  3.9kg

Advent 2

 Advent 2
If your budgett for stereo equipment is limited, and you would like the highest possible quality for what you spend, we believe a stereo system built around the Advent/2 loudspeaker may well be the best buy you can make.
We make that statment out of a conviction that the Advent/2 is a genuinely new kind of low-cost loudspeaker. Its sound quality is very close to that of the best speakers available at any price. It can fill a big living room with more than enough low-distortion sound to satisfy most people's greatest demands. And the bargain it represents is further increased by its efficiency, which is high enough to provide satisfying performance in average use with low-cost, low-power amplifiers and receivers.
The Advent/2 is the product of many years' experience in the design of speakers intended to offer better and better performance at lower and lower cost. Its overall design is based on evertything we have learned about talking the most simple and direct route to high performance, and we have put everything we can into it - including far more expensive basic loudspeaker components than ever before used in a system of its cost. Because it is intended to be first-quality in every sense, we have given as much attention to its appearance as to its performance, replacing the usual low-cost imitation wood cabinet with a distinctive  molded enclosure that we believe will look fresh and appealing for years to come.
The Advent/2 represents our best effort to provide absolutely eveything we believe important in a speaker for the lowest possible cost - and to bring genuine component stereo of very high quality to many people who otherwise might have to settle for something that only looks like the real thing.


Kenwood KR-9400


Kenwood KR-9400 AM/FM Stereo Receiver
Thr Kenwood KR-9400 stands as one of the truly great stereo receivers of the world, meeting the demands of th emost critical purist with the power, performance, and flexibility usually found only in the most expensive of separate components. The KR-9400 is the culmination of years of research and development on the part of Kenwood's engineering team, who have designed this very special unit with but one purpose in mind; to achieve the highest possible performance, regardless of cost.

A masterpiece of engineering with features never before incorporated in a stereo receiver.
Unique Kenwood Triple-Function Meter converts from Signal Strength Meter to Multipath detector to Deviation Meter at the touch of a button.
New Tape-Through Circuit permits tape-to-tape dubbing while you listen to another program source
New kenwood Injection Circuit mixes sound from any source into tape-to-tape dubbing
Triple Tone Controls provide full Bass, Treble, and Mid-range tonal compensation, with Defeat Switch for completely flat response.
Phase-Lock-Loop MPX Circuit; delivers exceptional FM-stereo separation for vivid directionality
Dolby FM Switch ; provides for the addition of a Dolby FM Adapter for best reception of Dolbyized FM broadcasts.

The Tuner Section
Famous the world over for the exceptional performance of its tuners, Kenwood outdoes its own reputation with the superb performance of the AM,FM and FM-stereo tuner section of the KR -9400
The FM Front End. To achieve the theoretical limit in FM sensitivity (1,7 µV), the KR-9400 incorporates an insulated dual-gate MOS-FET, combined with four separate tuned circuits. The extremely linear input of the r.f. stage is virtually impervious to cross-modulation and other forms of overload distortion.
The FM-IM Section. The high alternate channel selectivity (*) dB) and the remarkable capture ratio (1,3 dB) of the KR-9400 are the direct result of the permanently aligned solid state i.f. filter, a multi-function IC and five bi-polar transistors in the i.f. stage.
The Phase-Lock Loop Stereo Multiplex Decoder Section.
The kR-9400 provides extremely high FM-stereo separation throughtout the audio spectrum, thanks to the newly  developed phase-lock-loop IC circuit incorporated in the stereo FM decoder section, achieving more than 45 dB separation at 1 kHz; better than 35 dB at all frequencies from 30 Hz to 10 kHz.

The amplifier Section
The KR-9400 is the most powerful stereo receiver Kenwood has ever built, delivering a minimum of 120 watts of contiuous power per channel into 8 ohms speakers, both channels driven, 20 Hz to 20 kHz, with no  more thn 0,1% Total Harmonic Distortion
Direct-Coupled, Pure Complementary Symmetry Output Circuit
Kenwood;s advanced engineering eliminates the coupling capacitor between  output and speakers, so no distorting element stands  between you and the music. As a result you enjoy flat frequency response from ultra-lows to highest highs, a high damping factor (50 at 8 ohms), faithful bass response throughout the audio spectrum.
Large Power Transformer, Oversize Heat Sinks. A cool-running power transformer and massive heat sinks form the heart of a dual positive-negative power supply to the high-output transitors stages. This nocompromise design assures safe, cool operation even under continuous full-power output.
ASO protection Circuit. Kenwood 's "Area of Safe Operation" protection circuit will not interrupt your listening as long as the KR-9400 is operating within safe limits.shopuld those limits be exceeded, however, the sensitive electronic circuit with relay instantly disengages speakerrs.
Unique " Tape-Through" Circuit. The double tape monitoring facilities of the KR-9400 permit recording simultaneously onto two tape decks or dubbing from ona deck to the other. A unique "Tape-Through" cicruit carries recording convenience a step further by permitting the dubbing process to continue uninterrupted, even while the KR-9400 is being used to play another program source. Its's like owing two stereo systems in one.
The Preamplifier Section
The precision  equalizer-phono preamplifier section of the KR-9400 uses low-noise metal-encapsulated transistors to deliver an exceptionally high Signal-to-Noise ratio and assure utmost circuit reliability. Up to 300 mV (P-P) of input signal can be accomodated at less than 0,1% total harmonic distrotion, from a mere 2,5 mV phono input sensitivity.

Specifications
FM Tuner Section
Usable Sensitivity (IHF):  1,7 µV
Quieting Slope ( at 5 µV / 10 µV / 50 µV):  56 dB / 63 dB/ 72 dB
Signal-to-Noise Ratio:  72 dB
Capture Ratio (IHF):  1,3 dB
Selectivity Alt. Ch (IHF):  80 dB
Stereo Separation ( at 1 kHz / 10 kHz):  45 dB / 35 dB
Total Harmonic Distortion:
Mono :  0,3%
Stereo :  0,5%
Image Rejection Ratio:  80 dB
IF RejectionRatio:  100 dB
Harmonic Spurious Rejection:  90 dB
AM Suppression:  55 dB
Sub-Carrier Suppression:  62 dB
Antenna Impedance:  300 Ω balanced; 75 Ω unbalanced
AM Tuner Section
Uasble Sensitivity (IHF):  15 µV
Signal-to-Noise Ratio:   50 dB
Selectivity (IHF):  35 dB
Image Rejection Ratio:  70 dB
IF Rejection Ratio:  70 dB
Main Amplifier Section
Power Output: 120 watts per channel
Intermodulation Distortion:  0,1%
Preamplifier Section
Input Sensitivity/Impedance
Phono 1 and 2:  2,5 mV / 50 k Ω
Aux, Tape Play A, B:  150 mV/50 k Ω
MIC :  2,5 mV / 50 k Ω
Hum and Noise
Phono 1 and 2 :  70 dB
Aux and Tape :  93 dB
Mic :  65 dB
Output Voltage/Impedance
Tape Rec A, B
PIN :  150 mV/ 100 Ω
DIN :  30 mV/80 k Ω
Tone Controls
Bass :  ±10 dB at 100 Hz
Midrange :  ±10 dB at 800 Hz
Treble :  ±10 dB at 10 kHz
Loudness
At 100 Hz :  8 dB
At 10 kHz :  5 dB
Filters
High Filter:  12 dB/oct turnover 7 kHz
Low Filter:  12 dB/oct turnover 100 Hz
Power Requirements:  110/120 V 50/60 Hz
Power Consumption:  415 watts at full power; 60 watts at no signal
Dimensions (W x H x D):  21-15/16" x 6-9/16" x 15-9/16"
Weight:  45,4 lbs

Pioneer SA-5200


Pioneer SA-5200 - A compact, value-priced stereo integrated amplifier with advanced solid state circuitry and top versatility.

In the medium power and price range, few stereo amplifiers can match Pioneer's  SA-5200 for value and versatility. Designed for the person who is building his first set of home stereo components, this solid state amplifier offers the very latest circuit technology distinguished by superior stability and versatility. From the equalizer section to the power amplifier stages, the SA-5200 offers improved circuit design. The equalizer is unmatched in this price range for its precise RIAA equalization within +_0,5 dB as well as its ability for handling large inputs. In the power amplifier section, Pioneer has chosen complementary SEPP (Single-Ended, Push-Pull) ciruit with silicon transistors, offering ghigh efficiency and low distortion while delivering 13 watts + 13 watts of continuous power, both channel driven at 1 kHz into 8 ohms. The outstanding sound character of the SA-5200 makes it a value and a half, and the extent of this value is more than apparent when you price this amplifier. Another dynamic difference in true hi-fi components from Pioneer.

Circuit Description
Equalizer Amp
The signal from the Phono input terminal is fed to the input terminals of the equalizer amplifier stage, which employs a two-stage direct coupled circuit.
Since sufficient negative feedback from the second-stage collector is fed to the first-stage emitter, characteristics accurate to within ±0,5 dB on the RIAA curve can be provided. Compared with previous two-stage direct coupled circuits, this system makes for greater stability in the bass range and provides a surplus dynamic margin.
The amplified signal from the second-stage collector is fed to switch circuit-A ass'y through the Function Switch.

Control Amp
The signal selected by the Function switch is fed to the control amplifier through the Tape Monitor switch in switch circuit-A ass'y the loudness compensator circuit in switch circuit-B ass'y, and a potentiometer. The Tone Control circuit employs the nominal CR type configuration, and is connected after the one-stage amplifier. As in the bass and Theble tone controls, click-stop volume controls are employed, which provide high accuracy for flat frequency characteristics at the middle point of control knobs. The output of the control amplifier is fed directly to the power amplifier.

Power Amp
The power amplifier stage consists of seven transistors for each channel. It is composed of the thruout direct coupled  circuit with differential amplifier.
The signal from the control amplifier ass'y is fed to one base in the differential amplifier. The AC and DC negative feedabck from the output junction is fed to another base in the diffecrential amplifier so that overall stability is improved.
The differential amplifier output connects directly with the pre-driver base and amplifier. The signal from the pre-driver is amplifies by the driver and the power output stage, and fes to the speaker terminals through the Speaker switch in switch circuit-A ass'y.
Temperature compensation in the power amp ass'y is accomplished by a three-element varistor and the idle current adjustment by a semi-fixed variable resistor connected in series to the varistor.
Power transistor protection is accomplished by the fuse installed in series at the B-power circuit.

Power Supply
A full-wave rectifier circuits aupply all DC power. The rectified DC, with the ripple component eliminated by means of a 4,700 µF capacitor, is supplied for the output circuitry of the power amplifier circuit, and through CR filters for the other stages. The muting circuit eliminates the unpleasant noise usually heard when the power switch is turned On or Off. When the power switch is turned ON, the first-stage transitor Q1 in the power supply circuit is cut off immediately by the reverse bias caused  by a diode associated with the base.
When the power switch is turned OFF, the negative bias which has kept the first-stage transistor cut off is turned over to positive bias, and current entering the driver-stage transistor makes the second-stage transitor base connect to ground, the transitor cuts off the bias current entering the driver stage in the power amplifier ass'y. thus the amplifier stops working and unpleassant noise is eliminated.
A diode connected between the base and the emitter of the second-stage transistor permits discharge of the current charge in the power amplifier ass'y when the second-stage transistor is cut Off (when the power switch is turend Off).


 Specifications
Power Amplifier Section
Circuitry:  1st Stage Differential Amplifier, Dirct Coupled Quasi-complementary
 Continuous Power Output (both channel driven at 1 kHz):
15 W + 15 W at 4 Ω
13 W + 13 W at 8 Ω
Continuous Power Output (each channel driven at 1 kHz):
20 W / 20 W at 4 Ω
16 W / 16 W at 8 Ω
Power Output in 20-20,000 Hz (both channel driven):
10 W + 10 W at 8 Ω
Total Harmonic Distortion:
At continuous  Power  Output :  less than 0,8%
At 1 W + 1 W Power Output :  less than 0,2%
Intermodulation Distortion:
At Continuous  Power  Output :  less than 0,8%
At 1 W + 1 W Power Output :  less than 0,4%
Power Bandwidth (both channel driven IHF):  10 Hz - 40 kHz (THD 0,8%)
Output Speaker:  A, B, A+B (4 - 16 Ω)
Output Headphones:  4 - 16 Ω
Damping Factor:  more than 30 (1khz, 8 Ω)
 Preamplifier Section
Circuitry
Equalizer-amplifier:  2-stage Direct Coupled NFB type
Control-amplifier:  CR type
Frequency Response:
Phono (RIAA equalization):  30 Hz - 15 kHz ±0,5 dB
Tuner, Aux 1, 2; Tape Monitor :  15 Hz - 30 kHz ±1 dB
Hum and Noise (IHF, Shsort-circuited, A-Network):
Phono :  more than 70 dB
Tuner, Aux 1,2; Tape Monitor :  more than 90 dB
Input Sensitivity/Impedance:
Phono Mag :  2,5 mV/50 k Ω
Phono Overload Level :  100 mV/280 mV (rms/p-p)
Tape Monitor:  150 mV / 100 k Ω
Tape Rec/Pb (DIN  connector):  150 mV/100 k Ω
Aux 1, 2  :  150 mV/100 k Ω
Tuner :  150 mV/100 k Ω
Output Level/Impedance:
Tape Rec :  150 mV
Tape Rec/Pb (DIN connector)  30 mV/80 k Ω
Bass Control:  +12 dB; -10 dB at 100 Hz
Treble Control:  +9,5 dB; -10,5 dB at 10 kHz
Loudness Contour (-40 dB position):  +10 dB at 100 Hz ; +6 dB at 10 kHz
Power Requirements;  AC 120 V 60 Hz or AC 110 V , 120 V, 130 V, 220 V and 240 V 50/60 Hz (switchable)
Power Consumption:  85 W max
AC Outlets:  1 Switched, 1 Unswitched
Semiconductors:  22 Transitors; 7 Diodes
Dimensions (W x H x D):  415 x 132 x 328 mm (16-5/16" x 5-3/16" x 12-15/16")
Weight:  7,2 kg (15 lb 13 oz)

Harman/Kardon Citation Eleven

 Harman/Kardon Citation Eleven
Professional Solid State Stereophonic Preamplifier/Audio Equalizer

When Harman/Kardon introduced the Citation  A preamplifier  several years ago, it represented  a major breakthrough in solid state design. Within a short period of time, it became the audiophile's standard of excellence. In fact, the "A" is still recognized today by many audio authorities as the finest stereo preamplifier ever designed.
With the introduction of the Citation Eleven, Harman/Kardon has once again innovated a major change in the design and function of high performance solid state stereo preamplifiers.
The Citation Eleven uses the potential of transistors more completely and creatively than any other preamplifier in existance. It is a computer-crafted instrument that easily meets or exceeds every performance parameter ever established for a preamplifier. The simple truth is that the Citation Eleven is the best stereo preamplifier ever made.
 Total Flexibility and Control Over Acoustics
An important new design concept has been incorporated into the Citation Eleven to make it the most versatile stereo preamplifier ever created for home use. H/K engineers have determined that standard tone controls, even professional switched types, limit flexibility for they do not permit precise adjustment of program material over the entire audio range.
The Citation Eleven employs a professional type audio equalizer which gives the user complete control over program material, room acoustic and deficiencies within the speakers. Operating at predetermined hinge points, the audio equalizer adds or deletes audio energy to any of five points within the audio spectrum to compensate for inaccuracies in program material or within the playback system. It is no longer required to match room acoustic to the speakers by re-positioning furniture or by adding draperies and rugs to the room. The Citation audio equalizer controls room acoustics by permitting the user to set the five controls to suit his own personal requirements. Hot spots, ear-piercing high, frequency response drop out, excessive bass and even mid-frequency harshness can now be cancelled out by adding or deleting audio energy at the specific points in the audio spectrum where these probllems occur.

Below: another version of H/K Citation Eleven
 Listening quality of the Citation Eleven is superb , and not easily described in terms of laboratory measurements. The preamplifier offers solidity combined with an openness that sets it apart from all others. The more you listen to the Eleven , the more you become aware of the great achievement it represents. Anyone who wants the very best and will not be satified with anything less than the finest, will be well-advised to see and hear the new Citation Eleven.
Specifications
Audio Output:  up to 6 volts RMS into 10 k ohms
Frequency Response:  below 5 Hz to beyond 125 kHz ±0,5 dB
Square Wave Rise Time:  less than 1 ms at 20,000 Hz
Square Wave Tilt:  less than 5% at 20 Hz
Total Harmonic Distortion:  less than 0,05% at 6 volts RMS from 10 to 30,000 Hz
Below residual level of most test instrumentation at 2 volts RMS and below
Intermodulation Distortion:  less than 0,05% at the equivalent 6 volts RMS output
Noise (Unweighted):
Low Level :  65 dB below 6 volts at 10 mV input reference
High Level:  80 dB below 6 volts  ( volume control wide open)
Residual:  900 dB below 6 volts
Sensitivity:
Low Level :  1,5 mV for 2 V output
High Level :  150 mV for 2 V output ( in all auxiliary positions except Aux 3, which is 300 mV for 2 V output)
High Cut Filter:  -8 dB at 10,000 Hz, 6 dB /octave slope
Subsonic Filter:  -12 dB at 15 Hz, 6 dB/octave slope
Input Impedance:
Phono :  47  k Ω
Aux :  20 k Ω
Output Impedance:
Source Impedance :  less than 500 Ω
Recommended Load :  10, 00 Ω or greater
Phono Overload:  Greater than 115 mV
Audio Equalizers:  Five sliding controls operaating at the following hinge points; 60, 320, 1k, 5 k, 12k Hz. Boost and cut ±12 dB, each position
Phono Equalization:  RIAA curve ±0,5 dB
A.C. Convenience Receptacles:  Three switched. One unswitched
On/Off Switch:  Pushbutton, heavy duty rating
Function Selector:  Mag. Phono 1, Mag. Phono 2, four high level positions
Mode Selector:  Stereo, Stereo Reverse, Mono, LeftChannel only, Right Channel only
Balance Control:  Zero to infinity type
Volume Control:  Close tracking dual potentiometers, frequency insenstive within range of frequency response specifications
Speaker Selector:  Permits choice of speaker system 1, system 2 or both at once when preamplifier is connected in the manner described in the instruction manual
Headphone Receptacles:  Two low impedance headphone receptacles controlled by front panel speaker selector switch. May be switched in or out at user's discretion.
Output Receptacles:  Four main preamplifier outputs. Four outputs for tape recording
Inputs:
Two pair for low level phonograph
Four pair for high level equipment
Two pair for tape monitor
Two grounding termnals
Power Requirements:  117 volt, 50/60 Hz or 220 volt operation, AC line fuse
Dimensions (WxHxD):  16-1/16" x 4-3/4" x 12"
Weight:  20 pounds

TEAC C-2


Teac's Stereo Cassette Deck - Advanced Technology Delivers Professional Sound


The C-2 stereo cassette recorder has been precision-engineered to give you top-quality performance. Two motors and a solidly built transport give improved tape-to-head contact eliminating dropouts, plus an extremely low wow and flutter figure. A 3-head design produces superior frequency response, resulting in clear, beliavable sound reproduction. Switch-selectable bias and equalization allow optimum performance from any type of tape, and in addition allows you to take advantage of the new metal particle tape which provides greatly enhanced reproduction fidelity.

Features
True 3-Head System
3-Position Bias/EQ for All Popular Tapes
Two Motor/Feather Touch Micro-Switched Full Logic Controlled Transport
dbx II Interface ( Optional)
Differential Gear-Coupled Record Level Controls
Record Mute
Optional Plug-in Bias/EQ Modules to Optimize Performance
Remote Control Capability
Dual-Process Dolby Noise Reduction System
Peak Program Meter
Programmable Timer Function
Standard Rack Mount
Optional Accessories
RC-90 Remote Control
RX-8 dbx Unit
TO-8 test Tone oscillator to Set Bias precisely
CX-8B Adjustable Bias/EQ Card (Brown)

Specifications:
Track System:  4-Track, 2-Channel Stereo
Motors:
1 x FG Servo-Controlled DC Capstan Motor
1 x DC Reel Motor
Heads:  3 ( Erase, Record and Playback)
Type of Tape:  Compact Cassette C-60, C-90
Tape Speed:  1-7/8 ips
Wow and Flutter:  0,05% (NAB Weighted)
Frequency Response: 
Metal Particle Tape :  20 - 20,000 Hz
Co (CrO₂) Tape :  20 - 18,000 Hz
Low Noise Tape :  20 - 16,000 Hz
Signal-to-Noise Ratio:  58 dB (can be improved with Dolby NR) to 63 dB/ 1 kHz, 68 dB / over 5 kHz
Fast Forward/Rewind Time:  90 seconds for C-60
Inputs:
2 x Line :  60 mV/30 k Ω
2 x Mic :  0,25 mV (-72 dB)/200 Ω or more
Outputs:
2 x Line :  0,3 V/50 kohm or more
1 x Stereo Headphone Jack / 8 Ω
Power Requirements/Consumption:  117 V AC, 60 Hz / 33 W
Dimensions (W x H x D):  482 x 147 x 345 mm 919" x 5-3/4" x 13-1/2")
Weight:  14 kg (31 lbs)