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

Akai GXC-570D

Experience the utmost in operating ease and capability with this "top of the line" cassette deck.
This prestige tape deck is designed for the ultimate in convenience and recording and playback quality. Incorporates the world's most advanced engineering techniques, mechanisms, and parts including Akai's GX Head, 3 Motor double capstan drive system.
 GX 3 Head, 3 Motor, Double Capstan Drive System.
The GXC-570D is Akai's top front loading type cassette tape deck and, naturally employs Akai's renown wear-free GX recording and playback heads. Further, a new head arrangement assures perfect tracking so that clumsy azimuth alignment mechanism, beacons, etc. are completely unnecessary.
With this unique 3 head system, the recording and playback heads are mounted in a single head holder. This arrangement provides perfect parallelism of recording and playback head gaps and, because of the proximity of the heads, there is no phase deviation between recording and playback head tracks. Azimuth loss is also eliminated so that azimuth alignment, etc. is unnecessary. This new head positioning plus the professional characteristics of the GX heads themselves brings out the full capability of the tape. Also head-to-tap conect is improved and ideal head shielding reduces feed through of magnetic flux.

A new C.P.G. type AC Servo Motor and two completely new DC "slotless" rotor core motors constitute the superior drive system of this model. The AC Servo capstan drive motor is a C.P.G. (Center Pole Frequency Generated) motor with which a center magnetic pole is established for equal radiation. Merits of this motor include greater inertia and increased output for an extremely quiet motor with perfectly accurate motor revolutions. For reel drive, the GXC-570D employs two of Akai's brand new "slotless" DC drive motors. Because the core of this motor is cylindrical (has no concave or convex parts), there is no variation between the magnetic poles of the magnetic field. Thus, there is no torque unevenness. These unique features result in smooth motor rotation for the elimination of motor rotating noise and decreased woa and flutter.
Closed loop double capstan drive.
One each capstan and pinch roller positioned in parallel on either side of the head block provides perfectly stable tape tension and tape speed. This system shuts out the adverse influence from outside the "closed area" between capstans so that there is no tape vibration. This together withthe 3 motor drive system, extra large flywheels, and a specially designed head mounting plate with linear ball bearing mechanism assures complete stability, perfect head-to-tape contact, and reduces wow and flutter to 0,08% WRMS. So drop-out at recording time is also minimized.

Use low Noise, Chromium Dioxide, or ferri-Chrome Tape.
A 3-way Tape Selector Switch sets the machine to ideal bias and equalization according tothe tape being used. The ability to use quality tape compements the superior mechanism of this machine for the optimum in recording and playback quality.

Repeat playback plus memory Rewind.
When the repeat Button is depressed, at the end of playback or recording mode, the tape rewinds and the machine is automatically set to continuous playback mode. The Memory Rewind Button can be used together with the Index Counter and set to effect stop mode from rewind at any place on the tape. Memory Rewind can also be used together withthe Repeat Button for automatically setting the machine to continuous playback mode from memory rewind position.

Fast Forward and Rewind Speed Control.
Adjust Fast forward and Rewind time according to tape thickness. Prevents thin tape from being broken at high speed.

Pitch Control Playback
Modify playback musical tone as desired with Pitch Control adjustment. Musical interval can be changed by up to plus/minus 1 semi-tone (tape speed plus/minus 5%). Also convenient for precise adjustment of tape speed when playing back tapes recorded on another machine.

Double process Dolby And A-B Monitoring.
This machine incorporates the Double Dolby process system wherein low level signala are raised prior to recording and lowered proportionately at playback time. With this process, extraneous noise is eliminated, also eliminating tape hiss. The GXC-570D's 3 head system and Tape Monitor Switch facilitates A-B monitoring, and the Double Dolby process extends this feature to Dolby recording as well. Further, because there is no space between the recording and playback heads, ther is no time lag between recorded and played back signals during monitoring. Thus, truly professional results are attained.

Other Important Features:
Precise Recording Calibration
Akai's  A.D.R. (Automatic Distortion Reduction) System
Meter Selector Sets Meters for VU Meter or Peak Meter Indicator
Sound Mixing form Separate Sources
Smoothe Logic Circuit Operating Controls Feature Direct Function Change
Limiter Switch Cuts Distortion for Clear Recording at Close Range
Front Loading Convenience
MPX Filter Switch
Automatic Tape Setting Prevents Tape Slack and Assures Stable Tape Start
Double Action Oil Damped Cassette Eject
Instantaneous Full Release Automatic Stop
Automatic Door Opener

Pause Control and Output Level Control

Track System:  4-track, 2-channel stereo system
Tape:  Compact Cassette Type
Tape Speed:  1-7/8 ips (pitch control playback ±5%)
Wow and Flutter:  less than 0,06% WRMS (less than 0,17% DIN 45500)
Frequency Response: 
30 Hz to 15 kHz (±3 dB) :  using low noise tape
30 Hz to 16 kHz (±3 dB) :  using CrO₂ tape
30 Hz to 19 kHz (±3 dB) :  using Fe-Cr tape
Distortion:  less than 1% (1,000 Hz "0" VU) using low noise tape
Signal-to-Noise Ratio:  better than 52 dB
Erase Ratio:  better than 70 dB
Bias Frequency:  100 kHz
Heads:  GX recording head; GX playback  head; GX erase head
One  - AC Servo outer-rotor motor for capstan drive,
Two  - DC motors for reel drive
Fast Forward/Rewind Time:  60 to 80 seconds (variable) using a C-60 Cassette tape
Output Jacks: 
Line :  0,775 V ("0" VU)/ more than 20 k Ω
Phone :  50 mV/ 8 Ω
Input Jacks:
Microphone :  0,3 mV/ 600 Ω
Line :  70 mV/ 100 k Ω
Semiconductors:  110 Transistors; 159 Diodes; 12 FETs; 9 ICs
Power requirement:  110 V to 240 V, 50/60 Hz (switchable)
Dimensions (W x H x D):  440 x 255 x 255 mm )17,3" x 10,0" x 8,9")
Weight:  13,5 kg (28,5 lbs)
Optional  Accessories:  RC-17 or RC-18 Remote Control

Tannoy SRM 10B

 10" Dual Concentric Drive Unit
Calibrated High Frequency Controls
Time Compensated with Syncsource™ for Unipoint Accuracy
Compact Monitor

The monitor shall be a compact type, with an internal volume of 35 litres. The cabinet shall contain a single 10" drive unit of a Dual Concentric design, incorporating a passive delay network to give a phase better than ±25° over the frequency band 100 Hz to 10 kHz.
The monitor shall have an anechoic sensitivity of 90 dB, measured across its full frequency band width of 55 Hz - 20 kHz, ±4 dB.
The monitor shall be suitable for use with amplifiers rated up to 150 W per channel and shall be capable of handling peak inputsof 250 W.
The monitor shall be a Tannoy SRM 10B.

Drive Units - The drive units in the SRM Series, while being of three different frame sizes (10", 12",and 15"), are all Dual Concentric Loudspeakers. A horn-loaded compression driver handling the high frequencies is mounted within a direct radiator bass unit on the same frame.
Bass Unit - this is a low resonance speaker with  a 2" high temperature voice coil. The felted paper cone gives smooth performance extending well into the midrange region.
Treble Unit - high frequencies are reproduced by a 2" diameter aluminium voice coil and duralumin diaphragm, horn loaded through a phase compensating multiple throat. The flare of the HF horn is continued by the LF cone.
The crossover network divides the signal from the amplifier betwen the high and low frequency drives. To avoid degradation of the audio signal Tannoy SRM Series crossovers use only the finest quality components, rigidly mounted on a glass fibre reinforced printed circuit board.
Generously rated resistors and inductors, and low loss solid dielectric capacitors are all capable of withstanding the high peak powers associated with modern wide dynamic range recordings. Complex switching circuitry, with two controls enable loudspeaker responses to be tailored to the listening environment.
To provide optimum performance a loudspeaker cabinet must be of very rigid construction. eachSRM Series cabinet is constructed of high density particle board, lined with acoustic foam to absorb reflections and eliminate standing waves. Bitumen material damps mechanical resonances, while any spurious resonances which can occur in large panel areas are eliminated by rigid internal crossbracing.
The exposed surfaces of each cabinet are veneered in American Walnut, hand rubbed with oil and wax to enhance the natural richness of the wood. The finishing touch to each loudspeaker is given by the detachable grilles covered in an attractive, acoustically transparent cloth.
Low frequency loading of each loudspeaker is provided by a carefully designed ducted port system, which reduces distortion and extends bass response.
Recommended Amplifier Power:  10 - 150 W (RMS per channel)
Peak Power Handling:  250 W
Impedance [Nominal/Minimal]:  8 Ω / 5,5 Ω
Sensitivity (2,83 V at 1 m):
Domestic :  93 dB
Anechoic :  90 dB
Frequency Response:  55 Hz - 20 kHz (±4 dB)
Phase Response:  better than ±25° between 100 Hz to 10 kHz
Apparent Acoustic Source:  169 mm behind front surface of baffle
Dispersion at -6 dB points:  90° conical at 10 kHz
Crossover Frequency:  1,2 kHz
Crossover Type:  Overdamped second order low pass coupled with first order high pass filters.  Parallel impedance compensation together with SyncSource second order all pass passive delay network. Positive acoustic palarity 5 position treble energy attenuator and 4 position roll off slope.
Internal Volume:  35 litres
Cabinet Material:  18 mm high density particle board and internal damping material
Cabinet Finish:  Real walnut Veneer
Grille:  Single piece - brown fleck cloth on wooden frame
Cabinet Dimensions (H x W x D):  524 x 350 x 265 mm (20½" x 15" x 13½")
Cabinet Weight:  18 kg (40 lbs)

JBL 4301B

 JBL 4301B   2-way Broadcast Monitor, this smallest monitor is designed primarily for the broadvast control room and edit booth, and has achieved wide acceptance in home studios, remote recording and quality controlareas. Smooth, wide range response and low distortion are obtained from 200 mm (8 ") low frequency and 36 mm (1,4") high frequency loudspeakers. A high frequency level control is provided on the front baffle. Available in oiled walnut with dark blue grille.
The 4301B shares its basic performance characteristics with all other JBL monitors - exceptional clarity, wide dynamic range, solid bass and open high frequency reproduction. The 4301B is efficient enough to produce a sound pressure level of 98 dB in a typical broadcast booth of 1,8 m x 3,0 m x 2,4 m with an amplifier delivering only 10 watts rms. The compact enclosure of the 4301B is designed to fit the smaller spaces typical of broadcast control booths, production studios or mobile recording , broadcast and film editing facilities.

Frequency Dividing Network
Smooth control of the component loudspeakers is achieved by a frequency dividing network engineered and tested to complement the electrical and acoustical character istics of the system. The dividing network is fitted with a continuosly variable control that permits adjusting the relative level of the high frequency direct radiator to suit listening preferences and room conditions. The control does not affect the crossover frequency, not does it limit the upper frequency response of the loudspeaker system. 
 High Frequency Direct Radiator
The open, crisp treble performance of the 4301B is the product of a 36 mm (1,4") direct radiator designed for clarity, smoothness of response and power handling capacity the 16 mm (5/8") copper voice coil is large in relation to cone size for efficiency and transient reproduction with definition and accuracy, yet the diameter of the cone and center dome has been kept small to obtain wide dispersion. The magnetic assembly weighs 0,74 kg and generates a flux density of 1,5 tesla.
The 4301B utilizes a low frequency loudspeaker specifically engineered for a compact enclosure without the compromises usually associated with smaller drivers. The 200 mm (8") loudspeaker exhibits unusually smooth frequency response, wide dynamic range, superior transient reproduction and low distortion for a unit of compact size. It features a precision die-cast aluminum frame for structural integity under the most severe operating conditions. The 50 mm (2:) diameter copper voice coil is suspended in a magnetic  field having a flux density of 0,85 tesla. The magnetic field is generated by a 1,28 kg (3 lb) low-loss magnetic assembly. Mass and compliance of the integrally stiffened cone have been carefully selected to optimize low frequency bandwidth and definition while reducing distortion. As with all JBL loudspeakers, this unit provides maximum power handling capacity and efficiency consistent with the bandwidth expected of the device.

Size and configuration of the 4301B enclosure have been carefully matched to the acoustic characteristics of the component loudspeakers as well as the intended use of the complete system. To achieve maximum strength and resistance to vibration, all enclosure joints are hand fitted; all panels are constructed of 19 mm dense compressed stock. Acoustic damping material is applied to the interior surfaces of the side and back panels to attenuate standing waves within the enclosure. A ducted port extending through the baffle panel provides proper acoustical loading of the low frequency loudspeaker. All components mount directly to the baffle panel and are removable from the front of thr enclosure. The four side panels are veneered with solid American black walnut, hand rubbed to a rich, lustrous finish enhancing the natural beauty of individual grain structure and color.
Frequency Response:  45 Hz - 15 kHz (±3 dB)
Power Capacity:  15 W (Continuous Sine Wave)
Nominal Impedance: 8 Ω
Power Output:  88 dB SPL (measured at 3 m in a room volume of 57 m³ with an average absorption of 18,6 m² at ½ rated power input , -3 dB)
Sensitivity (1 W at 1 m):  88 dB SPL
Distortion (½ Power, 87 dB SPL/3 m. single Frequency):  0,5% or less third harmonic generation from 100 to 15,000 Hz
Crossover Frequencies:  2,5 kHz
Polar Response:  no less than -6 dB at 90° horizontal and vertical to 10 kHz
Enclosure Volume:  30 litres
Dimensions (H x W x D):  483 x 292 x 306 mm (19" x 11½" x 12")

Weight (net):  12,7 kg (28 lbs)

Sansui 771

FM/AM Stereo Receiver
You enjoy greater stereo power and superior stereo performance at much less cost with Sansui's newest medium-priced FM/AM stereo receiver, the 771. thanks to its refined CBM (Circuit Board Module) construction, the 771 outperforms many higher-priced receivers in the field. Here's how.

Thanks to CBM, which simplifies construction, reduces costs and increasas electronic capabilities, the moderately-priced 771 is able to offer a very superior power amplifier - an all-stage direct-coupled OCL powerhouse delivering a continuous RMS 40W/40W (total music power of 140 watts) to drive up to two stereo pairs of speakers at a time with less than 0,5% THD and a urprisingly wide power bandwidth of 15 to 40,000 Hz. Its FM/AM tuner features an MOS FET equipped FM section with sensitivity of 2,0 µV (IHF) to pull in the fuzziest of stereo signals with surprising clarity. And its preamplifier and control sections are equally outstanding providing inputs and controls for two stereo tape decks, two Aux, a microphone circuit, a superior 2-stage direct-coupled phono equalizer, distortion-free tone controls with FETs, audio muting, low/high filters and loudness, and a unique stereo/mono switch which bypasses the FM multiplex circuit when it is turned to mono position.
 Exclusive Sansui CBM design improves performance while reducing costs.
Sansui developed the unoque CBM technique specifically for its finest 2- and 4-channel studio and consumer products. This new design concept increases electronic capability and dependability, reduces wiring and size, and greatly lowers the expense of construction and chassis assembly. The 771 incorporates four such CBM units, one each for its tuner, preamplifier, power amplifier and power supply sections. Ordinary receivers with considerably higher price tags require up to a dozen complicated and potentially troublesome circuit boards to produce the same results.
 Sensitive FM tuner with integrated circuits and MOS FETs
The RF amplifier in the 771's newly-designed FM frontend uses a dual-gated low-noise MOS FET and a 4-gang tuning capacitor to pull in distant or weak signals with high resolution while rejecting undesired interference from stronger adjacent stations. The F amplifier and FM mixer stages are coupled through a double tuning circuit to achieve excellent selectivity, intermodulation and image characteristics. Outstanding FM sensitivity is 2,0 µV (IHF). The FM IF section incorporates three bi-resonator ceramic filters, a sharply-limiting 2-stage 2-IC differential amplifier and a phase-compensation circuit for greater phase linearity. The sum effect of these devices is reflected in the receiver's excellent FM capture. AM suppression and S/N ratios and its low THD performance.

Newly-developed IC-equipped FM Multiplex demodulator.
The 771's new FM multiplex demodulator features a high-density IC for improved stability. Stereo separation is better than 35 dB and THD in stereo FM reception is less than 0,6%. An FM de-emphasis switch inside the chassis allows the 771 to be easily converted for ideal reception of FM signals anywhere in the world.
Wide-Range, whine-free AM tuner.
Like the FM section, the circuitry of the 771's superior Am tuner is designed for the sharp, clean reception and reproduction of both local and distant signals. It features a 2-gang tuning capacitor, and a bi-resonator Jaumann type ceramic filter to eliminate AM whine and other annoying noise. The built-in AM ferrite bar antenna is space wound and highly sensitive.
 Dependable, independent amplification power.
An all-stage direct-coupled OCL semi-complementary power amplifier is employed in the 771 to provide dependable and extemely clean stereo power to drive even the largest of stereo speaker systems with ease. Thanks to a differential amplifier in its initial stage and its dual plus/minus power supply, independent from the supply stages in other parts of the receiver, you have at your command a full 40 watts of continuous RMS power per channel (into 8 ohms at 1 kHz, both channels driven). Its power bandwidth is especially wide - from 15 to 40,000 Hz -  while THD and IM Distortion figures are both held to a low, 0,5% or below at any power level up to the rated power output. This means that you can enjoy clear-cut high-fidelity reproduction of a broad audio spectrum from the rich and mellow bass tones to tingling and transparent highs.

Other Features:
Easy-to-read linear tuning scale and smooth-tune mechanism.
Direct-coupled low-noise phon equalizer.
Microphone circuit for extra convenience.
NF type tone control amplifier with FETs.
Two tape record/playback circuits and two stereo Auxiliary inputs.
Power protection a plenty.
Attractive champaigne-gold front panel with user-oriented control display.
All-wood cabinet with cushioned no-mar feet.
Audio Section
Power Output (at rated distortion)
Music Power (IHF) : 140 W (4Ω, 1kHz);  110 W (8Ω, 1kHz)
Continuous Power
Each Channel Driven : 55/55 W (4Ω, 1kHz);  45/45 W (8Ω, 1kHz)
Both Channels Driven : 40 + 40 W (8Ω, 1kHz);  32 + 32 W (8Ω, 20-20,000Hz)
Total Harmonic Distortion (at rated power output):
Overall (fromAUX) : less than 0,5%
Intermodulation Distortion (at rated power output, 70Hz : 7,000Hz = 4 : 1 SMPTE method)
Overall (from AUX) : less than 0,5%
Power Bandwidth (IHF):  15 to 40,000 Hz
Frequency Response (at 1 Watt power output)
Overall (from AUX) : 15 to 30,000 Hz,  +1  -2 dB
Equalization (at tape Rec output):  RIAA Curve (30 to 15,000 Hz ±1 dB)
Load Impedance:  4 to 16 Ω
Damping Factor:  60 (8Ω)
Channel Separation (1kHz at rated power output)
Phono : better than 45 dB
Aux 1, 2 : better than 45 dB
Hum and Noise (IHF)
Phono : better than 70 dB
Aux 1, 2 : better than 80 dB
Input Sensitivity and Impedance (1kHz for rated poer output)
Phono : 2,5 mV/ 50 kΩ (Max. Input capability 200 mV at rated distortion)
Mic (monophonic) :  2,5 mV/50 k Ω
Aux 1, 2 : 100mV/50 kΩ
Play Pin Jacks : 100 mV/50 kΩ
Rec/Play DIN Socket : 100 mV/50 kΩ
Tape-2 (4-ch adaptor)
Play Pin jacks : 100 mV/50 kΩ
Recording Output
Rec Pin Jacks : 100 mV
Rec/Play DIN Socket : 30 mV
Tape-2 (4-ch adaptor)
Rec Pin Jacks : 100 mV
Switches and Controls
Bass : +12 dB, -12 dB at 50 Hz
Treble : +12 dB, -12 dB at 10,000 Hz
Loudness : +10 dB at 50 Hz;  +8 dB at 10,000 Hz
High Filter : -10 dB at 10,000 Hz (6 dB/oct)
Low Filter :  -10 dB at 50 Hz (6 dB/oct)
Tuner Section
FM Mode
Tuning Range:  88 to 108 MHz
Sensitivity (IHF):  2,0µV
Total Harmonic Distortion
Mono : 0,4%
Stereo : 0,6%
Signal-to-Noise Ratio:  better than 60 dB
Selectivity:  better than 60 dB
Capture Ratio:  2,0 dB
Image Rejection:  better than 70 dB at 98 MHz
IF Rejection:  better than 90 dB at 98 MHz
Supurous Response Rejection:  better than 80 dB at 98 MHz
Spurious Radiation:  les than 34 dB
Stereo Separation:  better than 35 dB at 400 Hz
Frequency Response:  30 to 12,000 Hz;  +1 -3 dN
Antenna Input Impedance:  300Ω balanced (75Ω unbalanced)
AM Mode
Tuning Range:  535 to 1,605 kHz
Sensitivity (Bar Antenna):  50 dB/m at 1kHz
Selectivity:  better than 28 dB at 1MHz
Image Frequency Rejection:  better than 80 dB/m at 1Mhz
IF rejection:  better than 80 dB/m at 1MHz
Semiconductors:  49 Transistors;  25 Diodes;  3 FETs;  3 ICs;  4 Zener Diodes
Power Requirements
Voltage : 100,117, 220, 240 V  50/60 Hz
Consumption : 100 W (rated), 310 VA (max.)
Dimensions (W x H x D):  480 x 135 x 300 mm (18-7/8" x 5-3/8" x 11-13/16")

Weight:  12 kg (26,4 lbs ) Net;  14,6 kg (32,7 lbs) Packed

Luxman L-31

 The L-31 was designed to seek the best cost performance and to attain simplicity yet retaining the necessary features for true Hi-Fi from the view-point of practical use after an exhaustive review of current amplifiers in terms of both circuit and function.

Meticulous care is paied to the visual appearance and design to yield an image of high class audio component. An aluminium extruded front panelof light gold is housed in the massive wooden case in perfect harmony with metal and moulded knobs, whereas an attractive escutcheon is placed at the tone-control and lever switches. Needless to say the result of human engineering is taken into account and all the controls are arranged for the easiest operation.
The basic power amplifier section employs complete direct-coupled DC output amplifier circuitry with differential driving utilizing dual rail power supply to ensure a large damping factor down to the ultra low frequency range for driving the loudspeakers efficiently.
The output stage consists of by now mandatory pure complementary circuit with combination of PNp and NPN transistors. Thus crossover distortion is kept extremely low, while high reliability is realized by means of TO-3 transistors with good heat-dissipation. At the same time the transistors of high cut-off frequency at the driver stages suppress distortion in the treble range. The biggest problem in the pre-amplifier section lies in noise, which was solved by using ultra low noise transistors and resistors in addition to low leakage electolytic capacitors.

The equalizer stage is composed by 2-step direct coupled amplifier of PNp and NPN transistors, which ensures excellent linearity and sufficient phono overload voltage of 150 mV 91 kHz, RMS, phono).
Independent tone-control of the well-known Lux exclusive NF type is provided for both right and left channels, whose mechanical centre point offers a true flat frequency response.

The overall harmonic distortion at the pre- and main-amplifier is no more than 0,05% and I.M. distortion is also no more than ,01%. While the S/N ratioat phone exceeds 64 dB.
The annexed accessories imperative for daily use are provided such as tape monitor circuit, DIN tape connector, speaker selector, etc.
Power Output RMS:  38 W/38 w (8 Ω, both channel driven)
Total Harmonic Distortion:  no more than 0,05%
I.M. Distortion:  no more than ,01%
Power Bandwidth:  10 -50,000 Hz (-3 dB less than 0,1%)
Frequency Response:  15 - 50,000 Hz (-1 dB)
Input Sensitivity:
Phono :  2,6 mV
Tuner, Aux 1, 2 :  150 mV
Input Impedance:
Phono ;  50 k Ω
Tuner, Aux 1, 2 :  more than 60 k Ω
Signal-to-Noise Ratio:
Phono :  more than 64 dB
Tuner, Aux1, 2 :  more than 83 dB
Monitor :  more than 83 dB
Residual Noise:  -87 dB
Tone Control:  lux type NF tone Control
High Cut :  7 kHz - 6 dB/oct
Low Cut :  70 Hz - 6 dB/oct
Damping Factor:  more than 90 dB (8 Ω)
Semiconductors:  27 transistors; 8 Diodes; 2 Zener Diodes; 1 LED
Power Supply:  110-120, 220-140 V 50/60 Hz
Power Consumption:  170 W (8 Ω, max output, both channel driven);  150 W (CSA, UL rated)
Dimensions (W x H x D):  440 x 160 x 225 mm (17-3/8" x 6-5/16" x 8-7/8")

Weight:  7 kg (15,4 lbs) net

Sony TAN-8550

 Stereo Power Amplifier. Prestige main amplifier with revolutionary V-FETs.

Power output of 100 W + 100 W RMS from 20 Hz to 20 kHz, both channels driven, at 8 ohms and under 0,1% THD.
Newly developed P-channel and N-channel V-FETs in a true complementary triple push-pull circuit which is coupled directly to the speaker terminals for faithful signals.
Dual FETs in triple differential circuit of Class-A amplification stage - for stable performance regardless of temperature fluctuation as well as for high input impedance.
Optical peak program meter - extremely quick response to show accurately the amount of power being fed to the speakers. Two-position sensitivity switch of X 1 (from 0 to 200 W) and X ¹/₁₀ (from 0 to 20 W).
Chimney type heat-sink provides effective cooling for stable performance.

Speaker Level Control
An independent level control is provided with B-speaker circuit (convenient to test or balance two different systems or to compensate for a difference in speaker efficiency)
Subsonic Filter
Prevents sound from adversely affecting by inaudible low frequency components, such as those generated by rumble or acoustic fedback in a turntable system (Normal/test switch on the rear panel).
 Sony power V-FET (Vertical Field Effect Transistor)
V-FET has ideal characteristics for an audio amplifier:
Quick transient response to pulsive signals, which assures minimum distortion and excellent phase response.
High input impedance and low output impedance, which allows excellent circuit design with greater flexibility and ease.
Smooth pinch-off characteristics which assures miniumu distortion.
Voltage controlled input characteristics which cause virtually no partial current concentration, assuring temperature stability.
Continuous Power Output RMS (both channels driven at 8 Ω, 0,1% THD):
100 W + 100 W :  20 Hz to 20 kHz
110 W + 110 W :  1 kHz
Power Bandwidth  (IHF):  5 Hz - 50 kHz
Harmonic Distortion:
At rated output :  0,1%
At 1 W output :  0,05%
I.M. Distortion (60 Hz : 7 kHz = 4:1):
At rated output :  0,1%
At 1 W output :  0,05%
Frequency Response: 
20 Hz - 100 kHz  +0 -3 dB (Normal)
DC - 100 kHz  +0 -1 dB (Test)
Residual Noise:  0,01 µW
Signal-to-Noise Ratio:  100 dB (closed circuit)
Inputs Sensitivity/Impedance:  1 V (for rated output)/ 50 k Ω
Output:  Speaker A,B and Direct
Power requirements:  AC 100, 120, 220 or 240 V  50/60 Hz
AC Outlet:  Unswitched 200 W
Dimensions (W x H x D):  440 x 170 x 410 mm (17-3/8" x 6-3/4" x 16-1/8")

Weight:  19 kg (41 lb 14 oz)

Sony TAE-8450

 Stereo  Unexcelled Preamplifier with virtually unmeasurable distortion Sony TAE-8450.

Sony has utilized important advances in audio trchnology, the finest materials and meticulous craftsmanship to to construct the  TAE-8450  - a preamplifier which satisfies demands for the highest quality in a home music systemm, or a professional sound reinforcement system. From an engineering standpoint, the TAE-8450's design and circuitry are innovative, yet highly refined. From a listening and operating standpoint, the engineering breakthroughs mean the highest degree of sonic fidelity and the simplest, most precise means of control.  An operating test should reveal even more, such as the unit's excellent transient and phase response, which can be fully appreciated when musical signals are heard.

Optical peak Reading meter.
The TAE-8450 is equipped with an elaborate, professional metering system, providing visual readings of the actual peak value of complex musical signals for both left and right channels. Until now, this type of metering system has been used only in the most modern hi-fi systems.
 Circuitry and performance Highlights.
The TAE-8450's measurable specifications, such as frequency response, signal-to-noise ratios and distortion levels, are all excellent. Transient and phase response, measurable under laboratory conditions, but perhaps more meaningfully evaluated under musical conditions, are also excellent. Sony's new direct coupled DC amplifiers, with highly stable FET differential circuitry, are used as unit amps and as buffer amps, assuring consistently good response to complex waveforms at all frequencies. These newly designed amplifiers are used for phono equalization, flat amplification and for tone control. The unit amplifier consists of an N-channel FET differential circuit, coupled directly to a PNP transistor differential circuit. The output from the PNP circuit is then connected directly to a buffer amplifier. This arrangement brings critical performance factors close to the theoretical ideal. Highinput impedance and low output impedance are realized, along with ultra low distortion levels. Both harmonic and IM distortion  are practically nonexistent, measuring 0,03% and 0,05% respectively, at the rated output level of 1 volt. And they are only 0,1% at an output level of 14 volts. In fact, distortionis so low that the residual distortion of measuring instruments themselves often interferes with making an absolutely accurate aeasurement. Wide frequency response, as well as superior transient and phase response, are also assured by the advanced new circuitry.
 Frequency response curves for high level inputs are ruler flat from 10 Hz to 100 kHz, while phono equalization is also unusually impressive, corresponding to the RIAA  curve ±0,2 dB. Such precise equalization is obtained by using  an independent amplifier unit with negative feedback for turnover below 1 kHz, and another amp unit plus a shut RC filter to rolloff above 1 kHz. In addition, phono inputs are directly coupled to the equalizing amp, providing faithful response over a wide dynamic range, and excellent transient and phase response with any phono cartridge used.
The comprehensive phono input system also allows two turntables to be hooked up simultaneously, and the front panel selector permits easy switching. Each input  has a sensitivity selector switch for a 1,5 mV input and a 4,5 mV input. In addition, the phono 2 input has a booster position for extra low level cartridges (0,16 mV). Termination impedance for phono 2 can also be selected - 50 k Ω or 100 k Ω for 1,5 mV or 4,5 mV, and 10, 30, 100 or 1,000 ohms for the 0,16 mV position.  S/N ratios are high for all phono inputlevels: 75 dB with an input sensitivity of 4,5 mV, 70 dB for 1,5 mV, and 60 dB for phono "low", with an input sensitivity of only .16 mV. The last figure is achieved with the use of new, low noise NPN type transistor, designed specially for ultra low signals. This front stage transistor is coupled directly to two Darlington connected PNP transistors, assuring  a  good signal-to-noise ratio while obtaining necessary gain. The need for an external step-up transformer is thus eliminated. There is also ample headroom above the rated input level; 400 mV for the 4,5 mV input, 140 mV for the 1,5 mV input, and 13 mV for the.16 mV input.
Differential FET amplifiers.
Dual optical peak level meter.
5 semifixed input level controls.
Phono sensitivity and impedance selector.
Special booster amplifier for extra low level output cartridges.
Direct coupled FET differentioalamplifiers and buffer amps in equalizer and tone control stages.
Direct coupled phono input circuit.
Tape monitoring for 2 recorders and independent tape dubbing switch.
Professional attenuator type volume control with switch for 20 dB instant muting.
Highlight Features
Unexcelled performance characteristics, including superior transient and phase response.
Optical peak reading level meter.
Comprehensive control and connection facilities for exceptional operating flexibility.
Peak program Meter 9at PEAK mode):
Frequency Response:  30 Hz - 30,000 Hz  +0 -3 dB
Response Range:  -50 dB — +5 dB (0 dB =1 V RMS), with the Meter Sens switch pulled … -30 dB — +25 dB
Response Time:  1 millisecond at PEAK mode

Frequency Response:
Phono 1, 2  :  RIAA equalization curve ±0,2 dB
Mic, Tuner :  20 Hz - 20 kHz +0 -3 dB
Aux 1, 2, 3 :  10 Hz - 100 kHz +0 -1 dB
Tape 1, 2 :  10 Hz - 100 kHz +0 -1 dB
Ext Adat. :  10 Hz - 100 kHz +0 -1 dB
Tone Controls (11 steps, each 2 dB):
Bass   :  ±10 dB at 50 Hz (Turnover  frequency at 250 Hz)
Bass   :  ±10 dB at 100 Hz (Turnover frequency at 500 Hz)
Treble  :  ±10 dB at 10 kHz (Turnover frequency 2,5 kHz)
Treble  :  ±10 dB at 20 kHz (Turnover frequency 5 kHz)
Low :  12 dB/octave below 10 Hz or 40 Hz
High :  12 dB/octave above 9 kHz or 20 kHz
Resence Control:  +3,5 dB at 1 kHz
Residual Noise:  less than 70 µV (with Volume set fully counterclockwise, Tone to mechanical-mid position, Filters to Off, presence to Off)
Harmonic Distortion:  less than 0,03% at rated output, 1 kHz
IM Distortion (60 Hz : 7 kHz = 4:1):  less than 0,05% at rated output
Power Requirements:  100, 120, 220, 240 V AC, 50/60 Hz
Power Consumption:  22 W
AC Outles:  2 switched 400 watts, 1 unswitched 400 watts
Dimensions (W x H x D):  440 x 170 x 340 mm (17-3/8" x 6-3/4" x 13-3/8")

Weight:  11,8 kg (26 lbs) , net

Dual C 819

 We shall be pleased to send you the complete Hirsch-Houck report if you write to us  directly. If you'd rather not wait, here are some additional key excerpts:
" in its price class, the Dual 819 has some formidable competitors, and one has the right to expect first-class performance from any cassette deck selling for more than $400. nevertheless, even in such distinguished company, the 819 stands out."
"… the extremely low flutter, flat frequency response and low noise level of the 819 , combined with its superbly accurate and useful meters, make this one of the more attractive values ina high-quality cassette deck. Such features as the fade/edit system and the bidirectional memory can be considered simply as bonuses."
"The Maxell UD-XL-I tape provided a very flat record-playback response (at -20 dB) within ±0,75 dB from 30 to 15,000 Hz …. The response with Sony Ferrichrome was flat within ±1 dB from 33 to 15,000 Hz … the Dolby tracking was among the best we have measured … with a weighted RMS reading the flutter was an amazing 0,035%. It is clear that in all aspects of its design and performance, the Dual 819 is a first-class unit."

One final comment of our own. As you know, Dual's reputation for quality, precision and reliability has been based upon the performance of our turntables. When we introduced our first cassette decks, we knew they must establish a reputation of their own. And it is evident that they are doing just that.
The precision DC motor is fitted with an integrated frequency generator and modern control IC for speed regulation. The Dual decoupling motor suspension provides propagation of vibration and running noises.  A precision made flat belt drives the capstan and thereby plays its parts in the overall excellence of the wow and flutter characteristics. The tape take-up torque receiver its drive via a second belt direct from the motor so that disturbances such as differences in cassette winding have no effect on the tape transport.
For the fast wind facility a functionally reliable gear drive is used. This guarantees trouble-free winding even for older cassettes.
A photo-transistor continuosly monitors tape movement and prevents formation of loops in the tape. At the same time it also provides the signals for auto stop. This function is independent of the cassette or tape switching foil.
Careful tape location and precise azimuth setting ensure optimum treble reproduction and prevent level fluctuation.
The amplifier is functionally designed and constructed with plug-in modules for easy accessibility. In spite of the complexity of the equipment all the components are readily accessible.  The expense occured in achieving this, in comparasion with other models in this price category, will be of no interest to the service technican but you will find it satisfying to know that if a repair should ever be necessary every thought has been given to this being effected quickly and at minimum cost.
Tape Speed:  4,75 cm/s
Deviation from Correct Speed:  less than ±1%
Fast Winding Time:  below than 65 sec for C-60 cassette
Frequency Response:
Fe Tape :  20 - 15,000 Hz
CrO₂ Tape :  20 - 16,000 Hz
FeCr Tape :  20 - 16,000 Hz
Signal-to-Noise Ratio [with Dolby/without Dolby] (weighted):
Fe Tape :  better than 64 dB /  57 dB
CrO₂ Tape :  better than 64 dB /  57 dB
FeCr Tape :  better than 67 dB /  61 dB
Wow and Flutter: 
RMS weighted :  less than ±0,07%
To DIN for Reproduction Only :  less than ±0,10%
To DIN for Recording/Reproduction :  less than ±0,14%
Harmonic Distortion:
Fe Tape :  less than 1,0%
CrO₂ Tape :  less than 2,8%
FeCr Tape :  less than 1,5%
Channel Separation at 1 kHz:
Between Stereo Channels :  better than 40 dB
In Opposite Direction :  better than 70 dB
Erasure:  better than 70 dB (1 kHz)
Oscillator (Push/Pull oscillator):  100 kHz
Input Sensitivity/Impedance:
Microphone :  0,26 mV/2 k Ω
DIN connector :  0,50 mV/6,3 k Ω
RCA jacks :  40 mV/580 k Ω
Overload Capacity of Inputs:
DIN Connector :  40 dB
Mic Connector :  50 dB
Output Level/impedance (adjustable):
DIN connector :  0 -580 mV/ 5,5 k Ω
RCA jacks :  0 - 580 mV/2,0 k Ω
Tape Monitor (Photo-electric shut-off time):  less than 0,6 sec
Headphone Impedance:  4 - 2000 Ω
Semiconductors:  6 ICs;  39 transistor; 27 Diodes, 2 LEDs
Power requirement:  110 - 125 V, 220 - 240 V; 50/60 Hz
Power Consumption:  16 watts
Dimensions (W x H x D):  438 x 148 x 360 mm

Weight:  6,5 kg