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





Tannoy System 15 DMT II

 HIGH PERFORMANCE REFERENCE MONITORING
 A main monitor system for Recording and Post-production studios where the requirement is for high performance, natural sound reproduction. With a single coherent wavefront thanks to the 15" Dual Concentric™ point source driver, sound presented to the engineers is remarkably distortion free. And with the enlarged monitoring position provided by this remarkable drivers wide dispersion, monitoring with the System 15 DMT II is particularly fatigue free.
 The availability of new materials and manufacturing processes has allowed Tannoy to design the System 15 DMT II from first principles, producing an all new Dual Concentric™ monitoring system with all the classic benefits of single point source monitoring combined with an exceptionally detailed but fatigue-free sound.
 The style of the cabinet is not arbitrary, it has been arrived at by considering the acoustic principles of diffraction and energy storage.
The trim rings around the rubber surrounds are there to smooth out the otherwise discontinuous contour to the HF wavefront.
The smooth lines around the port tubes ensure laminar air flow at low frequencies where the air in the ports has maximum velocity.
 The shapes of the LF cones continue the hyperbolic waveguide for the HF energy propagation.
The cabinet bracing and internalconstruction ensures that the HF unit can deliver the detail into the sound field.
The application of the Differential material Technology approach to component behaviour ubder vibration and magnetic fields has lead to custom crossover components, custom cabling and split crossovery design being employed.
Specifications
Frequency Response (±3dB, measured at 1m in anechoic chamber):  38 Hz – 25 kHz
Recommended Amplifier Power:  50 to 400 W rms into 8 Ω
Peak Power Handling:  600 watt
Power Handling:  Average:  200 W rms;  Programme: 400 W rms
Nominal Impedance:  8 Ω
Sensitivity (Averaged over specified bandwidth for half-space environment. For anechoic conditions the figure is to be decreased by 3dB):  101 dB SPL /2.83V at 1 m
Distortion:  Less than 0.5% (38 Hz - 25 kHz)
Dispersion (at -6dB):  90 conical
Crossover Frequency and Type:  1,1 kHz; 2nd order overdamped LF; 1st order HF Positive acoustic polarity
Crossover Controls:  Treble energy range 2 kHz -20 kHz (settings) +1,5 dB, Level, -1,5 dB
Drive Units:  15" full range, single Point Source, Dual Concentric™
Internal Volume:  100 litre
Low Frequency design:  Optimised bass-reflex loaded, in 140 litres
Cabinet Construction:  MDF (36mm - front and back; 20.6mm - top, bottom and sides) with energy absorbing bracing matrix and TF-2 acoustic wadding
Cabinet Finish:  Velti shadow grey soft-texture finish. High pressure twin laminate in shadow grey with metallic speckled finish on top, bottom and sides
Grille:  Single piece, black acoustically transparent material on a wood- en frame
Cabinet Dimensions (HxWxD):  840 mm x 550 mm x 440 mm (33” x 21.6” x 17.3”)

Cabinet Weight:  45kg (99.2lbs)

KRK Model 6000

 Audio Monitoring Systems. Close-Field Monitors
Extremaly smooth frequency response.
High power handling
Compact and portable
Low distortion
 Designed for close field monitoring applications, the diminutive KRK Model 6000 has inherited the sonic characteristics of the KRK Model 7000B, the industry standard compact monitor for top-of-console placement. The most competitively prieced close-field monitor to join the renowend KRK line, the 6000s utilize the latest in aerospace materials and the highest quality components. The monitor is also available in a video shielded version ,the  6000S.

 The components are comprised of a 6-inch polyglass woofer and a 1-inch Kevlar inverted dome-tweeter. The system is crossed over at 2,4 kHz with a passive crossover network. The KRK 6000 can handle up to75 continuous watts and has a maximum SPL of 106 dB, which is more than adeguate in near-field applications.
Perfect for all close-field applications, the KRK 6000s delivery an extremely smooth frequency response with very low distortion. Their small size and weight  of only 18 lbs, each make them extremely portable for independent engineers who like to move their own reference monitors from studio to studio.
Specifications
Drivers: 6" polyglass woofer; 1" kevlar tweeter
Frequency Response:  62 Hz to 20 kHz ±3 dB
Sensitivity:  89 dB (1 W at 1 m)
Max Power handling:  75 W
Max SPL:  106 dB
Crossover: Passive 2-way
Crossover Point:  2,4 kHz
Nominal Impedance:  8 Ω
Cabinet Finish: Custom Gray texture
Dimensions (W x H x D):  9" x 13" x 10"

Weight:    18 lbs net (36 lbs shipping)

McIntosh MX 113

 The McIntosh Tuner-Preamplifier unit concept accommodates all regular inputs of tuner, phono, tape, etc.,  and allows the selection of the right power amplifier needed for your system. The MX 113 is the most advanced version of this remarkable AM-FM/FM Stereo Tuner preamplifier with switchable selectivity. It has performance beyond any other manufacturer's equipment available today.

Special Features
Multiple "selectivity" switchable from the front panel. An elegant solution to a tough problem.
Linear Phase (constant delay) IF amplifier for low distortion at even high selectivity and low distortion.
Steggered tuning condenser elements to improve RF front and behavior, less interstage coulping, lower spurious effect, higher Q circuits.
Tremendous accomodiation of strong RF input signals - up to 10 volts without overload - overcoming an aggravating limitation of conventional tuners.
Highest spurious rejection 90 dB (IHF) and highest image rejection 95 dB (88 to 108 MHz). This means you receive the stations at the right place on the dial only. You don't receive the same stations or some mixture as you tune across the dial.
Ultra Sonic "muting" provides smooth inter channel FM noise suppression. Has complete connection to McIntosh Maximum performance Indicator to maximize your listening pleasure.
McIntosh developed a special detecting circuit used in the multiplex section. An advantage of this circuit is the elimination of the critical adjustments necessary with commonly used matrixing circuits. The circuit detects the L - R side-bands, then automatically matrixes the recovered information with the L + R carrier signal. This yialds the left and right program output with maximum separation.
 TUNING MECHANISM AND DIAL DRIVE
In the MX 113, the unique design and careful manufacture of the mechanical assembly gives smooth flywheel tuning. By controlling the relationship of mass and mechanical resistance, and by dividing the workloads in the dial drive system, it becomes nearly impossible to detect any backlash. Yet, the entire dial drive is a model of mechanical stability. For added ease and increased tuning accuracy, a section of the dial pointer is illuminated.

FM SECTION
The Radio Frequency (RF) section houses the complete FM-RF front-end and part of the AM RF circuit. A seven-section variable capacitor is the heart of the RF section. Four sections of the variable capacitor are in the FM front end and the remaining three are in the AM section. By interleaving the sections (AM-FM-AM-FM-etc.) spurious responses are significantly reduced. The four FM sections of the variable tuning capacitor provides a high degree of RF selectivity and excellent spurious rejection. Using the latest "state of the art" field effect transistors with a welldesigned variable tuning capacitor has provided the MX 113 with an excellent RF front-end ….

FM-IF AND DISCRIMINATOR SECTION
The MX 113 uses linear-phase IF filters. Each filter was designed from a FORTRAN computer program for minimumphase and constant delay. The mathematical complexity of the filter design procedure is almost beyond belief. Using numerical integration in the S-Plane, an "IBM" 1130 high speed computer spent eighteen minutes on the mathematics for the design of the IF filter. It would have taken a human engineer, working twenty-four hours a day, seven days a week, and working error-free three-hundred years to perform the same mathematical calculations! ...

FM STEREO MULTIPLEX SECTION
Mclntosh has developed a special detecting circuit used in the multiplex section. A particular advantage of this circuit is the elimination of the critical adjustments necessary with commonly used matrixing circuits. The circuit detects the L - R sidebands, then automatically matrixes the recovered information with the L + R carrier signal. This yields the left and right program output with maximum separation. ...

 AM SECTION
The AM-RF amplifier circuit includes a three section variable tuning capacitor in the metal enclosed shielded RF module which also houses the FM-RF front end. A three section variable capacitor is used for greater spurious rejection. The RF amplifier is unique. The circuit has constant sensitivity, constant selectivity, high image rejection across the complete AM band. Ordinary AM-RF circuits cannot do all of these simultaneously. This circuit design achieves equal sensitivity even at the low end of the band. Spurious, image, and intermediate frequency rejection are all superior. The same circuit delivers equal selectivity across the entire band. The Mclntosh circuit is unique in a superheterodyne AM receiver ...
...The AVC (automatic volume control) system was designed to prevent bursting or thumps when the AM is tuned through a strong signal. Distortion at low audio frequencies is minimized by using two AVC filter sections instead of the conventional one.

PHONO PREAMPLIFIER
There are three transistors in each channel of the phono preamplifier. The output of the third transistor is connected by a negative feedback loop to the emitter of the input transistor. The feedback loop reduces noise and distortion. It also provides precision RIAA frequency compenation required for magnetic phonograph cartridges. Feedback remains in effect even at 20 Hz, where gain is highest. The negative feedback also provides a low output impedance for the tape output. ...

L + R AMPLIFIER
The L + R amplifier consists of a single transistor connected as a voltage amplifier. Negative feedback is used around the summing amplifier to maintain low distortion and provide a low impedance for the center channel output.

POWER SUPPLY
The power supply of the MX 113 has received very special attention.
Three separate rectifier circuits are used. First, a fullwave rectifier supplies DC to all audio circuits. The second full-wave rectifier supplied DC to all tuner and multiplexdecoder circuits. The third supply provides DC to the AM circuit. The power supplies are elaborate in design. They use electronic filtering to insure the lowest possible background hum level, maximum stability, and extremely good regulation.
Specifications
FM Section
Useable Sensitivity2.5 microvolts at 100% modulation (± 75 kHz deviation) for less than 3% total noise and harmonic distortion,
Signal to noise ratio: 70 dB at 100% modulation,
Harmonic Distortion:
Mono : Will not exceed 0.3% at 100% modulation ±75 kHz deviation.
Stereo : Will not exceed 0.5% at 100% modulation ±75 kHz deviation.
Frequency Response:  ±1dB from 20 Hz to 15,000 Hz with standard de-emphasis
Capture Ratio1.5 dB
Spurious Rejection90 dB
Image Rejection95 dB at 88 to 108 MHz (IHF)
Stereo SeparationExceeds 35 dB at 1,000 Hz
Selectivity
Switch Setting : OUT /IN
Adjacent Channel : 6 dB /15 dB
Alternate Channel : 58 dB /88 dB
Tuning IndicatorD'Arsonval movement meter with increased sensitivity
Stereo Indicator: Stereo light activated by 19,000 Hz pilot signal only
AM Section
Sensitivity75 microvolts at 1,000 kHz (using external antenna input).
Signal To Noise Ratio45 dB
Harmonic Distortion1% at 30% modulation
Frequency Response: Down 6 dB at 3,500 Hz
Selectivity:
Switch Setting : OUT/ IN
Adjacent Channel : 35 dB/45 dB
Image Rejection: 65 dB; 540 kHz to 1600 kHz
Preamplifier Section 
Frequency Response±0.5 dB, 20 to 20,000 Hz.
Distortion:  Will not exceed 0.1% at 2.5 volts output, 20 to 20,000 Hz.
Input Sensitivity & Impedance:
Phono 1 and Phono 2: 2 millivolts for 2.5 volts output at 1,000 Hz, 47,000 ohms;
Auxiliary and Tape: 0.25 volts for 2.5 volts output; 250,000 ohms.
Voltage Amplification:
Phono 1, Phono 2 to Main output: 62 dB,  to Tape output: 42 dB.
Auxiliary, Tape to Main output: 20 dB,  to Tape output: 0 dB.
Output:
Main: 2.5 volts with rated input. Up to 10 volts can be developed without increase in distortion. FM will produce 10 volts output at 100% modulation.
Tape: 0.25 volts with rated input. Phono signal to 10 millivolts produces 1.2 volts output. FM will produce 1 volt output at 100% modulation. L + R 2 volts with rated input
Hum & Noise
Phono 1 and Phono 2: 72 dB below 10 millivolt input; (equivalent to less than 3 microvolts at the input terminals)
Aux-Tape: 85 dB below 2.5 volts output, (unweighted)
Bass Control-18 dB to + 16 dB at 20 Hz
Treble Control:  ±20 dB at 20,000 Hz
LF FilterFlat or roll off below 50 Hz, down 12 dB at 20 Hz
HF FilterFlat or roll off above 5,000 Hz, down 12 dB at 20,000 Hz.
Power Requirements120 volts, 50/60 Hz, 30 watts
Transistor Complement
2 - JFET
3 - MOSFET
30 - Silicon Planar
31 - Diodes
2 - Integrated Circuits (each contains the equivalent of 16 transistors and 8 diodes)

Mechanical 
SIZE:
Front panel :  16 inches wide (40.64 cm) by 5-7/16 inches high (13.81 cm);
Chassis :  15 inches wide (38.1 cm) by 13 inches deep (33.02 cm), including PANLOC shelf and back panel connectors;
Knob Clearance :  1½ inches (3.81 cm) in front of mounting panel.
WEIGHT:  26 pounds (11.79 kg) net, 38 pounds (17.24 kg) in shipping carton.
FINISH:  Front panel: Anodized gold and black with special gold/teal panel nomenclature illumination.
CHASSIS:  Chrome and black.
MOUNTING:  Mclntosh developed professional PANLOC

Features & Facilities  
Volume ControlPrecision "tracked" at al l listening levels. (0 to —65 dB). Does not change stereo balance as loudness is changed. The AC power ON/OFF switch is coupled with this control.
Balance ControlNatural balance at center position, attenuation of left or right channel by rotating control.
Loudness:  Loudness compensated or flat responseLoud- ness position boosts low frequencies for low level listening. Operates as a function of volume control position. Full compensation is obtained at lower volume levels and flat response is obtained at full volume.
SelectivityIncreases the ability of the tuner to separate a weak (distant) station from a strong (local) station on adjacent channels.
ModeSelects either stereo or mono operation
Phase ControlElectronically reverses phase in the left channel to correct "out of phase" program sources. MUTING: Suppresses the background noise and hiss normally heard between FM stations.
Tape MonitorPushbutton; compares recorded tape with program source while recording.
Muting AdjustModifies the noise rejection threshold on

FM Dial Scale IntensityModifies the brightness of the illumination of the front panel

Revox G 36

 Widely acclaimed throughout the world for its superb craftsmanship, the ReVox tape recorder is now available for the first time in U.S. and Canadian markets. The discriminating audiophile is well aware that there can be no compromise with quality and that the excellence of tape recordings is directly dependent on the skill and care used in the manufacture of their tape recorder. Quality control, constant checking and testing during every phase of ReVox manufacture and the use of highly rated components are the hallmarks of this superior instrument. ReVox is backed by a tradition of almost two decades in the manufacture of studio and broadcast tape equipment. The experience gained has resulted in ideas which have been incorporated into each ReVox. The ReVox, the instrument of choice by amateur and professional tape recordists, is also used in numerous industrial applications, in universities, as a teaching aid.. And as the focal point in home entertainment centers.  Its applications are seemingly limitless. Its quality is singular.
 Professional Features of the ReVox
Push-button electrical control of all operating modes.
Spool turnscounter.
Remote control facility.
Recorder can be used as an amplifier by switching off the capstan motor.
Additional low-impedence speakers can be connected.
Handy carrying case with pockets for two 10 ½" reels.
Constant speed hysteresis-synchronous heavy duty Pabst motor using direct drive of capstan. No belt of friction drives for the capstan shaft.
No pressure pads to clean - no pressure pads to wear out. This assures long head life and avoids longitudinal vibrations of the tape.
Three ring-core heads (2- or 4-track).
Separate pabst Outer-Rotor motors fro wind and rewind.
Tape speeds of 7½ and 3¾ i.p.s. obtainable through pole switching of capstan motor.
Reel size selector assures uniform tape tension for reels up to 10 ½ inches.
Recorder may be operated horizontally or vertically. Tape reels can be locked on to their shafts.
Two separate recording and replay amplifiers.
Cathode-follower low-impedance outputs.
Six-watt built-in monitor amplifier.
Two VU-meters with dynamic characteristics as per the ASA for individual record level control.
Both inputs may be mixed for mono-recordings.
Duoplay (sound with sound), Multiplay (sound on sound) and echo are possible wihout accessories.
Special Design of The ReVox

Three PABST Outer-Rotor Motors

Three motors are usually found only in professional tape recorders. This rather costly design assures optimum performance especially regarding to wow and flutter, and it is mechanically simple without containing any fast wearing parts.
 A design unique for an amateur recorder. Consisting of five diecastings, these parts, when attached to one another, from the very rigid unit which carries  the head-block and tape-guides. This assures perfect and permanent head alignment under the roughest operating conditions. The powerful Hysteresis-Synchronous-Motor and the heavy accurately balanced flywheel are mounted in a diecast cage. The runout of the capstan shaft must not exceed 0,001 mm in order to pass inspection. This is a degree of accuracy found only in studio an broadcast equipments.
 6/12 Hysteresis-Synchronous  Motor
The heavy-duty direct drive capstan motor is a hysteresis synchronous unit. The speed is electrically changed by controlling the number of poles. Maximum playing time can be had by setting the tape speed at 33 ¾ ips or superior quality by using a tape speed of 7 ½ ips.

Anti-Wow ans Anti-Flutter Design
The speed of the heavy-duty Pabst motor for the capstan is locked in with the power-line frequency, assuring remarkable uniformity of capstan shaft speed rotation. The motor is completely shielded, eliminating any stray megnetic motor flux. Precision bearings on the drive shaft removes the lateral pressure caused by the pinch roller and protect the motor from any uneven load.

Tape reels Up to 10 ½" Diameter
Maximum recording or playback time is assured through the use of reels having a diameter of 10½". These reels will accommodate up to 4800 feet of Lptape. Rewind can be accomplished in a few moments. Tape tension is controlled with a simple, easily operated, readily accessible control, which is designed so that large reels cannot be placed into position when it is set for reduced tape tension.

Separate VU-meters for each channel
The VU-meters on the ReVox are precision instruments with dynamic characteristics as required by the A.S.A. in the standard for volume measurement of complex waves. Accurate control of recording level is possible. Scale illumination of these meters is switched with the channel selector for added operating convenience.
 Solenoid Operated, Oversized Brakes
The brake bands are lifted off the linings during any operating mode. The required tape tension is achieved electrically by counter-torque on the winding motors. This assures minimum wear of mechanical parts. Braking is quick and positive from fast wind, even in the event of power failure.

Mechanical tape Stop
Because of the very fast winding speeds used by the ReVox, the instrument does not depend on metal contacts for stopping the recorder. A microswitch senses the end of the tape and turns off the motor circuits automatically after a real has been rewound. Automatic motor shutoff also takes place when a tape splice has opened.

Bulit-in Mixing Facilities
The mixing arrangements provide for the one pre-amplifier not in use for recording to be coupled with the other pre-amplifier through which the recording is being made, with neither gain control acting as a master. Thus any two signals may be mixed and recorded in the mono mode. The same controls are used for adjusting level and balence when recording stereophonically. Additionally, one channel can be set to playback while the other recording and all forms of sound-on-sound and sound-with-sound are possible.

Separate record and Playback - Amplifiers for both channels
The record amplifier hs a reserve gain of 14 dB before any distortion. Through the used of separate heads for record and play, continuous monitoring becomes possible.

Hum level
Every effort has been made to keep hum at an absolutely minimum level. The first stages of the amplifier have D.C. heated filaments. Teh power transformer has a grain oriented strip-wound core providing a minimum of stray magnetic field, reducing hum pickup.
 With the use of three motors the ultimate in simplicity can be achieved. Two motors for winding and rewinding and a third, the Capstan motor, for smooth and even tape transport during recording and replaying. There are no belts - other than that for the counter - no levers and no gears required for engaging the various operating modes
A glance at the amplifier chassis revoalscomponents of the highest quality not gonerally found in home equipment. Simple and easy to follow wiring takes the problems out of servicing.

Tubes
In addition to three silicon diodes and three selenium rectifiers, the ReVox uses a total of twelve dual function tubes. Each stage has been designed for single function operation. No simplification, with attendent tachnical compromise, has been permitted.

Oscillator Bias
A 70 kc push-pull oscillator is uded for highest erase efficiency, optimum signal-to-noise ratio and low signal distortion.
Specifications
Tape Speeds:  7½ and 3¾ i.p.s.
Speed Accuracy:  ±0,3%
Wow and Flutter:  max. ±0,1% at 7½ i.p.s.
Tape Speed Deviation:  0,3%, or less, from nominal
Frequency Response:
40 to 18,000 Hz at 7½ i.p.s.
40 to 12,000 Hz at 3¾ i.p.s.
Equalization:  NAB standards
Replay S/N Ratio:  better than 50 dB (referred to peak level)
Overall S/N Weighted:  55 dB at 7½ i.p.s. (for half-track operation)
Cross-Talk Rejection [Mono / Stereo]:  55 dB / 45 dB
Bias oscillator:  70 kc push-pull
Inputs per Channel:
Microphone : 3 mV at 1 megohm input impedance, 600 mV maximum 
Tuner : 50 mV at 1 megohm, 10 V maximum
Aux : 50 mV at 47,000 ohms (diode)
Outputs:
Two cathode-follower outputs
2-track  : 0,7 V
4-track  : 0,5V
Impedance:  5,000 and 100,000 ohms
Tubes and Semiconductors:
5 x ECC81;  1 X ECC82;  4 X ECC83;  2 X ECL86;
3 Silicon Diodes;  3 Selenium Rectifiers
Line Voltage:  117 V 60 Hz ( USA and Canada)
Power Consumption:  120 watts
Case Dimensions:  18½ x 12¼ x 11½ inches
Weight:  45 lbs approx.
Color:  Gray and aluminum frame with blue-gray plastic

H.H. Scott 3300

 Exclusive Scott perfectune.
The world's most accurate and reliable tuning device, obsoletes center-tuning meters by employing a digital computer to automatically flash an indicator panel light when best tuned for maximum reception (absolute center channel and lowest distortion).

True AM high fidelity
After years of costly experimentation, Scott engineers discovered the answer underlying true Am high-fidelity. Distortion so low that Scott AM is virtually undistinguishable from FM. Employing latest FET and Integrated Circuit techniques in the 3300, they throughly eliminated interference and drift. Weak stations now assume a new clarity, strong stations become totally distortion-free, and a new FET mixer improves cross modulation rejection and cuts adjacent stationinterference.

Solderless wire connections
A scott exclusive, "tension wrap" each wire around a terminal under tremendous torsion. Consequently, the 3300 possesses a dependability akin to aerospace and computer applications because the problems of cold or unsoldered connections are drasticly reduced.
 The world's first high fidelity IC Multiplex section (no larger overall than a cigarette filter) incorporates 31 transistors, 10 diodes and 29 resistors to ensure superior reliability and superior FM streo separation than conventional printed circuit construction.

Scott's quartz crystal lattice filter
In the tuner IF section never requires realignment or adjustment. Never … regardless of age or operating temperature. This revolutionary feature, never found before in receivers in this price range, also yields the extra divident of very low distortion and incredible selectivity.

F/C/O Circuity
Provides close to distortion-free listening, even at low volume levels. The 3300 incorporates Full Complementary Output Transistors to achieve perfect undistorted sound, over a wide power bandwidth at both 8 and 4 ohms … a vital factor when connecting extra speakers.
Specifications
Amplifier Section
Total Power:  130 watts at 4 Ω ±1 dB
IHF Music Power:  100 watts at 8 Ω
Continuous Power Output:
40 / 40 watts at 4 Ω
33 / 33 watts at 8 Ω
Harmonic Distortion:  0,8% at rated output
IHF Power Bandwidth:  20 Hz - 30 kHz
Input Sensitivity
Phono : 3,0 mV
Extra :  0,50 V
Tape :  0,50 V
Hum and Noise (below rated output):
Phono :  60 dB
Extra :  70 dB
Tape In :  70 dB
FM Multiplex Tuner Section
Tuning Range:  88 - 108 MHz
Sensitivity:  1,8 µV
Signal-to-Noise Ratio:  65 dB below 100% mod.
Total Harmonic Distortion:  0,6%
Frequency Response (FCC limit):   50 - 15,000 Hz, ±1 dB
Capture Ratio:  2,5 dB
Dial Calibrtion Accuracy:  0,5% of station freq.
AM Suppression:  55 dB
Separation at 400 Hz:  35 dB
Cross Modulation Rejection:  90 dB
FM Muting Switching Level:  3 - 30 µV (adjustable)
AM Tuner Section
Tuning Range:  535 - 1620 kHz
Bandwidth:  -3 dB = 8 kHz;  -6 dB = 10 kHz
Selectivity:  32 dB
THD (60% modulation):  2,0%
Usable Sensitivity:  100 µV/m at 600 kHz
Hum and Noise:  40 dB below 100% mod.
Spurious Response Rejection:  better than 60 dB
IF Rejection:  better than 33 dB

Image Rejection:  better than 48 dB

Sherwood S 7100

 Model S 7100 Stereo FM/AM Receiver
Here is of the traditional quality, value and features for which Sherwood is famous - at a modest price. An unparalleled command center for the finest high-fidelity music systems, the S7100 feature power to spare for even the most inefficient speaker systems, and distortion at listening levels is a mere 0,20%.
Sherwood's FM section incorporates the latest proven advances, such as hermetically sealed microcircuit and field-effect transistor circuitry for superior FM sensitivity and reliability.  Enjoy the operating ease provided by four rocker buttons that control FM interstation muting, loudness defeat, stereo-mono mode and tape monitor.
Sherwood's unique front panel tape jack (plus rear panel tape jacks) allows simultaneous recording on two records or dubbing from one recorder to another. Stereo headphone jack, too, for private listening. Speaker selector switch permits listening to your main set of stereo speakers (A) a remote set of stereo speakers (B) or both sets at the same time (A&B).
Tuning your favorite FM or Am stations is a joy with Sherwood's velvet touch "Flywheel tuning;" signal strength meter pinpoints when you are properly tuned to your station and a "Stereo" indicator light tells you if you are listening to a stereo station.  The S7100 achieves a reliability of performance backed by a full 3-year warranty on all parts. And Sherwood packages this superlative receiver in a distinctively styled handsome walnut cabinet, included at no extra cost. Whatever your wants - power, performance, beauty - Sherwood paces the field.

Features:
Hermetically sealed microcircuit, FET circuitry
Front panel extra Tape record/dubbing jack
FM "Hush" muting circuit
Handsome walnut case included
Specifications
FM Tuner Section
FM Sensitivity (IHF):  1,9 µV (-30 dB noise&dist)
Signal-to-Noise Ratio:  -65 dB
Capture Ratio:  2,8 dB
Suppression of AM:  -50 dB
Tuning Range: 87,5 to 108,5 MHz
Distortion:  0,5% at 100% Mod.
Spurious Response Rejection:  -87 dB
Stability:  ±15 kHz (±0.015%)
Image Rejection:  -78 dB
IF Rejection:  -90 dB
Alternate Channel Selectivity:  40 dB
Stereo Separation:  40 dB at 1 kHz
Frequency Response [Stereo]:  20 - 15,000 Hz ±1 dB
Antenna:  300 Ω balanced
AM Tuner Section
Sensitivity: 5 µV at 60% mod. For 6 dB S/N
Selectivity:  7,5 kHz at -6 dB
Frequency Response:  -6 dB at 4,0 kHz
Tuning Range:  530 to 1625 kHz
Image Rejection:  -50 dB at 1mhz
Antenna: Ferrite Rod (rotatable), High Imp. Input
Amplifier Section
Power Output
At 4 Ω : Music Power 80 W Total - Equivalent Music Power ±1 dB 100 watts RMS Power 30 watts X2
At 8 Ω : Music Power 70 W Total - Equivalent Music Power ±1 dB 85 watts RMS Power 25 watts X2
Harmonic Distortion:  1,0% at 8 Ω Rated Output, 0,29% at  10 watts
Intermodulation Distortion: 1,0 % at 8 Ω Rated Output, 0,20% at 10 watts
Stereo & Mono Speaker Output Impedance:  4, 8 or 16 Ω
Stereo Headphone Output:  High or Low Impedance
Stereo Recording Output:  200 mV, 2 k Ω
Power Bandwidth:  25 - 20,,000 Hz -1% Dist.
Frequency Response:
Aux:  30 Hz - 20 kHz ±2 dB
Phono :  RIAA Standard ±1,5 dB
Damping Factor:  30 : 1 at 8 Ω
Bass Control:  ±13 dB at 100 Hz
Treble Control:  ±13 dB at 10 kHz
Input Sensitivity (for rated output):
Phono : 1,5 mV
AUX : 200 mV
Input Capability for 1 % Dist:
Phono : 60 mV
AUX : 3,8 V
Hum and Noise (IHF):
Phono : -65 dB
AUX : -75 dB
Vol. Control Min> : _85 dB
Crosstalk:  -40 dB at 1 kHz
General
Power Requirements:  115 - 125 V, 50/60 Hz, 10 to 100 W fused
AC Outlets:  200 W switched
Dimensions (W x H x D):  17 ½ x 5 ¾ x 13 ½ inches

Weight (Shipping):  30 lbs

Ariston Transcription RD80 SL

 Increased efficiency in our new factory, together with new production methods, have enabled us to introduce the new RD80 into a price range much lower than was hitherto thought practical for a quality turntable. The RD80 maintains the Ariston philosophy of excellence of design, together with top class performance. It has the capacity to extract the maximum amount of information from the disc.
Like our other models the RD80 is entirely gimmick-free, and provides simply the best platform for carrying a vinyl disc without allowing that disc or any other extraneous energy sources to interfere with the stylus-to-groove interface.
The RD80 - quite the finest value turntable available "today".
At something like 2/3 the cost of its luxury finish brother the 110 , the RD80 sacrificies little considering the price difference. The finish is plainer, but nonetheless the plinth is wood veneered and the machined alloy pkatter weighs 2,45 kg. A single large pulley and foolprof drive runs at a 33-1/3 rpm via a conventional rubber belt, the three point sprung steel subchassis successfully isolating the platter/arm system from environmental disturbance.
Although improved since last reviewed, setting up is still time consuming, though helped by using underside bolts accessible without removing the bottom cover. Possibly as a result of the reduced platter mass, this deck was more stable in its set up and remained so for longer than the Rd110. The plinth will accept some of the longer arms, and the lid is a generously thick dark-tinted PVC moulding."

 "Performingwell on the labtests, wow and flutter, torque, rumble, start up time and speed error were all very good for the class and type of deck.  A trace of 100 Hz motor breakthrough was however present, measuring -65 dB unweighted.  The sensible flat mat gave an above average disc impulse result.  If anything its isolation and acoustic rejection were superior to those of the 110, probably because of the more stable subchassis behaviour, and good to very good results were obtained here.

Sound Quality
In tonal balance the RD80 was judged quiete good with a well integrated character, if slightly dull. The sound field was quite  secure and stable,demonstrating fairly good bass as well as a precise image, with good focus and fair depth - all strong plus points at the price."
 Resonance Isolation
Optimum resonance isolation is achieved in all Ariston turntables. Relatively slow running AC syncgronous 24-pole motors now extensively used in audiophile turntables were first introduced by Ariston in 1969.  the motor are completely divorced from the subchassis and tone arm assembly. All frequencies are therefore contained within an innocous area.

The Sub-Chassis
We construct the sub-chassis in precision pressed heavy gauge steel or aluminium which is perfectly flat on all planes.  The bearing housing and the tone arm board are rigidly mounted to the sub-chassis. The entire assmbly is isolated and has a natural frequency in the area of 4 Hz.

The Tone Arm Board
The Ariston tone  arm board is protected from damaging infrasonic frequencies in the area of 7 - 16 Hz, which are set up by the arm's oscillation. These frequencies are moved to a lower harmless value by the use of acoustically dead materials.

The Platter
All Ariston platters incorporate peripheral mass distribution which, by maintaining a flywheel effect, smooth out the undesirable effects of wow and flutter.  It should also be noted that the parameters of wow amd flutter by which turntables are commonly judged, does not indicate the turntable.s ability to retrieve information.
 The Belt Drive
In a no-compromise turntable, designed for maximum isolation, any other method of drive is totally unacceptable. The flat neoprene belt precision ground to a fine finish isolates the disc-carrying platter from the motor. A flat belt is employed for absolute speed stability - a round belt can twist and thereby create wow.  Direct drive does not isolate, due to the fact that it cannot be de-coupled from the platter. This creates resonance at the vinyl/stylus interface.

The Main Bearing
Our shaft bearing is unoque. Before we go on to explain why, it would be helpful for you to remember that a piece of cigarette paper measures one thousandth of an inch in thickness.
The bearing has to eliminate vertical movement which manifests itself as rumble (a low Growl) through the speakers. Ariston turntables have a typical rumble figure of -74 dB weighted. Any figure in excess claimed by other manufactures must be treated with some degree of scepticism due to the environment and the inadequacies of test equipment currently available.
The shaft is precision ground from hardened high tensile chrome steel to within a tolerance of ± .0003 inches. That is two tents of one thousendth of an inch. One fifth the thickness of a cigarette paper.
The surface finish is a mirrorlike 4 - 6 microns and the hardness is to 64° rockwell.
The shaft rest on a spherically precise captive ball for single point contact.
The bearing hpusing is honed to perfectly amtch the shaft.
Take the belt off an Ariston turntable and turn the hub and platter by hand.
Note how friction free the entire assembly is - it  will simply run on and on and on.

 Features RD80SL
Two speed manual 33-1/3 and 45 prm
A.C. Synchronous Motor
Two piece fully machined concave platter with record clamp.
Precision made single point bearing.
Closed transmission loop isolation.
Real wood veneered acoustically damped board cabinet and metal base. 
Access points for adjustment and adjustable feet.

Specifications
Type:  Belt drive
Speed Options:  33-1/3 rpm
Absolute Speed Error:  +0,35%
Speed Drift (1 hour/load variation):  Synchronous/-0,15%
Wow and Flutter (DIN):  0,07%
Rumble (DIN B):  -76,5 dB
Start Up Time To Audible Stabilisation:  3,5 sec.
Platter Mass:  2,45 kg (good damping)
Type of Mains Lead:  3 core
Connecting leads:  Phono + earth
Vibration Sensitivity/Shock Resistance:  Good/fairly good
Hum Level and Acoustic Feedback:  Very good
Acoustic Breakthrough and Resonances:  Very good
Subjective Sound Quality:  Good
Finish and Engineering:  Very good
Size (W x D x H):  445 x 360 x 170 mm

Clearance for Lid Rear:  40 mm