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





Luxman CX-1

Ultimate Fidelity Sound Reproduction by Means of DC Configuration
Lux's unique philosophy of ''real time proces'' is taken into account in addition to through study of conventional distortion shown by continuous signals. To avoid large capacitor harmful to tonal quality pure DC amplifier circuit is employed.

Perfect Muting Circuit
In the case of a head amp which deals with the lowest level signals, even the slightest thump noises at On/Off switching time cause a serious problem. With this unit, a muting circuit is provided that short-circuits the output by means of realy for about 10 seconds after the power is turned on or off, which completely removes this nuisance.

Necessary and Sufficient Noise Ratio
At the 30 dB position, the input-equivalent noise is -150 dB/V, input shorted, based upon IHF A-curve. Generally speaking, with a head amp whose 1st stage is composed of transistors, the S/N ratio is excellent when a low-impedance cartridge is used, but it is audibly deteriorated at the time of use of high-impedance cartridge. With this unit, FET's are employed at the 1st stage, and the S/N ratio is immune to fluctuation of impedance. At the 20 dB position the noise level is -148 dB/V.

Amplitude Selector
Most MC cartridges are classified into 2, one with an extremely mall output voltage and the other with a relatively large output voltage. To handle both types, the amplitude selector is abile to select either 20 dB or 30 dB gain. Also, the ''Bypass'' position is useful when an MM cartridge is used. needless to say, appropriate counter-measures are taken against shock noises at the time of switching.

Perfect Elimination of External Inductance Noise
The inside is shielded by quality silicon steel plate so as to minimize the noises caused by the inductance of transformer of amp or phono-motor of turntable, and also the input terminal is directly wired to the printed circuit board with the optimum earth point, which ensures virtually perfect elimination of external inductance noise.

High-Quality Power Supply Section
Ripple ingredients are suppressed by means of a ripple filter, and at the high sensitivity constant voltage power supply circuitry effective counter-measures are taken to prevent power source noises. In addiction, a decoupling circuit of large capacitance is used.

Other Features
Contact resistance increases as time goes by. To ensure ultra low contact resistance and to prevent its possible deterioration with the lapse of time, gold-plated pin-jack terminals are employed. naturally, specially selected components are used, and the best-quality metalic film resistors, precision potentiometers, and metalized film capacitors, are placed at optimum points.

Specifications

Voltage Gain:
20 dB (MC cartridges of middle output type)
30 dB (MC cartridges of low output type)
Frequency Response: 5 Hz - 500,000 Hz (-1 dB)
Total Harmonic Distortion:
no more than 0,003% (20 dB position, output 300 mV, 20 -20,000 Hz)
no more than 0,005% )30 dB position, output 300 mV, 20 - 20,000 Hz)
Input Equivalent NOise:
-150 dBV (30 dB position, iput short-circuited, RIAA, IHF-A weighted)
-148 dBV (20 dB position,input short-circuited, RIAA, IHF-A weighted)
Input Overloaded Voltage: no less than 90 dB (1 kHz); no less than 80 dB (20 kHz)
Input Impedance: 100 ohms
Output Impedance: 100 ohms
Power Consumption: 5 W
Dimensions (W x H x D): 138 x 77 x 305 mm (5-7/16'' x 12'' x 3-1/32'')
Weight: 2,7 kg (5,9 lbs) net

Yamaha YH-1000 (1978)

These headphones feature Yamaha's exclusive Orthodynamic Design, a concept radically different from conventional dynamic or electrostatic types. Instead of an ordinary voice coil and diaphragm, it uses an ultra thin, low mass, polyester film diaphragm, sandwiched by a pair of powerful disc magnets. The voice coils are photo-etched on the surface of the diaphragm. The performance that results is marked by smooth, even response over the entire audible frequency range, low distortion, and clear imaging. The YH-1000 is a delight to wear, also: the earcups use a supra-aural design which eliminates listening fatique, and height and tilt adjustment ensure comfort over long hours of use.
"YH-1000 ia an orthodynamic headphones which has emerged as a fruition of Yamaha's unique technology of acoustic equipment development. YH-1000 is provided with a capacity of distortion-free broad band reproduction from heavy low sound to ultra high band which is characteristic of a horizontal drive system. YH-1000 also incorporates a rare earth element magnet which generates strong flux and an aluminium diecast housing which eliminates unnecessary vibrations. These features contribute to the production of powerful yet clear sound. YH-1000 is the outcome of our quest to provide comfortable feeling of fitness to your ears and ease in use, which we hope you will find satisfactory".

Specifications
Type: Orthodynamic
Diaphragm
diameter: 50 mm
Film diaphragm: 12 µm polyester
Coil diaphragm: 9 µm copper foil
Magnet: Cerium series cobalt
Frequency
response: 20 - 20,000 Hz
Sensitivity: 103 dB/1m/1W
Impedance: 100 Ω
Rated input: 3 W
Max. instant.
Input: 10 W
Total Harmonic
Distortion: 0,3% or less at 90 dB SPL
Weight: 500 g (1 lb 2 oz)

Nakamichi OMS-1 /1A /1E (1988)

Nakamichi OMS-1 Single Compact Disc Player

Features :

3 Beam Laser Pick Up.

2 Times Oversampling Digital Filter.

16-bit D/A (digital to analog) Converter Technology.

5th Order Active Low-Pass Filter.

Floating Disc Drive Mechanism with Precision Centering for Protection against Disturbance.

CLV (Constant Linear Velocity) Servo System.

RCA phono analogue outputs

Specifications :

Principle: Digital Audio System

DAC :

2 x Burr Brown PCM56P,

2 x oversampling digital filter LC7860N,

Transport: AT-D16 / D654 / OC82727A

Frequency Response: 5 Hz - 20 kHz, +0.5 dB -1 dB

Signal to noise: better than 96 dB (IHF A-weighted)

Sensing Method: Non-Contact Optical System (Semi-conductor Laser)

Error Correction: CIRC by Principle

Number of Channels: 2 Channel Stereo

Total Harmonic Distortion (THD): 0.006%

Channel Separation: better than 88 dB

Dynamics Range: better than 90 dB

Quantization: 16 Bit Linear

Sampling Frequency: 44.1 kHz

Speed: About 200-500 rpm (Constant Linear Velocity)

Output Level (Line 1 kHz, 0 dB): 2.5 V / 600

Power requirement: 120/240 Volts (50/60 Hz)

Power Consumption: Max 14 watts

Dimensions (W x H x D): 430 x 75 x 270 mm

Weight: approx. 3,7 kg

McIntosh MDA 1000

Hear all there is to hear from your existing CD collection. Let the MDA1000 modify your music data stream from 16 bits to 24 bits, and to a sampling rate of 768kHz all while still in the digital domain. Then the MDA1000’s eight, 24 bit Burr Brown digital converter take things from there. This processing allows such gentile filtering to the converted signal that the original musicality comes through, instead of the sound of the digital circuits themselves. The difference is easily heard. Listen and you will be amazed at how older discs rival, or often exceed, the sound of the new “higher resolution format” discs.

The MDA1000 D/A Converter and its matching MCD1000 CD Transport represent the introduction of a new and elite product category from McIntosh. The philosophy behind this enhanced level of McIntosh products is nothing but the best…to deliver the absolute highest possible performance without design constraints. Available only through McIntosh Authorized Premier Dealers, the MDA1000 and the MCD1000 are merely the beginning of this exclusive line.

Seven Digital Inputs

3 Coaxial Inputs on RCA Jacks

3 Optical Inputs

1 Balanced Digital in on XLR Jack

Balanced (XLR) Outputs

Unbalanced (RCA) Analog Outputs

Front Panel Volume Control with

Optional Bypass Function

3D Glass Front Panel

Fiber Optic Lighting

Remote Control

POWER SUPPLY

Multiple layers of regulation provide clean power to all critical circuits. The power transformer has the lowest noise field of any available.

CIRCUIT SHIELDS

Each D to A Converter is shielded to avoid any chance of hum or noise getting through.

VOLUME CONTROL

Precision front panel and remote volume control allow the MDA1000 to function as a preamplifier in an all-digital system. Setup programming allows volume control bypass if desired.

FRONT PANEL DESIGN

3D front panel glass design is illuminated with long-life, cool-running fiber optics that make operation in low light easier. Silk screening on the inside of the glass front panel prevents wear of the nomenclature, ensuring lasting beauty and highest resale value…a McIntosh hallmark feature.

Specifications:

ANALOG AUDIO

FREQUENCY RESPONSE:

±0.5 dB from 4 Hz to 45 kHz (sampling frequency 96 kHz and 88.2 kHz)

±0.3 dB from 4 Hz to 22 kHz (sampling frequency 48 kHz)

±0.3 dB from 4 Hz to 20 kHz (sampling frequency 44.1 kHz)

±0.3 dB from 4 Hz to 15 kHz (sampling frequency 32 kHz)

TOTAL HARMONIC DISTORTION: 0.002% at 1 kHz

A-WEIGHTED SIGNAL-TO-NOISE RATIO: Better than 110 dB

DYNAMIC RANGE:: Better than 100 dB (1 kHz)

RATED OUTPUT VOLTAGE:

2V Unbalanced Outputs (BYPASS ON Mode)

6V Unbalanced Outputs (BYPASS OFF Mode)

2V Balanced Outputs (BYPASS ON Mode)

6V Balanced Outputs (BYPASS OFF Mode)

DIGITAL AUDIO SPECIFICATIONS

DIGITAL AUDIO FORMAT: IEC958, S/PDIF

COAXIAL INPUTS (1, 2, AND 3): 0.5V p-p at 75 Ω

OPTICAL INPUTS (4, 5, AND 6): -15 ~ 20 dBm

XRL INPUT (7): 5V p-p at 110 Ω

SAMPLING FREQUENCIES: 96 kHz, 48 kHz, 44.1 kHz and 32 kHz

POWER REQUIREMENTS: 100 -240 Volts, 50/60Hz, 20W

DIMENSIONS (W x H x D): 445 x 152 x 410 mm (17½ x 6 x 16 inch)

WEIGHT: 11 kg (24 lbs.)

McIntosh MCD 1000

Touch the open/close button to send the machined aluminum disc tray gliding out to receive your CD. The MCD1000 takes it from there. Extraction of all of the data on the disc without errors is what this transport is about. The machined aluminum top and side panels, combined with fiber optically lit 3D glass front panel not only add lasting beauty, but also provide a massive enclosure for the disc drive transport. Combined with a new floating table for the optics, the MCD1000 laser pick-up is incredibly well isolated from the outside world. Vibration never reaches the optical system, reducing errors. Reduced errors results in full retrieval of every detail of your music.

The MCD1000 CD Transport and its matching MDA1000 D/A Converter represent the introduction of a new and elite product category from McIntosh. The philosophy behind this enhanced level of McIntosh products is nothing but the best…to deliver the absolute highest possible performance without design constraints. Available only through McIntosh Authorized Premier dealers, the MCD1000 and the MDA1000 are merely the beginning of this exclusive line.

Three Types of Digital Outputs:

Coaxial Output on RCA Jack

Optical Output Jack

Balanced Digital AES/EBU

110 ohm XLR Output

2-Way Repeat Function

16-Selection Random Programming

Data In/Out Jacks

3D Front Panel Design

Fiber Optic Lighting

Remote Control


POWER SUPPLY

Multiple layers of regulation provide clean power to all critical circuits. The R-Core power transformer has the lowest noise field of any available.

TRANSPORT ISOLATION

High power systems with high power woofer systems place greater demands on the CD transport. The MCD1000 is designed to work under these conditions without producing tracking error that must be corrected later down the data stream.

MACHINED TOP AND SIDE PANELS

The top and sides of the MCD1000 are machined from thick aluminum panels with a smooth black anodized finish. In the recessed area of the top panel is a glass panel screened with a block diagram of the MCD1000’s circuitry.

FRONT PANEL DESIGN

3D front panel glass design is illuminated with long-life, cool-running fiber optics that make operation in low light easier. Silk screening on the inside of the glass front panel prevents wear of the nomenclature, ensuring lasting beauty and highest resale value

…a McIntosh hallmark

Specifications

DIGITAL AUDIO FORMAT: IEC958, S/PDIF

DIGITAL OUTPUTS:

Optical: -15 ~ -20 dBm

Coaxial: 0.5V p-p at 75 Ω

XRL: 5V p-p at 110 Ω (AES/EBU)

TRANSPORT:

Pickup: Optical 3-beam laser

Objective Lens Drive System: 2-dimensional parallel

Laser Type: GaAIAs Semiconductor

Laser Beam Wavelength: 780 nm

DIGITAL SIGNAL FORMAT:

Sampling Frequency: 44.1 kHz

Quantization Bit: 16-bit linear/channel

Modulation Code: Eight to fourteen modulation

Error correction: Cross Interleave Reed Solomon

POWER REQUIREMENTS: 100 - 240 Volts, 50/60 Hz, 20W

DIMENSIONS (W x H x D): 445 x 152 x 41 mm(17½" x 6"x 16")(including knobs and feet)

WEIGHT: 12.5kg (27-1/2 lbs.) net

JVC JR-S 501

JVC JR-S501

DC Integrated Stereo Receiver

The top-of-the-line JR-S501 includes massive and super-clean DC power amplification, advanced phono equalizer and tuner circuitry, S.E.A. Graphic Equalizer, clean "knobless" looks. FM tuner offers first-rate sensitivity and selectivity from its low-noise FET fronted, phase-linear ceramic filter IF and PLL multiplex demodulator with built-in pilot signal canceller. Nothing gives you more high fidelity expertise.

JVC's new line of stereo receivers offer outstanding models to suit your budget, power output requirements and musical tastes. Rach one incorporates the finest JVC technology for reliable performance over long years of use. Four of the receivers use a supersmooth DC power amplifier and the hi-fi accuracy and flexibility offered by JVC's S.E.A. Graphic Equalizer and S.E.A. Recording, superb FM/AM tuner technology and more. DC Amp design improves musical quality for more accurate reproduction of all musical sources, a virtue you'll hear immediately. DC also reduces all types of distortion, expands frequency response from zero HZ to 100 kHz - and, overall, leads to the elimination of coloration and poor transient response. The DC power amp in every JVC receiver features an exceptionally low 0,03% total harmonic distortion, more reasons why with JVC you'll move Closer to theMusical Truth.

SEA all the way

All four receivers offer JVC's five-zone graphic equalizer for more complete control of the music spectrum than conventional tone controls. You can attenuate or accentuate any of five separate musical bands and as an added feature we've incorporated a special button so that the S.E.A. circuit can be switched to your tape deck.

Pushbutton Source Selectors

A horizontal panel of pushbuttons provides total control over all functions. And brilliantly illuminated LED's instantly indicate the program source. Professional type slider controls set volume and balance. Combine all these exclusive features with high sensitivity and tuning precision, thumb control tuning wheel and accurate dual-metering and you'll see just how revolutionary the new JVC DC integrated stereo receivers are.

Specifications :

Output Power: 120 watts per channel ( min. RMS, both channel driven)

Frequency Response: 5 Hz - 40,000 Hz; +0,0 dB -1,0 dB

Load Impedance: 4 - 16 ohms

Total Harmonic Distortion: 0,008% (at half rated power, 1kHz, 8 ohms)

Intermodulation Distortion: 0,01% (at rated output)

Damping Factor: 70 at 8 ohms, 1kHz

Input Sensitivity/impedance:

Phono : 2,5 mV/47 kohms

Aux, Tape : 210 mV/50 kohms

S/N ratio (IHF Short-Circuit a Network):

Phono : 75 dB

Aux, Tape : 95 dB

Recording Output: Pin: 210 mV; DIN: 30 mV (80 kohms)

Phono Equalizer Deviation: ±0,2 dB from 20 Hz - 20 kHz

Phono Overload: 200 mV (RMS)THD 0,03%

S.E.A. Center Frequencies: 40, 250, 1 k, 5 k, 15 kHz

S.E.A. Control Range: ±12 dB

FM Sensibility: 10,3 dBf

50 dB Quieting Sensitivity: 37,2 dBf (stereo)

FM Capture Ratio: 1,0 dB

FM Alt. Channel Selectivity: 80 dB

S/N Ratio FM: 70 dB (stereo)

Dimensions (W x H x D): 22-1/16 x 6-9/16 x 16-15/16 inches

Weight: 46,2 lbs

JVC JR-S 401

JVC's new line of stereo receivers offer outstanding models to suit your budget, power output requirements and musical tastes. Rach one incorporates the finest JVC technology for reliable performance over long years of use. Four of the receivers use a supersmooth DC power amplifier and the hi-fi accuracy and flexibility offered by JVC's S.E.A. Graphic Equalizer and S.E.A. Recording, superb FM/AM tuner technology and more. DC Amp design improves musical quality for more accurate reproduction of all musical sources, a virtue you'll hear immediately. DC also reduces all types of distortion, expands frequency response from zero HZ to 100 kHz - and, overall, leads to the elimination of coloration and poor transient response. The DC power amp in every JVC receiver features an exceptionally low 0,03% total harmonic distortion, more reasons why with JVC you'll move Closer to theMusical Truth.

SEA all the way

All four receivers offer JVC's five-zone graphic equalizer for more complete control of the music spectrum than conventional tone controls. You can attenuate or accentuate any of five separate musical bands and as an added feature we've incorporated a special button so that the S.E.A. circuit can be switched to your tape deck.

Pushbutton Source Selectors

A horizontal panel of pushbuttons provides total control over all functions. And brilliantly illuminated LED's instantly indicate the program source. Professional type slider controls set volume and balance. Combine all these exclusive features with high sensitivity and tuning precision, thumb control tuning wheel and accurate dual-metering and you'll see just how revolutionary the new JVC DC integrated stereo receivers are.

Specifications

Output Power:

85 watts per channel,( min. RMS, both channel driven)

90 watts per channel into 8 ohms (1kHz, THD 0,03%)

110 watts per channel into 4 ohms (1kHz, THD 0,03%)

Frequency Response: 5 Hz - 40,000 Hz; +0,0 dB -1,0 dB

Load Impedance: 4 - 16 ohms

Total Harmonic Distortion: 0,008% (at half rated power, 1kHz, 8 ohms)

Intermodulation Distortion: 0,01% (at rated output)

Damping Factor: 70 at 8 ohms, 1kHz

Input Sensitivity/impedance:

Phono : 2,5 mV/47 kohms

Aux, Tape : 210 mV/50 kohms

S/N ratio (IHF Short-Circuit a Network):

Phono : 75 dB

Aux, Tape : 95 dB

Recording Output: Pin: 210 mV; DIN: 30 mV (80 kohms)

Phono Equalizer Deviation: ±0,2 dB from 20 Hz - 20 kHz

Phono Overload: 200 mV (RMS)THD 0,03%

S.E.A. Center Frequencies: 40, 250, 1 k, 5 k, 15 kHz

S.E.A. Control Range: ±12 dB

FM Sensibility: 10,3 dBf

50 dB Quieting Sensitivity: 37,2 dBf (stereo)

FM Capture Ratio: 1,5 dB

FM Alt. Channel Selectivity: 80 dB

S/N Ratio FM: 70 dB (stereo)

Dimensions (W x H x D): 22-1/16 x 6-9/16 x 16-15/16 inches

Weight: 35,4 lbs

Onkyo TX-1500

Onkyo's TX-1500 proves that superb performance is a function of design and construction. This receiver has been designed for sophistication providing a variety of convenience usually found only in highest priced units. Start with Servolock, Onkyo's unique tuning system, which automatically tuners in the best reception with minimum distortion and maximum separation when the dial is set near the desired station. Once the signal is locked in, it maintains the best reception without any drift, even though changes in temperature and frequency occured

The tuner using an ingeniously designed FET/3-gang variable capacitor front end. Onkyo's TX-1500 provides 2,3 μV of usable sensitivity in mono and 5 μV in stereo mode, with in IF rejection ratio of 80 dB for extraordinary sensitivity without distortion.

2-stage, 4 element ceramic filters and quadrature detector deliver maximum frequency response with minimal distortion in the IF stage. Clean, sharp stereo reception is assured through the use of Phase Locked Loop Mutiples circuitry which synchronizes the stereo pilot signal in both phases. Phase shift is avoided and stereo separation is stable at 35 dB (1 kHz) and 30 dB (100-10,000 Hz)

The TX-1500 uses direct coupled differential main amplifier design, eliminating output capacitors which cause even more distortion. This configuration delivers excellent transient response. Overall frequency response is 20-20,000 Hz, +/-1 dB.

Power output is 75 watts per channel, minimum RMS at 4 ohms or 8 ohms, both channel driver from 20 Hz to 20 kHz with no more than 0,5% THD.

Servolock ofcourse, is the most important feature. Smooth, FM muting effectively eliminates harsh, interruptive noise as you change station.No other receiver in this price class has our transient noise killer circuit to eliminate pops and crackles when the power is tunned on. And youhave a dual tape monitor system and one-way dubbing. Plus provision for two speaker systems. And thermal protection in the power transformer.

Onkyo delivers the precision tuning of Servolock and inherent quality.Because Onkyo delivers performance... regardless of cost.

Specifications

Amplifier section

Power Output Dynamic: 70 watts total at 4Ω, 0,5% THD

Power Output Continuous:

15 +15 watt min. RMS at 8Ω or 4Ω, both channels driven, 20Hz-20kHz, with 0,5% THD

17 +17 watt min. RMS at 8Ω both channels driven, 1 kHz, 0,5% THD

20 +20 watt min. RMS at 4Ω both channels driven, 1 kHz 0,5% THD

Total Harmonic Distortion: 0,5% at rated power (0,3% at 1 watt output)

IM Distortion: 0,5% at rated power (0,3% 1 watt output)

Damping Factor: 20 (8Ω, 1 kHz, 10 watts)

Frequency Response: 20 - 30,000 Hz, ±1 dB

Sensitivity and Impedance:

Phono: 2,5 mV/ 50 kΩ

Tape Play: 150 mV/ 50 kΩ

Tape Rec: 150 mV/50 kΩ

Phono Overload: 100 mV RMS, 1 kHz, 0,5% THD

Bass Control: ±12 dB at 100 Hz

Treble Control: ±10 dB at 10 kHz

Signal-to-Noise Ratio:

Phono: 65 dB (IHF C Network)

Tape: 80 dB (IHF C Network)

RIAA Curve Deviation: ±0,8 dB at 30 Hz to 15 kHz

Tuner section

Tuning Range:

FM : 88 - 108 MHz

AM : 530 - 1605 kHz

Usable Sensitivity:

FM mono: 2,3 μV (12,4 dBf) IHF; 1,8 μV (S/N 26 dB, 40 kHz Devi>) DIN

FM stereo: 5 μV (19,2 dBf) IHF; 50 μV (S/N 46 dB, 40 kHz Devi.) DIN

50 dB Quieting Sensitivity:

FM mono: 4,5 μV (18,3 dBf)

FM stereo: 50 μV (39,2 dBf)

Intermediate Frequency: FM = 10,7 MHz; AM = 455 kHz

Capture Ratio FM: 2 dB

Image Rejection Ratio: FM = 45 dB; AM = 40 dB

Signal -to-Noise Ratio: FM mono = 65 dB; FM stereo = 60 dB; AM = 40 dB

Alternate Channel Att. FM: 60 dB

Selectivity FM: 42 dB DIN (±300 kHz, 40 kHz Devi.)

AM Suppression Ratio: 50 dB

Harmonic Distortion: FM mono = 0,25%; FM stereo = 0,5%; AM = 0,9%

Frequency Response: 30 - 15,000 Hz ±1,5 dB

Deemphasis Switch: 50 μs/ 75 μs

Stereo Separation FM: 35 dB at 1 kHz; 30 dB at 100 - 10,000 Hz

Muting level: 3 μV

Stereo Threshold: 3μV

Servo Lock lamp level: 3μV

Spurious Rejection: 78 dB (1/2 IF)

Sub Carrier Suppression: 40 dB

Tuning meter: Signal strength meter

General

Semiconductors: 1 FET, 12 Transistors, 7 ICs, 21 Diodes

Power Supply Rating: 110/120/220/240 V AC 50/60 Hz

Antennas

FM: 300 Ω balanced

AM: built in ferrite core antenna and external terminal

Dimensions (W x H x D): 439 x 149 x 310 mm (17-5/16 x 5-7/8 x 12-3/16 in)

Weight: 7,3 kg (16,1 lbs)

SAE TWO R12


The 120 watt per channel R12 receiver from SAE TWO
It shares all the basic performance and design characteristics of the R18 minus a few of the added conveniences. Like the R18 it offers wide and narrow IF band selection. (Wide for normal reception and narrow for weak signals or unusual reception conditions)
Also like the R18, the R12 features optional infrared remote control capability for convenient turn-on, volume, balance and tuning.
You're provided state-of the-art digital readout, flourescent bar graph displays and much more:
Synthesized Touch Tuning.
Quartz lock.
External processor Input.
Tape EQ.
Single Strata Voltage Amplifier.
Full Complementary Outputs.
Infrared remote Control (Optional).
Parametric EQ.
Low Noise Phono IC's.
Moving Coil Input.
Relay Speaker Protection.

Specifications (IHF-202A, 1978 STD.)

Power (into 8 ohm from 20 - 20,000 Hz): 120 watts
Total Harmonic Distortion (from 250 mW to full rated power is less than): 0.05%
Intermodulation Distortion (SMPTE STD< 250 mW to rated output, lesss than): 0.05%
Power Bandwidth (1 kHz, 0.1% THD, 8 ohms): 10 Hz - 60 Hz
Damping Factor (1 kHz, 8 ohms): >40
Frequency Response:
Phono MC: ±0.5 dB
Phono MM: ±05 dB
Aux, Tape, Ext Pros: ±0.5 dB (20 Hz - 20 kHz); +0.5/-3 dB (5 Hz - 100 kHz)
Signal to Noise Ratio (IHF-A):
Phono MC: 80 dB
Phono MM: 84 dB (5 mV, IHF load); 94 dB (10 mV, shorted)
Aux, Tape, Tun: 80 dB (1 watt output); 100 dB (rated output)
Residual Noise (IHF-A): 10 mV
Input Sensitivity (1W/ Rated Output/Impedance):
Phono MC: 0.01 mV/0.25 mV/500 ohms
Phono MM: 0.11 mV/2.5mV/47 kohms
Aux,Tape, Ext. Pros. Tuner: 6.7 mV/150 mV/50 kohms
Output Level - Tape Out, Ext. Pros: 150 mV
Maximum Input Level:
Phono MC: 12 mV
Phono MM: 150 -300 mV
Aux, Tape, Ext. Pros., Tuner: 4 V
Parametric EQ
Low:
Level: ±16 dB
Frequency: 20 Hz - 1.2 kHz
Bandwidth: 0.3 - 3.6 oct.
High:
Level: ±16 dB
Frequency: 1.2 kHz - 20 kHzz
Bandwidth: 0.3 - 3.6 oct.
Filter: 6 dB/octave at 30 Hz
Loudness Compensation (level -30 dB): =6 dB at 10 kHz, +8 dB at 100 Hz
Audio Muting: -20 dB
Volume Tracking Error (0 - 70 dB): ±1 dB
TUNER SECTION
Usable IHF Sensitivity:
Mono: 1,8/10,3 μV/dBf
Stereo: 4/17,3 μV/dBf
50 dB Quieting Sensitivity:
Mono: 4/17,3 μV/dBf
Stereo: 30/34,7 μV/dBf
Signal-to-Noise Ratio (IHF):
Mono: 76 dB
Stereo: 70 dB
Image Rejection Ratio: 85 dB
Spurious Response Ratio: 95 dB
IF Rejection Ratio: 95 dB
AM Suppression: 55 dB
Capture Ratio: 1,5 (W)/1,0 (N) dB
Alternate Channel Selectivity: 35 (W)/70 (N) dB
Harmonic Distortion Mono:
100 Hz : 0,09%
1 kHz : 0,08%
7,5 kHz : 0,22%
Harmonic Distortion Stereo:
100 Hz : 0,15%
1 kHz : 0,15%
7,5 kHz : 0,30%
Stereo Separator:
50 Hz : 46 (W)/38 (N)
1 kHz : 48 (W)/40 (N)
10 kHz : 40 (W)/36 (N)
Frequency Response: 30 -15 kHz, +0,5 dB -2 dB
Muting Sensitivity: 7 μV
Subcarrier Suppression: 65
Output Level: 150 μV
AM Section
Usable Sensitivity: 15 μV
Selectivity: 32 dB
Signal-to-Noise Ratio: 45 dB
Harmonic Distortion: 0,5 dB
Image Rejection Ratio: 45 dB
IF Rejection Ratio: 40 dB
Output level: 150 μV
Dimensions (W x H x D): 559 x 165 x 457 mm (22 x 6½ x 18 inch)
Weight: 21 kg (47 lbs)




Kenwood KT-405 (1979)


Great black-on-silver styling that matches the Kenwood KT-413 Auto Search-and-Scan AM/FM Tuner. Advanced circuitry and professional controls complete this powerful amplifier.


Features

HI-SPEED™ amplifier for faster transient response for unprecedented musical clarity and crispness.

55 watts per channel, min. RMS both channels driven at 8 ohms, 20Hz -20kHz, with less than 0,05% THD

Wide band frequency response down to 2Hz for full bass without phase distortion

Professional fast-acting peak power meters

Noise-free phono section: 83dB signal-to-noise ratio (5mV input)

Power Amp Direct switch for cleaner signal travel from pre-amp direct to power amp.

Two tape deck capability with tape copy either way.

MIC mixing with any source.

Connections for two pairs of speakers.

Specifications

Power output: 55 + 55 watts into 8 ohms

Total harmonic distortion: 0.05%

Rise time: 1.4 μS

Slew rate: ±70 V/μS

Intermodulation distortion: 0,009% (at rated power)

Damping factor: 45 (20Hz-20kHz)

Frequency response: 2 Hz to 250 kHz

Speaker impedance: 4 to 16 ohms

Input sensitivity:

Phono MM: 5.0mV(Max. input 210mV)

Tuner, Aux, Tape: 150mV

Signal to noise ratio:

Phono MM: 83 dB

Tuner, Aux,Tape: 105 dB

Phono Frequency Response: ±0,4 dB (RIAA curve)

Dimensions (WxHxD): 400 x 139 x 296 mm (15¾ x 5¹⁵⁄₃₂ x 11²¹⁄₃₂ in)

Weight: 7.6kg (16,8 lbs)


Galactron MK 120 (1975)

Nel 1966 nasceva una delle più importanti ditte italiane costruttrici di apparecchiature per "alta fedelta" - Galactron. Nata a Roma sopratutto per iniziativa di alcuni appassionati come Bernardi, Lojodice, Marietti, Finocchiaro e Zampa.

Il MK 120 fu il primo integrato, dopo MK 10, realizzato dalla Galactron nel 1975, che riprendeva le funzionalità e lo stile dell MK 16 e MK 160, ed è stato progettato per il audiofilo meno esigente.

Nel 1976 ottiene il terzo posto nel concorso Gold Sim a Milano, ma il primo fu assegnato al sintonizatore Galactron ST 101 della stessa serie.

Oltre ad una estetica elegante ed innovativa per il epoca, MK 120 è dotato di caratteristiche tecniche molto interessanti. Il primo elemento che richiama l'attenzione è la serigrafia sul panello frontale dello schema a blocchi dell'amplificatore, che ilustra il passaggio del segnale dall'ingresso alla uscita dell'amplificatore.

Dal disegno è possibile rilevare la posizione circuitale dei controlli di livello e del master-volume e stabilire le condizioni che consentono di ottenere i migliori risultati di rapporto segnale/rumore. Agendo sui due controlli posti subito dopo gli ingressi è possibile regolare il livello inviato agli stadi successivi , unLED verde indica quando è sufficiente. Il segnale attraversa poi i circuiti dei controlli di tono e dei filtri e qui un secondo LED in questo caso rosso, si accende quando viene raggiunto unlivello prossimo al sovraccarico degli stadi che seguono; a questo punto agendo sul master-volume posto al'uscita dello stadio preamplificatore si può controllare il segnale inviato allo stadio finale. Con il LED rosso ad inizio accensione ed il master al massimo si ottiene la massima potenza di uscita indistorta.

Il MK 120 è dotato di sette ingressi selezionabili, di cui due per il Tape ed uno per il Phono tipo MM, è da notare che l'ingrsso "Special" può essere adattato sia per segnali ad alto livello sia per testine magnetiche oppure microfono, l'optional che lo consente, utilizzabile anche con gli altri apparecchi Galactron, come MK 10 e MK 16, è la scheda modello 373 che può essere utilizzata come preamplificatore/equalizzatore secondo lo standard RIAA o come preamplificatore lineare per l'ingresso microfono. La selezione oltre a quella della sensibilità desiderata, viene effetuata tramite una microtastiera montata sul circuito, che in fabbrica vienne predisposta per sensibilità 1 mV e equalizzazione RIAA. I controlli di tono, separati per i due canali, agiscono con diverse frequenze di intervento ma non possono essere considerati dei controlli multifrequenze. Il solo filtro passa-banda è quello a 1,000 Hz che consente una regolazione di ±6 dB, gli altri agiscono come dei normali controlli di tono con frequenze di intervento indicate di 40 Hz (±6 dB), 100 Hz (±10 dB), 10 kHz (±10 dB) e 20 kHz (±6 dB); gli slider consentono una regolazione graduale corrispondente alla scala.

Tra le diverse possibilita di impostazione è molto comodo trovare il tasto "flat" che disinserisce i controlli di tono. Per dare un idea della potenza erogata dall'amplificatore e per controllare il equlibrio tra i canali sono comodi due "power-meter" .

Il selettore degli ingressi è a pulsantiera e non premendo nessuno dei tasti viene selezionato l'ingresso phono. Per i due registratori collegabili è prevista la possibiltà di "copia" delle registrazioni in entrambi i sensi con possibilta di ascoltare il segnale proveniente da qualsiasi ingresso durante la duplicazione. le prese per gli ingressi sono a norma americana tranne le duplicazioni con presa pentapolare DIN degli ingressi phono e tape 1.

MK 120 può pilotare due coppie di diffusori, contemporaneamente se di impedenza pari o superiore di 8 ohm. collegando gli ai morsetti posti sul panello posteriore contrassegnati con la lettera A il canale sinistro e con la B quello destro.

La realizzazione dell'amplificatore è molto curata, moderna e tecnologicamente avanzata con largo uso di integrati. I componenti sono montati su circuiti stampati estraibili per facilitare eventuali operazioni di assistenza. L'impostazione circuitale del finale è ad alimentazione bilanciata e stadio di potenza a simmetria complementare con accoppiamento diretto al carico senza condensatore d'uscita. MK 120 è dotato di una protezione elettronica sia dei finali sia dei diffusori che fa uso di un relè, l'intervento viene segnalato dall'accensione di un LED giallo.

Il circuito preamplificatore/equalizzatore dell'ingresso phono RIAA utilizza un circuito integrato F739PC selezionato in fabrica per ottenere il migliore rapporto segnale/rumore. All'ingresso dello stadio finale un filtro passivo limita la banda passante del preamplificatore per prevenire l'insorgere di fenomeni di instabilità nei transienti che potrebbero influenzare la timbrica.

Opinioni e voti secondo la rivista "Stereoplay" n. 41

Estetica: 9

Molto personale, si richiama al noto stile del preamplificatore MK 16 del quale conserva alcune caratteristiche tecnice e di utilizzazione.

Controlli e versatilià: 9

La già notevole versatilità può essere ulteriormente aumentata con l'acquisto della scheda preamplificatrice modello 373; i controlli sono posizionati in modo molto razionale per una facile individuazione ed una comoda utilizzazione.

Costruzione: 8

Realizzazione molto accurata secondo le tecniche più avanzate; notevole uso di schede e gruppi estraibili che semplificano eventuali operazioni di assistenza o di riparazione.

Prestazioni: 9

I dati rilevati in laboratorio hanno superato le specifiche fornite dal costruttore confermando l'elevato standard produttivo Galactron

Suono: 8

La potenza superiore al 70 watt su 8 ohm ed ai 100 watt su 4 ohm permette un funzionamento corretto nella quasi totalità delle applicazioni domestiche. le prestazioni ed i controlli dell'MK 120 sono tali da ottimizzare la timbrica di qualsiasi impianto e la prova d'ascolto lo ha confermato.

Prezzo: 9

Buono il rapporto qualità/prezzo sia per le prestazioni sia per la versatilità; positiva l'assistenza diretta del costruttore.

Caratteristiche tecniche

Potenza massima: 70 + 70 watt su 8 Ω; 100 + 100 watt su 4 Ω (a 1kHz con due canali funzionanti)

Distorsione armonica totale: <0,015% a 75 watt (1 kHz)

Distorsione da intermodulazione: 0,36% a 70 watt (50/7000 Hz, 4:1 SMPTE)

Risposta in frequenza: 20 - 20,000 Hz ±1 dB (a 1 watt)

Equalizzazione ingresso phono RIAA: 20 - 20,000 Hz ±0,4 dB

Fattore di smorzamento (8 ohm): 100 Hz, 1 kHz, 10 kHz = 50

Sensibilita massima ingresso Phono: 1,25 mV

Sensibilita massima ingressi: 170 mV

Rapporto S/N ingresso Phono: 69/75 dB (sinistro/destro)

Rapporto S/N ingressi: 86,5/90,5 bD (sinistro/destro)

Uscita tape ingresso nominale su 100 kohm: 170 mV (pin Jack); 26,5 mV (DIN)

Filtri:

Bassi : -1 dB a 50 Hz

Alti : -9 dB a 10 kHz

Alimentazioe: 220 Volt, 50/60 Hz

Dimensioni: 240 x 460 x 220 mm

Thorens TD 535 (1989)

Thorens knows how to bulid high quality turntables meeting the specific needs of every user, and in fact since the existance of records.

Flability and long term maintenance of the original characteristics rank first in the company's rules.

The new TD-535 professional transcroption turntable has been developed by Thorens exactly in this way, for broadcasting studios and discotheques.

Shortest run-up time

A direct drive motor of European make, improved according to Thorens specifications and controlled by a costly electronic circuit, accelerates the zino-aluminium turntable platter to reach the 33 rpm speed in less than 0,5 second. This exceptional value is exceeded only by the more expensive TD524 model, also manufactured by Thorens. The motor has a high torque so that slip-mats or record cleaning devices with dragging action can be used without problem. The nominal speed is quarz controlled.

Anti-feedback suspension

The low frequency sound waves loved by Disco fans, generally cause serious feedback problems in discotheques. Not so with TD-535. A new, genial floating chassis suspension is combined with the fast starting direct drive system in such a way that the suspended chassis remains free of rotational vibrations during the acceleration process. The Thorens floating chassis suspension isolates the platter - tones arm assembly from external footfall and low frequency sound waves. This association of a direct drive system with a floating chassis suspension is unique and helps solving all location problems in discotheques and broadcasting studios.

Vario Control

An easily accessible sliding pitch control permits a ±15% variation of the nominal speed. An important feature for discotheques and dancing schools.

Heavy duty, high quality TP 90 tone arm

For optimum in tracking ability it is not sufficient that a tone arm has a low bearing friction. It is much more important that it has a low effective mass, because high mass prevents the stylus from following the imperfections (warp or ripple) of the record as it should do. Precision bearings are used in this professional arm, making it insensitive to shock and rough handling. A high precision screw-coupling offers the facility of a plug-in shell without adding any imperfections to the resonance characteristics of the tone arm.

The TP90 has been designed in such a way that none of its elements produce any perturbing self-resonances. Such resonances alter the sound quality and modify the timbre of the instruments. In addition to the optimization of all components, the tone arm as a whole has been harmonized for a great robustness and a total sound neutrality. it will match ideally with almost every cartridge.

Quality and durability

High quality and long term stability characterize all Thorens products. Since over 105 years, Thorens has been manufacturing high value, reliable instruments for the reproduction of music. The technical data published are quaranteed values and they are maintained even after years of intensive use.

Should replacement parts become necessary, Thorens holds stocks of spare parts for a minimum of 10 years and in most casses for 20 years and over.

Specifications

Drive system: servo-controlled DC motor

Speeds: 33; 45; 78 rpm, quarz controlled

Pitch control: ±15% with sliding control

Run-up time: 400 ms

Turntable platter: zinc/aluminium alloy

Turntable mat: rubber or felt

Rumble: -52 dB acc. to DIN 45539

Wow and flutter: 0,04% acc. to DIN 45507

TP 90 Tone Arm

Plug-in shell TP95

Effective length: 228 mm

Effective mass: 15 g

Stylus overhang: 18 mm adjustable

Offset angle: 24°

Lateral tracking error: ≤ 0,16°/cm of radius

Skating-compensation: frictionless magnetic assembly

Bearing friction: ≤ 0,15 mN (15 mp) in both planes

Cartridge mouting: Standard ½"

Capacitance of cable: 120 pF

Dimensions (WxHxD): 450 x 360 x 100 mm

Weight: 12 kg

Acoustic Research AR 11 (1977)

The AR-11 is the most accurate speaker system ever made by Acoustic Research. Its performance, drivers, and crossover are identical to those of the AR-10π, except that the Ar-11 does not incorporate a Woofer Environmental Control and the associated crossover components. The AR-11 is designed for optimum performance when placed against a wall, as on a bookshelf, or slightly away from two room surfaces, as illustrated.

The AR-11 uses a substantially improved version of the 305 mm (12 in) woofer with which Acoustic research introduced the acoustic suspension principle to home listeners, as well as the hemispherical dome midrange of the AR-3a. It also uses a newly designed 19 mm (3/4 in) highrange based on the original high-frequency dome radiator introduced by Acoustic Research in 1959. This highrange driver incorporates new diaphragm materials, voice coil, and construction techniques that have produced significant improvements in performance over earlier versions. it has a lower resonance frequency and more extended high-frequency response, plus greater efficiency and higher available output.

These drivers are used with a new crossover network to produce a speaker system with uniformly dispersed flat energy output to the highest audible frequencies. It is able to transmit the information from a program source to listeners in most locations in a room with an unprecedented degree of accuracy.

A pair of three-position switches provide a means of decreasing the overall level of the midrange and highrange drivers in 3 dB steps. The "0" position of the switches should provide the most listening rooms, while the "-3 dB" and "-6 dB" settings are useful for compensating for the effects of more reverberant, or "live" rooms.

The AR-11 shares many of the appearance features of the AR-10π, including an easily removable precision-machined foam grill, which was chosen for its near-perfect acoustical transparency.

Specifications

Drive units:

Woofer: acoustic suspension 305 mm (12 in)

Midrange; hemispherical dome 38 mm (1½ in)

Highrange: hemispherical dome 19 mm (¾ in)

Crossover frequencies: 525 Hz, 5000 Hz

Impedance: 4 Ω nominal

Efficiency: 86 dB 1W/1m

Controls: two 3-position switches for midrange and highrange level control

Driver resonance frequencies:

Woofer: 18 Hz (free air)

Midrange: 400 Hz

Highrange: 2000 Hz

System resonance frequency: 42 Hz

Effecive system Q: 0,7

Total flux:

Woofer: 200,000 maxwells

Midrange: 70,000 maxwells

Highrange: 21,000 maxwells

Flux density:

Woofer: 9,800 gauss

Midrange: 13,000 gauss

Highrange: 14,000 gauss

Crossower network:

Half-section LC network on each driver using air-core chokes and computer grade electrolytic capacitors, acoustic output of midrange and highrange driver is controlled by switchable resistive networks.

Power requirement:

Minimum 25 watts per channel for an averge room, to obtain a closer approx. of the minimum power required, in continous RMS watts per channel for the realistic reproduction of musical sound levels in a perticular room, divide the volume of the listening room, measured in cube feet by 100; 25 watts (into one speaker only) will produce 100 dB SPL in a 3000 cu ft room of average reflectivity (energy absorption coefficient of 0,15); 50 watts (25 watts per channel) will produce 103 dB SPL in the same room

Power-handling ability:

Maybe used with amplifiers capable of delivering up to 150 watts continuous power per channel being driven to clipping 10% of the time, on normal music source material

Volume of enclosure: 41,9 liters (1,48 cu ft)

Dimensions (W x H x D): 354 x 635 x 273 mm (13 x 25 x 10¾ in)

Weight: 2,6 kg (49¾ lb) unpacked