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





Technics SL-1100AC

 Technics SL-1100 AC Direct Drive Turntable

The SL-1100AC provides that incomparable professional technics quality in a reasonably priced package. The heart of this outstanding direct drive turntable is its DC brushless motor which drives the platter directly to eliminate belts, pulleys, and idlers. This simple design means fewer moving parts to wear out and greater long term reliability. The motor is controlled electronically by a DC servo which provides highly accurate rotation completely unaffected by power line frequency and voltage variations.
 And due to its high torque, speed remains the same even during changes of external drag. This combination produces wow & flutter of  0,03% (WRMS) and rumble of better than -70 dB (DIN B).
The turntable is dynamically balanced and of extra large size (35 cm/13-25/32") and weight (2 kg/4,4lb.) to contribute to overall high performance.
 The tonearm is static balanced low mass tubular with a length  (pivot to stylus) of 235 mm (9¼") for to tracking error. Effective arm mass has been kept very low to accommodate high compliance cartridges.  The headshell is made of precision diecast aluminum with the universal type connector.
 Other features include independent pitch controls variable ±5%, illuminated stroboscope, feather-touch start/stop buttons, viscous-damped cueing, anti-skating device, feedback insulated legs, diecast aluminum base, detachable dust cover, and two AC outlets (one for stroboscope).

Technics SL-110A
Identical in every respect with model SL-1100AC, but without tonearm. Metal tonearm panel permits installation of any tonearm. Transparent dust cover supplied.
SH-11P3

Arm panel for SME arm


 Specifications SL-1100AC
Turntable Section
Type:  Direct drive turntable
Motor:  20-poles (rotor), 15-poles (stator), ultra-low-speed DC brushless motor
Turntable Material:  Dynamically-balanced aluminum diecast
Diameter:  350 mm (13-25/32")
Weight:  2 kg (4,4 lb)
Inertial Moment:  7,7 kg/cm²  (109,5 lb/in²)
Turntable Speeds:  33-1/3 and 45 rpm
Speed Change Method: Electronic change
Variable Pitch Controls:  Individual adjustment by variable resistor,  ±5% adjustment range
Wow and Flutter : Less than 0,03% WRMS
Rumble:  Better than -50 dB (DIN A);  -70 dB (DIN B)
Build-up Time:  Within ½ rotation at 33-1/3 rpm
Tonearm Section
Type:  Static-balanced tubular
Effective Arm lenght:  230 mm (9-1/16")
Overhang:  14 mm (35/64")
Cueing Control:  viscous-damped
Tracking Force Control:  0 -5 g direct reading type
Tracking Error Angle:  Within ±1,75°
Anti-skating Device:  Yes
Cartridge Headshell:  Universal type
General
Power Supply:  AC 120 V - 240 V, 50/60 Hz
Power Consumption:  4 W
Player Base:  Aluminum diecast with audio insulated legs 
Dimensions (H x W x D):  195 x 510 x 390 mm ( 7-11/16" x 20-3/32" x 15-3/8")
Weight:  13 kg  (28,7 lb)


Technics Direct Drive Turntable Technology

Technics SL-1600

 Technics SL-1600 Direct Drive Fully Automatic Turntable

The SL-1600 features fully automatic play while incorporating the famous technics direct drive motor  and B.FG Servo One Chip IC control System.  The auto-mechanism permits auto start, auto retur, and auto stop, and will automatically repeat a record up to six times or indefinitely when the Memo-Repeat dial is set. A simple flick of the auto start lever automatically lifts the arm from the rest, places it on the record, returns it to the arm rest at the end of play, and shuts off the turntable.  Should you wish to stop play in the middle of a record, simply slide the lever to the stop position and the arm will automatically lift and return to the arm rest and the power will ashut off. With this handy automatic feature, The SL-1600 brings you the maximum in operating convenience with no compromise in turntable performance. 
 The motor of the SL-1600 is the incomparable Technics direct drive brushless DC motor which contains only one moving part, the rotor, which is also the platter. For motor drive and control this turntable employs our famous One Chip IC which is equivalent to 321 separate electronic components.  A B.FG (back-Electromotive-Force Frequency Generator) servo control reglates the speed and issues instant correction commands whenever necessary. The result; a spectacular wow & flutter of0,025% (WRMS), an inaudibly low rumble of -73 dB (DIN B).
 Rapid atarting time,full speed within 1/3 rotation of a turn and 0% speed variation up to 30 g tracking force. A number of measures are taken in the SL-1600 to isolate the motor, platter and tonearm from outside vibrations. The Floating Double Isolator insulates these important parts from most vibrations transmitted through the floor or the air.
 A heavy, aluminum diecast base, a heavy zinc tonearm base, a newly designed turntable mat, and precision made diecast aluminum cabinet also act to absorb vibrations and keep them away from the record platter and the tonearm. And speaking of the tonearm, it is gimbal suspended to ensure 7 mg friction. Effective arm mass has been kept very low (22 g) to accomodate premium high compliance cartridges. Other features include illuminated stroboscope, fine-scaled anti-skating device, independent pitch controls variable by up to 10%, viscous-damped cueing device and detachable dust cover.

Specifications SL-1600
Turntable Section
Type:  Direct drive fully-automatic turntable
Motor:  Electronically controlled brushless DC motor
Turntable Platter:  Aluminum diecast , 330 mm (13") diameter
Turntable Speeds:  33-1/3 and 45 rpm
Speed Change Method: Electronic change
Variable Pitch Controls:  Individual adjustment controls,  10% adjustment range
Wow and Flutter : 0,025% WRMS (JIS C5521) ±0,035% weighted, zero to peak (DIN 45507)
Rumble:  -50 dB (DIN 45539 A);  -73 dB (DIN 45539B)
Tonearm Section
Type:  Universal S-shaped tubular arm, static-balanced type, direct-reading tracking force adjustment, with anti-skating force control device, oil-damped cueing device
Effective Arm lenght:  230 mm (9-1/16")
Overhang:  15 mm (19/32")
Friction:  7 mg (horizontally and vertically)
Effective Mass:  22 g (6,0 g cartridge weight, 1,75 g stylus pressure)
Tracking Error Angle:  Within +3° (at the point of 14,5 cm or 5-45/64" record);  +1° (at the point of 5,5 cm or 3-2/16" from the centre)
Offset Angle:  21,5°
Adjustable Tracking Force:  0 - 3 g (direct-reading)
Cartridge Range:  5 - 11 g
Headshell Weight:  9,5 g
General
Power Supply:  AC 120 V - 240 V, 50/60 Hz
Power Consumption:  5 W
Dimensions (H x W x D):  125 x 453 x 369 mm ( 4-15/16" x 17-12/16" x 14-9/16")
Weight:  9 kg  (19,8 lb)


Technics Direct Drive Turntable Technology

Technics SL-1700

 Technics SL-1700 Direct Drive Semi-Automatic Turntable

The SL-1700 offers the famous Technics direct drive system with the added convenience of semi-automatic operation. Once the tonearm is manually positioned over the lead-in grooves, the automatic mechanism will lower the tonearm onto the record when the lever is flicked, and automatically return it to the arm rest at the complteion of play. The  unit is then automatically shut off. This handy feature frees the user from rushing to the turntable at the end of record play and also saves wear on your stylus.   At any time during play, flicking the stop lever will cause the tonearm to automatically lift up and return to the arm rest.
  To control the DC direct drive motor, the Sl-1700 incorporates a B.FG servo with One Chip IC which can perform the functions of up to 321 transistors, diodes and resistors. B.FG stands for Back-Electromotive-Force Frequency Generator and it desribes the method whereby the back electromotive force induced by the rotor in the stator coils is used to monitor the speed of the platter. The waveform obtained from this becomes the reference for the frequency generator. Its output is compared with the standard calibration frequency obtained from the reference oscillator and then, when needed, a correction signal instantly changes the motor drive current to the proper value to turn the platter at precisely the right speed. Wow & flutter for the SL-1700 is an insignificant 0,025% (WRMS), while rumble is -73 dB (DIN B).

 The SL-1700 also is equipped with Technics newly designed Floating Double Isolator, which prevents acoustic feedback by shielding the turntable and tonearm assembly from external vibrations. This isolator actually insulates the turntable from the outside with two layers of specially designed isolators constructed of metal springs and special vibration absorbing material.
 The SL-1700 is equipped with several other defences against acoustic feedback; a heavy zinc alloy tonearm base, a newly designed turntable mat, and a precision made diecast aluminum cabinet. The tonearm is gimbal suspended to achieve 7 mg friction. Effective arm mass has been kept very low (22 g) to accommodate premium high compliance cartridges.
Other features of the Sl-1700 include a fine-scale direct reading anti-skating control, illuminated stroboscope, independent pitch controls variable by up to 10%, viscous-damped cueing device, and detachable dust cover.
Specifications SL-1700
Turntable Section
Type:  Direct drive semi-automatic turntable
Motor:  Electronically controlled brushless DC motor
Turntable Platter:  Aluminum diecast , 330 mm (13") diameter
Turntable Speeds:  33-1/3 and 45 rpm
Speed Change Method:  Electronic change
Variable Pitch Controls:  Individual adjustment controls,  10% adjustment range
Wow and Flutter : 0,025% WRMS (JIS C5521) ±0,035% weighted, zero to peak (DIN 45507)
Rumble:  -50 dB (DIN 45539 A);  -73 dB (DIN 45539B)
Tonearm Section
Type:  Universal S-shaped tubular arm, static-balanced type, direct-reading tracking force adjustment, with anti-skating force control device, oil-damped cueing device
Effective Arm lenght:  230 mm (9-1/16")
Overhang:  15 mm (19/32")
Friction:  7 mg (horizontally and vertically)
Effective Mass:  22 g (6,0 g cartridge weight, 1,75 g stylus pressure)
Tracking Error Angle:  Within +3° (at the point of 14,5 cm or 5-45/64" record);  +1° (at the point of 5,5 cm or 3-2/16" from the centre)
Offset Angle:  21,5°
Adjustable Tracking Force:  0 - 3 g (direct-reading)
Cartridge Range:  5 - 11 g
Headshell Weight:  9,5 g
General
Power Supply:  AC 120 V - 240 V, 50/60 Hz
Power Consumption:  6 W
Dimensions (H x W x D):  125 x 453 x 369 mm ( 4-15/16" x 17-12/16" x 14-9/16")
Weight:  8,8 kg  (19,4 lb)


Technics Direct Drive Turntable Technology

Technics SL-1800

 Technics SL-1800 Direct Drive Turntable

The SL-1800 features full Technics uncompromised direct drive performance in a simple, straightforward package. The centre ofthis sleek,attractive unit is its highly accurate One Chip IC controlled B.FG servo DC motor. This direct drive motor, which incorporates all of the design features of all Technics fine dd motors, is controlled by the unique B.FG (Back-Electromotive-Force Frequency Generator) system which utilizes the back electromotive force induced by the rotor in the stator field coils to monitor yhe platter speed. The frequency generator uses the waveform obtained as its reference and it is compared with the standard calibration frequency from the reference oscillator. In this way , a signal to correct the speed can be sent instantly whenever needed to change the motor drive current in order to maintain precise platter speed.

 This B.FG principle greatly improves speed stability and gives a shorter build-up time. It also maintains the platter speed under varying oad conditions. The above mentioned control circuitry is all contained in a fantastic One Chip IC which can perform the functions of up to 321 separate elements such as transistors, diodes and resistors. The sum of all this electronic and mechanical advancement is performance, the kind of super performance that produces the low wow and flutter figure for SL-1800 of only 0,025% (WRMS), a figure almost unsurpassed by any other turntable anywhere. Rumble is -73 dB (DIN B). Another outstanding feature of the SL-1800 is the Floating Double Isolator. This new advance fights against acoustic feedback by shielding the turntable and tonearm assembly from all outside vibrations with two separate isolators constructerd of metal springs and special vibration absorbing material.
 Additional features of the SL-1800 are a fine-scale direct reading anti-skating device, an illuminated stroboscope, independent pitch controls variable by up to 10%, sensitive gimbal suspension tonearm, viscous-damping cue arm, and detachable dust cover.
Specifications SL-1800
Turntable Section
Type:  Direct drive turntable, manual
Motor:  Electronically controlled brushless DC motor
Turntable Platter:  Aluminum diecast , 330 mm (13") diameter
Turntable Speeds:  33-1/3 and 45 rpm
Speed Change Method: Electronic change
Variable Pitch Controls:  Individual adjustment controls,  10% adjustment range
Wow and Flutter : 0,025% WRMS (JIS C5521) ±0,035% weighted, zero to peak (DIN 45507)
Rumble:  -50 dB (DIN 45539 A);  -73 dB (DIN 45539B)
Tonearm Section
Type:  Universal S-shaped tubular arm, static-balanced type, direct-reading tracking force adjustment, with anti-skating force control device, oil-damped cueing device
Effective Arm lenght:  230 mm (9-1/16")
Overhang:  15 mm (19/32")
Friction:  7 mg (horizontally and vertically)
Effective Mass:  22 g (6,0 g cartridge weight, 1,75 g stylus pressure)
Tracking Error Angle:  Within +3° (at the point of 14,5 cm or 5-45/64" record);  +1° (at the point of 5,5 cm or 3-2/16" from the centre)
Offset Angle:  21,5°
Adjustable Tracking Force:  0 - 3 g (direct-reading)
Cartridge Range:  5 - 11 g
Headshell Weight:  9,5 g
General
Power Supply:  AC 120 V - 240 V, 50/60 Hz
Power Consumption:  5 W
Dimensions (H x W x D):  125 x 453 x 369 mm ( 4-15/16" x 17-12/16" x 14-9/16")
Weight:  8,5 kg  (18,7 lb)

Technics Direct Drive Turntable Technology

Technics SL-2000 DD

Technics SL-2000 "Black Beauty" Direct Drive Turntable

 The SL-2000 is designed for those who want direct drive performance at a moderate cost. This beauty is equipped with Technics famous brushless DC motor, which operates free from power line fluctuactions and trouble causing heat and hum. The absence of moving parts in the motor means better reliability and longer service life. Completely accurate platter speed is quaranteed by a One Chip IC servo control, a simple and compact unit equivalent to 78 electronic components. The result of all this precision is wow & flutter of only 0,045% (WRMS) and rumble 0f -70 dB (DIN B).
 A precisely manufactured tonearm ensures minimum tracking error and optimium mass distribution for high compliance cartridges. Clear and clean sound reproduction is assisted by the Insulation Fibre Board (IFB) and a newly developed insulator which effectively shields the motor and tonearm assembly from outside vibrations. The heavy zinc diecast tonearm base also works to prevent vibration and subsonic resonances.
 Other features include a fine-scale (increments of 2,5g) direct reading antiskating device, an illuminated stroboscope, independent pitch controls variable by up to 10%, viscous-damped cueing, aluminum diecast universal headshell, and detachable dust cover.
Specifications  SL-2000

Turntable Section
Type:  Direct drive turntable
Motor:  Low-speed electronically controlled brushless DC motor
Turntable Platter:  Aluminum diecast , 300 mm (12") diameter with strobe
Turntable Speeds:  33-1/3 and 45 rpm
Speed Change Method: Electronic change
Variable Pitch Controls:  Individual adjustment controls,  10% adjustment range
Wow and Flutter : 0,045% WRMS (JIS C5521) ±0,065% weighted, zero to peak (DIN 45507)
Rumble:  -47 dB (DIN 45539 A);  -70 dB (DIN 45539B)
Tonearm Section
Type:  Universal S-shaped tubular arm, static-balanced type, direct-reading tracking force adjustment, with anti-skating force control device, oil-damped cueing device
Effective Arm lenght:  222 mm (8-21/32")
Overhang:  14 mm (35/64")
Tracking Error Angle:  Within +3° (at edge of 30 cm or 12" record);  -0,2° (at centre of 30 cm or 12" record)
Offset Angle:  22°
Adjustable Tracking Force:  0 - 3 g (direct-reading)
Cartridge Range:  3,5 - 9 g
Headshell Weight:  9,5 g
General
Power Supply:  AC 120 V - 240 V, 50/60 Hz
Power Consumption:  3,5 W
Dimensions (H x W x D):  125 x 430 x 346 mm ( 4-15/16" x 16-15/16" x 13-5/8")
Weight:  6,1 kg  (13,4 lb)

Technics Direct Drive Turntable

 Direct Drive; The Idea That Revolutionized the Turntable

When Technics first introduced the direct drive turntable back in 1969, we were sure that our new drive design would revolutionize turntable manufacre. Subsequent history has shown that we were correct. The direct drive system was so much of an improvement oer the old way that it just couldn't be ignored, and the rest of the audio world was quick to imitate us. Today the direct drive turntable has become the industry standard, and it's no wonder. Just take a look at the direct drive advantages.

Greater Simplicity
In the Technics integral rotor-platterstructure direct drive system, the platter serves as the rotor and the motor housing serves as the stator. Thus, the plater is the only moving part. No pulleys, no belts, and no idlers are needed to drive the platter. Construction is greatly simplified and overall precision is much greater. And with fewer parts to wear out, reliability and service life is vastly improved.

Greater Efficiency
The direct drive motor runs at an ultra-slow speed since it need rotate no faster than the platter. This reduces mechanical wear and stress, causes less evaporation. The brushless DC motor has a power consumption 90% lower than conventional motors. This means much less trouble causing heat and lengthened service life of all parts. And the elimination of the Ac motor means the elimination of hum and power line frequency variations as a source of speed inaccuracy.
Higher Performance
The real payoff is in performance. The simple construction of the direct drive system enables much more precise construction and easier quality control. This has permitted the reduction of wow and flutter to spectacularly low levels and the total elimination of rumble as a source of interference. As you can, see it is no exaggeration to say that the technics direct drive turntable has revolutionized the world of turntables. 

Double Isolated Suspension System
As they have done in so many oyher areas of turntable design, Technics engineers have come up with an ingenious and unique method of coping with the acoustic feedback problem; the floating double isolator. External sounds and vibrations that reach the turntable either through the air or throught the unit's resting position - are met by two separate isolation systems. The first isolators effectively dampen harmful external vibrations which may reach the unit through the surface that it rsts on. The all important turntable, motor and tonearm assembly are then supported on a main base which floats on the secondary isolation system. These isolators are specially designed with material and springs of calculated and finely tuned elasticity to absorb external vibrations. The result is an audible clearity and transparency in sound.
Gimbal Suspension Tonearm
For the finst tracing senstivity, Technics tonearms rest in a gimbal suspension equipped with two pairs of low friction pivot bearings. With this enhanced rotational sensitivity, the tonearm is allowed free, gyroscopic movement to ensure flawless tracking.
One Chip IC Control

Most Technics direct drive turntables incorporate sophisticated one chip interated circuits to govern all motor control funtions. This One Chip IC is one of teh secrets behind the spectacular performance achieved by Technics DD unit. The B.FG principle (Back-Electromotive-Force Frequency Generator) causes a near instantaneous current change to correct for even the slightest speed deviation, assuring highly stable rotation.

 Quartz Phase-Locked Servo Control
The quartz oscillator, the most accurate method known for electronic frequency control, is used in Technics professional grade turntables to provide the basic reference frequency for all motor movements and for the stroboscope. This allows the achievement of the fantastically low speed drift figure of ±0,002%, or a maximum of ±0,036 second error over the 30 minute playing time of a typical LP side.

High Starting and Running Torque
Due to exceptionally high motor torque (6 kg-cm), speed built-up is an amazing 0,25 second. Normal operating speed (33 rpm) is reached after only a 25 degree turn of the platter.

Anti-Skating Device
For perfect tracking, a fine-scale anti-skating device permits adjustment to fit all stylus pressures.

Independent Variable Pitch Controls
To allow adjustment of the rotatiopnal speed, independent pitch controls are built-in.

Illuminated Stroboscope
permits monitoring of exact platter speed

Universal Headshell
For convenient replacement of cartridge, a removable universal headshell fits easily onthe end of the tonearm.

Viscous-Damped Cueing
This feature is provided even on automatic units to allow safe manual lowering of the tonearm onto the record.

Detachable Dust Cover and Sleek, Elegant Design



Technics Direct Drive Turntables:
Technics SL-2000
Technics SL-1800
Technics SL-1700
Technics SL-1600
Technics SL-1100
Technics SP-10 MkII

Kenwood KA-1500

 The fine quality of this integrated stereo amplifier has been achieved by the application of some of the most advanced technology known in the audio field. Total harmonic distortion, for example, is under 0,1% at full rated output. And ezch channel delivers a full 25 watts throughout the audio spectrum - from 20 to 20,000 Hz at 8 ohms - for rich, clean sound. Dynamic music power reaches 100 watts but for those who love music, quality comes first, and for crystal-clear room-filling beautiful sound, the KA-1500 has few rivals.
 High Power  and Low Distortion
Using fully complementary circuitry that's direct-coupled throughout, the KA-1500 delivers its power with a THD that is under 0,1% at all frequencies from 20-20,000 Hz. The high quality of sound achieved is evident not only at first hearing but also in the absence of "listening fatigue" after many hours of enjoyable music listening. Kenwood's non-compromise approach to designing has assured the high power and low distortion which characterizes the most expensive audio equipment.

Ideal for listening to the finest stereo records
With the high quality of modern stereo records, Kenwood engineers gave high priority to excellent record reproduction. The result is that the KA-1500 reproduces the RIAA curve that all record manufactures use with accuracy that is absolute to within ±0,5 dB. In addition, there is the same kind of high overload capacity that is ordinarily associated with the very finest audio components. This means no distortion even with high level orchestral climaxes.

Top  performance under demanding conditions
Long nonstop operation, changes in temperature and humidity are factors that can seriously affect performance. But KA-1500 has special features to perform beautifully at all times. Advanced, high-efficiency heat sinks, special heat compensation devices, and massive twin capacitors to stabilize the power supply are only a few of the many notables.
 Facilities for two tape decks and dubbing
This advanced feature lets you record simultaneously on two tape decks. It also allows you to copy from one tape deck onto another.

Hi-Fi listening at night
The new loudness control compensates for the loss of fidelity that results at low volume listening. As a result, you can enjoy all the excitement of stereo with full fidelity.

Flexible and accurate tone controls
The KA-1500's new tone controls allow you to adjust the sound as you like it. You can increase or decrease the bass and treble independently to match the sound characteristics of your room and to get the very best out of your speakers.

Extra-large 41 clik stop volume control
The extra-large volume control knob means you can easily make fine adjustments to perfectly achieve the perticular level you prefer. The marked positions allow quick relocation of any previous setting.

Kenwood's famous "human engineering"
You will discover that all controls have been carefully placed for easy operation and designed for positive, instant action. The KA-1500 not only operates and looks like an excellent audio component, it also "feels" like the outstanding amplifier that it is.
Specifications
Power Output:  25 watts per channel, min. RMS at 8 Ω, 20 Hz to 20 kHz, with no more than 0,1% THD.
Both Channel Driven:
29 + 29 watts at 8 Ω (1 kHz)
36 + 36 watts at 4 Ω (1 kHz)
Dynamic Power Output:  100 watts at 4 Ω
Total Harmonic Distortion:  0.1% at rated power into 8Ω; 0,05% at 1 watt into 8 Ω
IM Distortion (60 Hz : 7 kHz = 4 :1):  0.05% at rated power into 8Ω; 0,05% at 1 watt into 8 ohm
Power Bandwidth:  20 Hz at 35,000 Hz
Damping Factor:  30 at 8Ω
Speaker impedance:  4Ω to 16Ω
Preamplifier Section
Input Sensitivity/Impedance:
Phono : 2.5 mV/50 kΩ
Tuner: 160 mV/50 kΩ
Tape , Aux: 160 mV/50 kΩ
Signal to Noise Ratio:
Phono :  70 dB 
Tuner, AUX, Tape : 90 dB 
Maximum Input Level Phono:  150 mV (at 1 kHz, 0,1% THD)
Outpuut Level/Imedance (at Phono Position):
Tape REC (PIN) : 160 mV/240 Ω
Tape B (DIN) : 30 mV/39 k Ω
Frequency Response:
Phono:  RIAA standard curve ±0,5 dB
AUX, Tape:  20 Hz to 30 kHz ±1 dB
Tone Control
Bass: ±8 dB at 100 Hz
Treble: ±8 dB at 10 kHz
Loudness Control: 7 dB at 100 Hz (at -30 dB Volume level)
General
Power Requirements: 120 - 240 V, 50/60 Hz
Power Consumption: 250 watts  (full power)
AC Outlet:  1 x Switched, 2 x Unswitched
Dimensions (W x H x D):  380 x 140 x265 mm (14-31/32" x 5-1/2" x 10-17/16")

Weight:  6,7 kg (14,8 lbs) 

Rotel RT-2000

 ROTEL RT-2000 Stereo Quartz PLL AM/FM Tuner
Top performance with a quartz lock system and ideal ease of operation that complements an abundance of information.
In addition to its quartz lock system, the RT-2000 has a front-end with a 5-gang dual-gate MOS FET that guarantees reception sensitivity, and an FM PLL MPX section for superior stereo separation and a wide dynamic range. This model stands on its own in performance and quality.


QUARTZ LOCK
As obvious as it may seem, a tuner's true worth is determined by the accuracy of its tuning. Both of Rotel's 2000 series tuners ensure absolute precision by using a quartz crystal oscillator lock system.
Rotel's quartz lock system automatically compares the precise 10,7 MHz emaneting from the oscillator with the approximate 10,7 MHz of the intermediate frequency (IF). Should there be a discrepancy a positive or negative signal is accordingly emitted by the phase comparator which passes through the low pass filter (LPF) and serves to lock the local oscillator.
Touching the tuning knob unlocks the quartz control. Releasing one's hand from the tuning knob automatically activates the quartz lock circuit which then maintains the station selected. Once tuned stable reception is quaranteed and drift is eliminated regardless of changes oscillation is locked.

FM FRONT END, IF SECTION
Rotel uses a linear-frequency precision 5 gang variable capacitors. The RT-2000 has a 1 Dual-Gate MOS FET stages, both employing the best low-noise components, with resultant superior interference reiection capability as well as having a positive effect on cross modulation interference. The intermediate frequency band is divided into 2 stages, WIDE and NARROW, which ensures superior sound quality under varying conditions of reception, and the linear phase filter aids in low distortion and superior stereo separation.
 AM SECTION
The RT-2000's AM-front -end uses a 16-pin dual-in-line IC package with great resistance to external interference as well as much improved performance. Advanced circuitry means AM broadcasts also become a source for high fidelity sound reproduction.

MULTIPATH INTERFERENCE SUPPRESSION
The multipath phenomenon in FM reception, similar to double images on television , can adversely affect sound fidelity. With the Multipath switch "ON" it is possible to select the optimum position for an antenna. The degree of multipath interference can be checked with the signal meter indicator.

SUPERIOR MPX SECTION
In order to improve frequency characteristics in the MPX section, Rotel has paid particular attention to the cut off of the pilot signal (19 kHz) and weakening of the carrier signal (38 kHz). By using LC block filters, high frequency range drop is minimized and a wide range is guaranteed, with the result that rich sound reproduction is possible. The PLL  IC is employed to assure constant high stereo separation at low distortion for wide dynamic range.

IF BAND SELECTOR
IF (Intermediate Frequency) is the front end output (unified at 10,7 MHz for FM) resulting from the difference between the broadcasting signal received and the oscillator frequency. Rotel makes it possible to select between two options Wide  or Narrow. When reception is weak, use of a narrow IF band can result in superior selection.

DOLBY FM
The RT-2000 incorporates a 25µs de-emphasis switch, in case of a use with an external Dolby NR adapter.

HI BLEND SWITCH
Rotel's Hi-Blend switch creates a faithful and easy-to-listen-to reproduction by cutting out unwanted high frequencynoise with minimum loss for stereo separation and frequency response.
SPECIFICATIONS  ROTEL RT-2000
FM Section:  88 - 108 MHz
Aalternate Channel Selectivity (IHF):  80 dB (narrow)
Frequency Response:  30 Hz - 15 kHz  ±0.2 dB
Stereo separation:  45 dB (1 kHz)
Capture ratio:  1 dB
Image Response Rejection:  100 dB
IF Rejection:  100 dB
Sensitivity (IHF): 
Stereo : 36 dBf/35 µV  (S/N 50dB)
Mono:  9.8 dBf/1.6 µV  (S/N 26dB)
Signal-to-Noise  Ratio (IHF):
Stereo : 75 dB
Mono : 80 dB
Total Harmonic Distortion (wide/narrow):
Stereo : 0,07% / 0.2%
Mono : 0,05% / 0.15%
Muting Threshold:  5 µV
Am Suppresion Ratio:  60 dB
Am Section:  525 - 1605 kHz
Sensitivity (IHF):  200 µV/m
Signal-to-Noise Ratio:  55 dB
Image Rejection:  50 dB
Selectiviy:  40 dB
Dimensions (W x H x D):  482 x 143 x 328 mm

Weight:  7,5 kg

Rotel RE-2000

 Rotel RE-2000 Stereo Octave Equalizer
The component that answers the needs of the most discriminating enthusiast. Essential for maximum flexibility in high fidelity recording and reproduction.
Capable of improving and expanding original sound components and range. Left and right channels independent. Increased fidelity possible by operating the 10 resonant frequency level settings for left and right channels. Class A operation. Discrete resonant circuitry. Less than 0,005% THD. Equipped for tape recorder connection.

Specifications:
Channels:  2 (left, right)
Bands:  10 bands/channel
Bands Control Characteristic:  -12 dB to +12 dB
Center Frequencies:  32, 63, 125, 250, 500, 1000, 2000, 4000, 8000, 16000 Hz
Input Sensitivity/Impedance:  0,775V /56 k Ω
Rated Power/Impedance:  0,775 V/ 600 Ω
Hum and Noise (IHF A network):  100 dB
Residual Noise:  0,08 mV
Frequency Response:  10 to 100,000 Hz (+0 dB, -1 dB)
Harmonic Distortion:  0,005%
Dimensions (W x H x D):  482 x 143 x 328 mm

Weight:  6,3 kg net

Yamaha M-70


 Yamaha M-70
The Pure Zero Distortion Rule Sound
Here, at last is a power amplifier output stage that actually adds no distortion to the music signal. Although the actual techno;ogy involved in the ZDR (Zero Distortion Rule) amplifier is quite sophisticated, the basic principle of this incredibile high-accuracy amplifier is quite simple. Essentially the Zero Distortion Rule system consists of a distortion detector derives a signal corresponding to any distortion products originating in the amplifier itself, and the summer adds this signal back into the original audio / distortion signal - out of phase with the original signal. This effectively cancels the distortion signal, leaving the audio signal intact and virtually distortion-free. Of course, this system has no effect on distortion originating in the source signal, only on distortion generated within the power amplifier itself. From the above description we can see that if the derived out-of-phase distortion signal were somehow made larger than the original distortion signal, summing these signals would actually result in a negative distortion product. With this ingenious system, it has become possible to produce a power output stage that actually exhibits no inherent distortion.
 Zero Distortion Rule vs. Negative Feedback
Negative feedback (NFB) is the most commonly used means for reducing distortion in audio amplifiers. The amount of distortion reduction, however, is directly controlled by the amount of feedback applied. This means that in order to reduce distortion to zero, infinite feedback must be applied. Obviously, it is physically impossible to create infinite negative feedback, and therefore also impossible to achieve zero distortion by this method. Increasing application of negative feedback can only approach the zero distortion ideal, while ZDR actually permits crossing the zero distortion line and creating negative distortion, making it theoretically possible to completely eliminate distortion.

Zero Distortion Rule vs. Feed Forward
The feed forward system of distortion reduction attemps to cancel distortion by adding an inverted distortion signal to the audio signal at the amplifier's output where signal power levels are high. This means that expensive, hig-power feed forward circuitry is required, and overall power efficiency is extremely low. Also, the high-power feed forward amplifier required can actually add unwanted distortion.   Zero Distortion Rule performs its distortion cancellation at the amplifier's inputs, thereby eliminating the power problem. And since the ZDR circuit is essentially concerned only with low-lwvel signals, it cannot add any distortion of its own.
 Linear Transfer Bias and the "X" Amplifer
In addition to the ZDR system, the M-70 feature Linear Transfer Bias circuitry and Yamaha's remarkable "X" Power Amplifier system.   The Linear Transfer Bias circuit minimizes the problem of crossover distortion due to non-uniform linearity between the power transistors in a push-pull power stage. By applying precisely calibrated bias to each transistor in the M-70's cascoded push-pull power circuit and thereby staggering the operating point of each a perfectly linear composite transfer characteristic is achieved, ensuring negligible crossover distortion levels. 
The "X" Power Amplifier achieves extremely high amplification efficiency by switching the power supply voltage between two voltage levels - low and high - according to the size of the signal being processed. For average signal levels, for example, the lower supply voltage is used, while the high supply voltage is instantaneously switched in whenever a high-level music peak is detected. This system eliminates the power wasted in the form of heat that conventional systems must dissipate with large, finned "heat skins". The fact that the "X" Power Amplifier permits true high-power music amplification with maximum efficiency and minimum heat generation means that the entire amplifier circuit operates under optimum conditions at all times, ensuring the cleanest most accurate music reproduction. The unbeatable combination of the Linear Transfer Bias circuit, "X" Power Amplification, and Zero Distortion Rule amplifier design results in outstanding low-distortion power performance and incredible power efficiency for unmatched reproduction precision and exceptionally natural sound quality.

 "X" Power Purity
The concept of "pure power" is extremely important in achieving the highhest power amplifier performance. That is, the power source that supplies power to the actual power amplification circuitry must be capable of providing extremely stable power and at the same time supply as much power as the amplifier  circuitry demends without "running out".   The Yamaha "X" power supply easily meets the above requirements, with greater efficiency and power capacity than any other power system of its size or weight. In principle, the "X" power supply controls the amount of power fed from the AC line to the power supply to precisely match the amount of power supply to precisely match the amount of power consumed by the amplifier requires only a small amount of power for average music levels, or a large amount for high-level music peaks, the "X" power supply feeds precisely the required amount of power to the amplifier circuitry. Naturally, this means that all the supplied power is consumed, achieving remarkable power efficiency. In terms of stability, the "X" power supply affords exceptionally high regulation capabilities. Line supply voltage variations of as much as ±10% have no effect on the "X" power supply's output voltage, and resistance to influence by load variations is similarly high. The "X" power supply system permits the amplifier circuitry to operate at optimum efficiency under optimum conditions at all times, ensuring that the music source is reproduced with maximum accuracy.
 Speaker Level Controls
In addition to speaker A/B selectors that permit one-touch selection of two sets of stereo speakers, the M-70 features independent level controls for the left and right speakers in two stereo pairs. That is, you have independent left and right speaker level controls for speaker pair "A", and left and right level controls for speaker pair "B". These controls let you independently set the maximum power level that will be sent to the respective pair of speakers, protecting low-power-capacity speakers from excessive power levels, or matching the output level of two sets of speakers of different efficiency. Independent control over left and right speaker level lets you preset the balance of your system for optimum stereo imaging depending on the positioning of your speakers and the acoustics of your listening room.

20-LED Peak Power Output Meters
These bright, attractive power meters let you see at a glance just how much power is acctually being fed to your speakers. This makes it easier to determine the proper setting of the speaker level controls to prevent speaker breakup distortion or burnout due to power levels exceeding the speaker's capacity. zFor easier reading, these advanced meters feature dual switchable ranges and s peak hold function that displays the highset encountered power levels for considerably longer than the overall meter fall time.
Specifications
Minimum RMS Output per Channel: 
200 Watts (8 Ω, 20 to 20,000 Hz no more than 0,002% THD)
250 Watts (4 Ω, at 1 kHz, clipping Power)
Power bandwidth (8 Ω, Half rated power):  10 to 100,000 Hz (0,025 THD)
Input Sensitivity/Impedence (8 Ω, rated power):  1,41 V/25 k Ω
Frequency Response (8 Ω Half rated power, 100 kHz):  -0,5 dB
Signal-to-Noise Ratio (IHF A network):  124 dB
Total Harmonic Distortion (8 Ω Half rated power):
20 Hz : 0,0005%
1 kHz : 0,0005%
20 kHz : 0,001%
50 kHz : 0,003%
100 kHz : 0,006%
Intermodulation Distortion (8 Ω Half rated power 50 Hz : 7 kHz = 4;1): 0,002%
Channel Separation (8 Ω Half rated power , Input Shorted):
20 Hz : 100 dB
1 kHz ; 95 dB
20 kHz : 70 dB
Damping Factor (8 Ω 1 kHz):  Better than 200
Slew Rate (Sp Out):  200 V/µsec
Power Supply:  Matched to supply voltage and frequency of all area
Power Consumption:
USA and Canada : 600 W/1,200 VA
Europe and Australia : 900 W
Other Areas : 550 W
Dimensions (W x H x D):  435 x 133 x 380 mm (17-1/8" x 5-¼" x 15")

Weight:  13,7 kg (30 lbs 3 oz)