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

Heathkit AR-1515

From its half-inch tall LED frequency readouts to its extraordinarily low distortion, the Heathkit AR-1515 is the finest receiver heath has ever designed.
The Ar-1515's digital Readout is far more accurate thas dial-type tuning. Simply tune to the exact frequency you want. Signal-strength and center-channel meters then help you "zero in" on the strongest signal and lowestFM distortion. There's even an oscilloscope output to monitor multipath distortion.
The amplifier section meets the same high standards. That extra margin of performance assures clean, wide-range sound without audible strain or struggle on even the most complex musical passages. And you'll hear the music over a background of silence - hum and noise are 65 dB below full output in phono and 80 dB below full output on high-level sources.

The amplifier section is also unmatched in convenience. All the frequently used controls - volume, input selector, stereo/mono switch, tuning - are on the front panel. The secondary controls are concealed behind a hinged door. Convenient indicator lights on the front panel show, the input you've selected. The digit light only when listening to AM or FM and only the necessary tuning meters are illuminated - signal-strength only for AM, signal-strength and center-tune for FM.
The bass and treble controls act primarlly at the frequency extremes to compensate for room acoustic and program deficiencies while maintaining smooth midrange response. And the AR-1515's  preamp out/amp injacks allow it to be used with any audio equalizer, such as the Heathkit AD-1305.

The AR-1515 is even easy to build. Obviously the AR-15151 is a complex and sophisticated receiver, but its well thought out, modular design and color-coded wiring harnesses simplify assembly

Amplifier Section
Frequency Response:  8 Hz to 45 kHz (+0 -1 dB);  4 Hz to 80 kHz (+0 -3 dB)
Intermodulation Distortion:  less than 0,08% (from 0,25 to 70 watts, full output)
Damping Factor:  greater than 60
Input Sensitivity:
Phono 1 , 2 :  2 mV
Aux, Tape , Dub. :  200 mV
Input Overload:
Phono :  greater than 100 mV
Aux, Tape,  Dub. :  greater than 10 V
Hum and Noise:
Phono (2 mV reference) :  --65 dB
Aux, Tape, Dub. (200 mV reference):  -80 dB
FM Monophonic
Frequency Response:  20  - 15,000 Hz  ±1 dB  
Antenna:  75 Ω or 300 Ω
Sensitivity:  1,8 µV
Selectivity:  100 dB
Image rejection:  90 dB
Mute Threshold:  0 -5 µV variable
FM Stereophonic
Channel Separation:  40 dB or greater at mid-frequencies;  35 dB at 100 Hz; 20 dB at 10 kHz; 20 dB (Nominal) at 15 kHz
Harmonic Distortion:  0,35% with 100% modulation
19 and 38 kHz Suppression:  60 dB
SCA Suppression:  60 dB
 AM Section
Sensitivity:  5 µV with 50 Ω direct input
Selectivity:  200 dB at 10 kHz
AM Antenna:  external static-shielded loop
Image Rejection:  70 dB at 600 kHz, 50 dB at 1400 kHz
Accessory AC Outlets:  One switched and one unswitched
Power Requirement:  120/240 V AC,  50/60 Hz
Dimensions (W x H x D):  21-1/2" x 6-3/16" x 15"
Weight (net):  35,8 lbs

Thorens TD 907

The Thorens  900 Series. The TD 907 - Ultimate Sub-chassis turntable, tradition reinterpreted.

Paying homage to the legendary TD 150 and TD 160 models of the sixties and seventies, THORENS® has reinterpreted the sub-chassis turntable with a state-of-the-art, ground-up development using the latest materials. Highest fidelity and dynamics were our main priorities during the development of the new turntable series. However, we also placed great importance on userfriendliness, a timeless aesthetics as well as flexible confi guration and upgrade options while retaining the traditional sub-chassis design.

Newly developed, ten-step adjustable pneumatic damping architecture
A conical polypropylene membrane under the platter bearing is decoupled from the triCom base via a visco/propylene layer. The air chamber thus formed under the membrane vents into ten apertures in the base plate which can be opened or closed with a slide.
Three-part platter
The polished aluminium platter features an acrylic insert that acts as a damping pad for the grooved area of the record. 

Tonearm board made of triCom
The tonearm board is also made of triCom and can be cut for almost any 9” and 10” tonearm at the factory.
Tonearm connection options  
Standard: mini 5-pin DIN soldered to RCA/XLR Option: soldered directly to RCA/XLR terminals

Mode of Operation:  Manual 
Drive System:  Precision-machined flat belt (inside)
Motor:  Newly developed, fully electronically controlled and stabilized AC synchronous motor. Plinth-mounted control board. Fine adjustment of speed.
Speeds:  33 1/3, 45 rpm
Speed Change:   Electronic
Platter:  1.5-kg aluminium sub-platter, 1.8-kg aluminium/acrylic outer platter
Damping:  Polypropylene conical membrane between platter bearing and chassis strut, pneumatic, adjustable
Base Plate:  triCom
Tonearm Board:  triCom 
Tonearm:  THORENS® TP 92/10“. Optional: SME M2, SME 309 or other 10” tonearms on request
Anti-skating;  Magnetic 
Power Supply:  External NT 900 electronic unit, 230/115V, 50/60 Hz
Connectors:  2 x RCA unbalanced, 2 x XLR balanced, 1 earth post, 1 mains terminal  
Dimensions (W x D x H):  470 x 380 x 190 mm
Weight:  10 kg
Finishes: White or anthracite structured enamel, Zebrano 

Rotel RX-202

Amplifier Section
Continuous Power Output: 
15 watts per channel, min. RMS all channels driven into  Ω form 50 to 20,000 Hz with no more than 1% Total Harmonic Distortion
17 watts per channel,, min. RMS, all channel driven into 8 Ω at 1 kHz with no more than 1% Total Harmonic Distortion
IM Distortion:  less than 0,5% at rated output
Frequency Response:  20 to 70,000 Hz ±3 dB at 1 watt
Damping Factor:  30 ( 8 Ω, 1 kHz)
Input Sensitivity/ Impedance:
Tape Monitor :  110 mV/40 k Ω
Tape, Aux :  110 mV/40 k Ω
Phono mag. :  2,2 mV/45 k Ω
Phono Cer. :  130 mV/100 k Ω
Phono Overoad:  80 mV (1 kHz)
Phono Equalization:  RIAA S.T.D. ±1,5 dB
Bass Control:  ±10 dB at 100 Hz
Treble Control:  ±10 dB at 10 kHz
Loudness Control:  ±10 dB/100 Hz;  =5 dB/10 kHz
Crosstalk:  50 dB/10 kHz
Hum and Noise:
Phono :  65 dB
Tape :  80 dB
Residual 0,5 mV
Speaker Impedance:  4 to 16 Ω
FM Tuner Ssection
Frequency Range:  88 to 108 MHz
Sensitivity (IHF):  2,9 microvolts
Signal-to-Noise Ratio:  65 dB
Harmonic Distortion:  0,2%
Selectivity:  40 dB ±400 kHz
Capture Ratio:  3 dB
Stereo Separation:  35 dB at 1 kHz
IF Rejection:  70 dB
Image rejection:  55 dB
Spurious Response rejection:  70 dB
SCA Suppression:  60 dB
AM Suppression:  54 dB
AM Tuner Section
Frequency Range:  525 to 1650 kHz
Sensitivity:  20 microvolts
Selectivity:  25 dB ±10 kHz
IF Rejection:  45 dB
Image Rejection:  50 dB
 General Section
Power Consumption:  115 W
Power Supply:  AC 120 V 60 Hz or AC 220 V, 240 V 50/60 Hz
Dimensions (W x H x D):  474 x 114 x 267 mm
Weight:  6 kg (13,2 lbs)

Luxman R-5030

AM/FM Tuner-Amplifier
A new (in 1981) budget tuner amplifier. Computer Analyzed Tuning (CAT) system establishes the optimum receiving condition automatically. Amplifier section employs the Duo-Beta Circuit for improved audio performance.

Flasher Tuning System Indicator
In case of FM reception, this indicator shows the direction of tuning. When a broadcasting station is coming near, the indicator begins flashing. Turn he tunning knob slowly to the direction shown by the indicator, and the flashing ceases at a point where the precise tuning point is obtained. At this time, the indicator shows the signal strength of the station  just tuned in. When 3 or more indicators light up, stble reception in stereo mode is feasible.

C.A.T. off Switch
Thanks to our innovative C.A.T. (Computer Analized Tuning) circuitry, this tuner-amplifier always provides an optimum reception according to the ambient conditions. Specifically, the anti-birdie and noise canceller circuits are sensing the electric field strength, interference by other stations, etc.

Audio Section
Power Output:  35 W (minimum continuous per channel both channels driven into 8 Ω with no more than 0,03% Total Harmonic Distortion)
Rated I.M.:  no more than 0,03% (8 Ω, 35 W/ch, 60 Hz :7khz = 4:1)
Frequency Response:  10 Hz - 70 kHz (±1 dB)
Input Sensitivity/Impedance: 
Phono ;  2,2 mV/50 k Ω
Monitor :  150 mV/35 k Ω
Phono Overal Voltage:  150 mV
Signal-to-Noise Ratio:
Phono :  77 dB (IHF-A weighted, 5 mV)
Monitor :  102 dB (IHF-A weighted)
Residual Noise:  0,5 mV
Tone Controls:
Bass :  +7 dB  -10 dB at 100 Hz
Treble :  +7 dB -10 dB at 10 kHz
Subsonic :  30 Hz (6 dB /oct)
High Cut :  7 kh (6 dB/oct)
Crosstalk:  70 dB ( monitor at 1 kHz)
Loudness Control:  +8 dB at 100 Hz ; +7,5 dB at 10 kHz (loudness control max. VR: -30 dB)
FM Tuner Sectio
Usable Sensitivity:  Mono 10,3 dBf (1,8 µV)
50 dB Quieting Sensitivity:  Mono 14,8 dBf (3,0 µV) (50 µ sec)
S/N Ratio at 65 dBf:  82 dB
Muting Threshold:  3 µV
Frequency Response:  30 Hz - 15 kHz ±1 dB
Distortion at 65 dBf;
100 Hz :  0,15%
1 kHz :  0,12%
6 kHz :  0,3%
100 Hz :  0,2%
1 kHz :  0,2%
6 kHz :  0,3%
Capture Ratio at 65 dBf:  1,5 dB
Image Response Ratio:  55 dB
IF Response Ratio:  90 dB
AM Suppression Ratio:  60 dB
Stereo Separation:  42 dB (100 Hz),  48 dB (1 kHz), 42 dB (10 kHz)
Spurious Response ratio:  80 dB
Alternate Channel Selectivity:  65 dB (±400 kHz)
SCA Rejection Ratio:  60 dB
AM Tuner Section
IHF Usable Sensitivity (1 MHz):  500 µV /m (loop antenna)
Image Response Ratio (at 1 MHz):  45 dB
Signal-to-Noise Ratio:  58 dB
Distortion:  0,5%
General Section
Power Supply: 110, 120, 220 - 240 V 50/60 Hz
Dimensions (W x H x D):  438 x 85 x 384 mm (17,5" x 3,4" x 15,4")
Weight (Net):  7,7 kg (17 lbs)

Trio KD-1033

Without doubt, one of the best value turntables on the market yesterday, supplied complete with cartridge, the KD-1033 offers exceptional performance at a realistic price.
Belt drive, synchronous motor using a specially developed polyuretane belt.
Wow and flutter less than 0,08%.
Resonsnce free tone-arm, statically counter balanced, stylus pressure adjustable from 0-3 grammes in 0,5 grammes graduations, pulley-weight bias compemsation.
Magnetic cartridge with diamond stylus, frequency response 20 Hz - 20 kHz
Plinth suspension system using three types of spring support with varying tension and pressure values.
Special anti-acoustic feedback feet with built-in rubber springs to absorb external vibration.
Removable acrylic dust cover.

Motor:  4-pole synchronous
Platter:  300 mm die-cast zinc
Speeds:  33-1/3 and 45 rpm
Wow and Flutter:  less than 0,06%
Rumble (DIN weighted):  -64 dB
Tone-arm length:  215 mm
Overhang:  9,5 mm
Tracking Angle Error:  ±1,5°
Tracking Weight Range:  0 - 3 g
Cartridge Weight Range:  4 - 10 g
Power requirements:  240 V AC
Power Consumption:  7 watts
Dimensions (W x H x D):  456 x 145 x 347 mm
Weight:  6 kg

Acoustic Research AR303a

AR 303a
More than fourty years of research and design have led to the production of this extraordinary musical component. The natural evolution of the classic 1967 AR 3aand the critically acclaimed 1994 AR 303, the new AR 303a is the pinnacle of the Acoustic Research loudspeaker line, combining reference quality sonic performance and furniture grade appearance.

The AR 303a Loudspeaker System is finished in a genuine rosewood veneer, accented by a unique gold logo and serial number plate. It features a redesigned creossover network, heavy duty 14 AWG internak wiring and bi-wire/bi-amp capability with improved gold plated 5-way binding posts.

True Acoustic Suspension technology
The AR 303a is based on Tre Acoustic Suspension design, a technology invebted by AR in 1954. a true Acoustic Suspension design uses the air inside of sealed enclosure to precisely control the excursion (back and forth movement) of the woofer cone.
The woofer cone is made of rigid felted paper, and when combined with a high compliance surround it moves like a piston. The long-throw voice coil is designed to undergo large disolscement while maintaining linearity. The compression annd expansion of air in the enclosure provides the linear restoring force to the cone. A True Acoustic Suspension design results in tight, controlled bass, excellent power handling capability and low distortion even at high output levels.

System Type:  3-way Acoustic Suspension
Special features: 
Filtered Soft Dome Technology ;
Vertical Symmetry Array
Frequency Response:  12 Hz - 20 kHz, ±3 dB
Driver Usage: 
For Low Frequency:  12" long-throw woofer
For Mid Frequency:  1-1/2" exposed dome midrange
For High Frequency:  3/4" exposed dome tweeter
Sensitivity:  85 dB (92,83V/M)
Impedance (nom/min): 6 Ω / 4 Ω
Power Rating: 
Minimum :  50 W/ch
Maximum :  250 W/ch
650 Hz ( 12 dB/oct low and high pass)
5500 Hz (6 dB/oct - low pass; 18 dB/oct - high pass)
Dimensions (W x H x D):  14,75 x 25 x 11,19 inch
Weight:  54 lbs
Finish:  Rosewood Vener

Arcam Two Plus

 Arcam Two - Audio Monitor Loudspeakers
The Arcam series of loudspeakers from A&R Cambridge are well engineered moving coil loudspeakers which provide excellent sound quality at affordable prices. They qre the result of several years of intensive research by A&R's designers into ways of achieving outstanding musical fidelity from compact sensibly priced speaker system
Design and Construction
All three loudspeakers are classic UK two way designs, using selected tweeters and A&R designed plastic coned bass drivers. These are otimally matched to rear ported (reflex) loaded cabinets, solidly constructed from high density 18 mm board with ultra rigid 19 mm "Medite" front baffles. The larger cabinets are heavily cross braced and damped,, to minimise cabinet resonances.
The Arcam Two+ are finished in quality real wood veneers (with black as a no-cost option) the compact.  All models have attractive removable black reticulated foam grilles of high acoustic transparency.

Each speaker uses an eight element close tolerance crossover network which has been designed handle high power levels without saturation or overheating. The crossovers make use of audiophile quality components wherever appropriate, including very generously sized,, low loss inductors,, plastic film capacitors and metal oxide resistors. The printed circuit (pcb) layout of each crossover network closely approximates to that of the classic "hard wired" design.

In the case of the Arcam Two+ models,, the pcb has also been designed to permit bi-wiring, with the treble and bass section brought out to separate pairs of terminals on the speakers back  panels.
Arcam Two+
System Design:  2-way reflex loudspeaker
Cabinet:  braced and optimally damped, constructed from 18 mm board with 19 mm Medite front baffle
Internal Volume:  14 liters
Drive Units:
One 180 mm cobex coned bass/midrange
One 20 mm soft dome tweeter
Crossover:  8 element, crossover frequency 3,0 kHz, 12 dB/octave
Connections:  Bi-wirable, 4 mm socket on back panel
Frequency Range:  42 Hz - 20 kHz
Impedance Modulus:  8 Ω nominal ( 6,5 Ω minimum)
Sensitivity:  88 dB/watt nominal, measured at 1 metre
Amplifier Compatibility:  15 - 70 W under normal operating conditions
Finish:  Walnut veneer or black  with black reticulated foam grille.
Dimensions (W x H x D):  223 x 378 x 280 mm (8,8 " x 14,9" x 11,0")
Weight:  8,2 kg (18") each

Arcam Three plus

Arcam Three - Ultra compact audio monitor loudspeakers

The Arcam series of loudspeakers from A&R Cambridge are well engineered moving coil loudspeakers which provide excellent sound quality at affordable prices. They qre the result of several years of intensive research by A&R's designers into ways of achieving outstanding musical fidelity from compact sensibly priced speaker system

All three loudspeakers are classic UK two way designs, using selected tweeters and A&R designed plastic coned bass drivers. These are otimally matched to rear ported (reflex) loaded cabinets, solidly constructed from high density 18 mm board with ultra rigid 19 mm "Medite" front baffles. The larger cabinets are heavily cross braced and damped,, to minimise cabinet resonances.
The Arcam Three+ is offered with a well finished walnut or black ash type vinyl wrap. All models have attractive removable black reticulated foam grilles of high acoustic transparency.

Arcam Three+
System Design:  2-way reflex loudspeaker
Cabinet:  solidly constructed from 18 mm board with 19 mm Medite front baffle
Internal Volume:  8 liters
Drive Units:
One 135 mm polypropylene coned bass/midrange
One 14 mm dome/cone tweeter
Crossover:  8 element, crossover frequency 3,5 kHz, 12 dB/octave
Frequency Range:  47 Hz - 20 kHz
Impedance Modulus:  8 Ω nominal ( 5 Ω minimum)
Sensitivity:  88 dB/watt nominal, measured at 1 metre
Amplifier Compatibility:  15 - 50 W under nrmal operating conditions
Connections:  4 mm socket on back panel
Finish:  Walnut or black ash vinyl with black reticulated foam grille.
Dimensions (W x H x D):  181 x 341 x 236 mm (7,1 " x 13,4" x 9,3")
Weight:  4,8 kg (10,6") each

Musical Fidelity A2 CD

 Musical Fidelity A2CD
Selectedmechanism and printed circuit boards
Sophisticated low jitter reclocking circuit
High quality Class A low impedance output stage
Remote control
Bitstream converter system
Standard 440 mm width
Random play function
Edit function
32track programming
Optical and coaxial digital outputs

Top level sonic performance and consistency
Greatly improved sound quality, imaging and tonality
High quality consistent sound with great presence and authority
Convenient operation from the listening position
Increased sound quality with smoother response and lower distortion
Matches the majority of alternative components
Plays back all tracks on the disc in arandom order
Allows easy taping of different tracks to best fit tape length
You can listen to the tracks you want in the order you prefer
Enables connection of external
Digital-to-Analogue converters or digital amplifiers
Frequency Response:  20 Hz - 20 kHz ±1dB
Signal-to-Noise Ratio:  better than -105 dB
Dynamic Range:  better than 95 dB (1 kHz)
Harmonic Distortion:  0,009% (1 kHz)
Wow and Flutter:  not measurable (Quartz accuracy)
Channel Separation:  better than 92 dB (1 kHz)
Output Analog:  2,0 V RMS
Output Digital:  0,5 Vp-p / 75 Ω  (coaxial)
D/A Converter:  8-times oversampling
Analog Filter:  4 pole CHV filter
Pick-up Type:  2D parallel objective lens drive, 3 beam laser pick-up
Laser Type:  GaAlAs semiconductor laser
Wavelength:  760-805 nm
Power Consumption:  10 watts
Dimensions (W x H x D):  440 x 95 x 340 mm
Weight:  5,1 kg
Standard Accessories:  Remote control handset

NAD 402 Tuner

The Model 402 embodies NAD's conviction that convenience, flexibility, and ease of use can be achieved with absolutely no compromise in sound quality. The 402 has AM and FM; preset distortion-free tuning for 60 radio stations

60 Presets 30 AM and 30  FM radio stations
NAD-Link Connectors allow control to and from other units
Blend facility to reduce noise at low signal strengths
75 Ω coax antenna connector
Lock facility to automatically tune precisely onto a station
Three separate modes of tuning with 25 kHz accuracy

Flexible Tuning
The 402 has three convenient tuning modes:
Search: Scans rapidly up or down in frequency, stopping automatically at the next strong station.
Preset: Up to 30 FM and 30 AM station frequencies can be stored in memory and instantly recalled. The "non-volatile" memory needs no battery or other power; frequencies are retained during power outages, even if you unplug the receiver for weeks at a time.
Tune: Dual-resolution tuning lets you scan rapidly through the broadcast band (with constant pressure on an up/down tuning button), or fine-tune in small 0,025 MHz steps by tapping on the buttons. This lets you optimise the reception of a weak station adjacent to a strong one.

Sensitive Digital Tuning
Precise digital frequency-synthesis circuits guarantee that each station is tuned with crystal-controlled accuracy. A dual-gate MOSFET FM circuit pulls in weak stations clearly but resists overloading on strong signals. A balanced quadrature detector provides consistently low distortion, even with over-modulated broadcasts. The composite stereo signal is phase-compensated to guarantee wide stereo separation at all frequencies, not just in the midrange.

Sharp selectivity, low noise
Linear-phase ceramic filters in the I.F. circuit provide an ideal combination of sharp selectivity and minimum distortion. Low-loss design gives the optimum signal level to the PLL MPX decoder, yielding a signal-to-noise ratio of nearly 75 dB with strong signals. So with local stations the ultimate stereo guieting is limited not by the receiver but the station itself.

FM Tuner Section
Input Sensitivity:
Mono (-30 dB T.H.D.+N) :  1,3 dBf (1,0 µV/75 Ω)
Mono (-50 dB SN) :  15 dBf (1,5 µV/75 Ω)
Stereo (50 dB SN) :  37 dBf (20 µV/75 Ω)
Stereo (60 dB SN) :  47 dBf (60 µV/75 Ω)
Capture Ratio:  less than 1,6 dB (45 to 65 dBf)
AM Rejection:  more than 60 dB (45 to 65 dBf)
Alternate Channel:  58 dB
Image Rejection:  70 dB
RF. Intermodulation:  60 dB
I.F. rejection:  90 dB
Subcarrier Suppression:  60 dB (19 and 38 kHz)
T.H.D. at 100% Modulation
Mono (1 kHz):  0,1%
Mono (100 Hz - 6 kHz) :  0,2%
Stereo (1 kHz) :  0,1%
Stereo (100 Hz -6 kHz) :  0,3%
Signal-to-Noise Ratio (at 65 dBf, IHF weighted)
Mono :  better than 80 dB
Stereo :  better than 74 dB
Frequency Response 30 Hz - 15 kHz:  ±0,5 dB
Stereo Separation:
1 kHz :  45 dB
30 Hz - 10 kHz :  35 dB
AM Tuner Section
Usable Sensitivity:  5 µV
Selectivity:  30 dB
Image Rejection:  45 dB
I.F. rejection:  35 dB
Signal-to-Noise Ratio (30% modulation, 50 mv Input):  45 dB
Total Harmonic Distortion:  0,5%
Physical Specifications
Power Ratting:   120,, 220 0r 240 V, 50/60 Hz
Power Consumption:  150 W
Dimensions (W x H x D):  420 x 91 x 273 mm
Weight [net/shipping}:  6 kg/7,1 kg

NAD 4020A Tuner

The NAD 4020A is a rationally designed and built, at moderate price,  AM/FM tuner, whose performance in most locations and with most broadcasts is audibly identical to that of many more expensive  and elaborate tuners. The 4020's quality of sound is limited only by the quality of the transmitted broadcast.
Recent dramatic advances in FM tuner circuitry, particularly in the development of inexpensive but high-performance "building block" circuit modules, have been incorporated in the 4020A to provide excellent sound at reasonable price.

Such crucial design parameters as sensitivity, low distortion and wide stereo separation have been given priority over the inclusion of costly superfluous features and esoteric circuitry whose benefits are totally inaudible except in rxtreme reception conditions. But no compromises whatsoever have been made in those performance areas which relate directly to the 4020's listening quality in normal and even somewhat difficult reception locations.
High Sensitivity
The "front end" tuning circuit, for example, employs a Junction FET amplifier, for an optimum combination of sensitivity to weak signals and resistance to cross - modulation from strong signals. The intermediate frequency (I.F.) amplifier, a high-gain IC, provides excellent limiting (static suppression), very good AM rejection (suppression of multipath interference), and smooth muting of interstation noise.
Low Distortion
While budget-price tuners commonly contain one or two ceramic I.F. filters, the NAD 4020A employs a total of three. Their sharp selectivity minimises interference from adjacent stations on the increasingly crowded FM dial, and their linear-phase respponse contributes to minimum distortion of stereo broadcasts. Multiplex stereo decoding is performed by the latest phase-locked loop (PLL) IC. In addition to low noise and wide stereo separation, the PLL decoder yields the lowest distortion in stereo reception - in particular, minimum inter-modulation between high audio frequencies and the 19 kHz stereo pilot tone.
Wide Stereo Separation
It is important to maintain wide stereo separation at low and high frequencies as well as the commonly specified 1 kHz midrange point. In the 4020A phase shift of the composite signal is minimised in order to preserve full low-frequency separation, and a special NAD phase-compensated crosstalk cancellation circuit increases high-frequency separation and minimises any residual distortion.
Instead of a costly and fragile moving-coil tuning meter the 4020A has a set of three LED indicator lights which form a remarkably simple and accurate meter. Either of two amber LEDs illuminates when the 4020A is mistuned to either side of a station frequency, and a green LED illuminates when the station is optimally tuned for minimum distortion 9within 0,025 MHz). The brightness of the green tuning LED indicates the signal strength, when it is dim the station is too weak for optimum reception.

For the music lover seeking uncompromised performance for a modest investment, the NAD 4020A is the logical choice. There are more costly tuners available, some of which have more impressive specifications,, but very few sound better in everyday use.
FM Tuner Section
Input Sensitivity
Mono -30db Total Harmonic Distortion+N :  10,9 dBf (1,9 µV/75 Ω)
Mono 50 dB S/N :  16 dBf (3,5 µV/75 Ω)
Stereo 50 dB S/N :  37 dBf (40 µV/75 Ω)
Capture ratio :  1,5 dB (45 - 65 dBf)
AM Rejection:  60 dB (45 - 65 dBf)
Selectivity:  65 dB
Image Rejection:  50 dB
IF Rejection:  75 dB
Harmonic Distortion:
Mono :  0,2%
Stereo :  0,3%
Signal-to-Noise Ratio:
Mono :  75 dB
Stereo :  70 dB
Frequency Response:  30 Hz - 15 kHz ±0,5 dB
Channel Separation:  42 dB (at 1 kHz)
AM Tuner Section
Usable Sensitivity:  250 µV
Selectivity:  30 dB
Image Rejection:  50 dB
IF Rejection:  40 dB
Power Rating:  220 V, 50 Hz   or 110 V, 60 Hz
Dimensions (W x H x D):  420 x 96 x 240 mm
Weight [Net/Shipping]:  4,2 kg / 5,6 kg

Boston Acoustic A70

In a stereo system, the loudspeakers are the key components. Because they are devices that you hear, the system can never be better than they are, if your speakers are less than excellent, accuracy will suffer, and so can your enjoyment.
The Boston Acoustic A70 is a highly accurate reproducer of music. In addition to faithfully recreating the full audible range of music, the A70 can image more accurately than most speakers offered at any price.

An accurate stereo image increases realism.
When you listen to a stereo system, close your eyes, and find out whether your mind's eye can "see" where each instrument is located.
Boston Acoustic speakers are well-known for their ability to recreate an accurate stereo image that increases realism and enjoyment. The slim profile of the A70 not only makes it easier for you to place the speaker unobtrusively in a room; more important from a music lover's point of view, the dimensions of the cabinet minimize unwanted sounds that would ordinarily muddy the stereo picture. The result is a crisp focused image.
Another characteristic that contributes to good imaging is a tweeter that's matched to the woofer in terms of its radiation pattern. A limitation of ordinary tweetere is that they radiate sound forward in a tight pattern, like a flash-light radiates light. In contrast, all woofers radiate over a broad area,like a table lamp. The tweeter incorporated in the A70 radiates in a very broad pattern, making the woofer and tweeter a well-matched team. Hence, the stereo image is clear and distinct.

The best combination of range and accuracy inn its price class.
The A70 maintaining the correct proportion while reaching farther into the bass than any other speaker in its price class. The quality of the drivers is largely responsible. The tweeter is the same one we use in most expensive nodel. The woofer is a helfty 8-inch driver designed to providethe best combinationof deep bass and efficiency. It reproduces the lowest notes in music - notes that most listeners never heat, except in live performances.

A room-size sound from as little as 15 watts
With very little  power, the sound of two A70 speakers will fill an average size room to overfloving. The A70 performs well with a receiver or amplifier as low as 15 watts per channel. Its efficiency means you can spend less money on your receiver or amplifier, and get excellent performance.

Frequency Response:  40 - 25,000 Hz ±3 dB
Impedance:  6 ohms nominal
Sensitivity:  1 watt produces 90 dB at 1 meter
Low-Frequency :  200 mm (8") long throw woofer with focused gap magnet assembly for low distortion
High-Frequency :  25 mm (1") soft dome tweeter with ferrofluid cooling
Crossover Frequency:   2000 Hz
Recommended Amplifier Power:  15 to 75 watts per channel
Power Rating:  75 watts nominal;  150 watts peak
Internal Volume:  28 liters
Cabinet Finish:  wood grain vinyl finish over non-resonant particle board
Dimensiond (W x H x D):  356 x  610 x 203 mm (14" x 24" x 8")
Weight:  11,8 kg (26 lbs)

Creek CD43

Creek compact disc player CD43 Features:
Infra-red remote control
High precision 24 bit, ΔΣ digital to analogue conversion
128 FS filter
3-beam optical laser pick up
16 program memory
LCD display - back lit green
Shuffle fnction ( random selection)
Repeat facility
Intro scan facility
Auto space facility

Frequency Response:  1 Hz - 20 kHz ±0,5 dB
Output Level :  2,2 V RMS at 1 kHz
Output Impedance :  600 Ω, min. Load 10 k Ω
Laser Type:  Semiconductor ALGaAs
Wavelenght:  790 nm ±25 nm
Light Output (cw):  0,18 mW typical
Signal-to-Noise Ratio:  better than 96 dB
Dynamic Range:  better than 100 dB
Number of Channels :  2
Total Harmonic Distortion:  less than 0,01% at 1 kHz
Power Requirements:  AC 220-240 V 50 Hz or AC 110-120 V 60 HZ
Power Fuse Rating:  T 250 mA or T 500 mA
Power Consumption:  15 Watts max

Dimensions (W x H x D):  420 x 70 x 289 mm