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





Avalon Ascendant loudspeakers

 

Superlative performance in a compact package, the Avalon Ascendant features many of the design philosophies pioneered in the Isis. Easy to drive and efficient, the Avalon Ascendant is a magican, throwing a huge and stable soundstage in even modest size listening rooms. The dynamic Avalon Ascendant combines startling bass response with concise transparency once deemed unthinkable for a transducer of this size. Transient bass impact is startling with vanishingly low 2nd and 3rd harmonic distortion properties. Combining exceptional efficency and easy of drivability, the Avalon Ascendant will extract truly dynamic performance from amplifiers possessing only moderate power output levels building vast and open soundstaging vistas.

Transparency and imaging clarity have been the defining hallmarks of all Avalon Acoustics transducers for 20 years with the powerfully concise Ascendant we have added yet another brilliant example of this heritage to our proud stable of products.

 

Crossover circuitry is hard-wired with surface-only conductors, eliminating deleterious sonic effects of printed-circuit boards and careful crossover control of all magnetic field interaction.

3-1/4" (inch) thick front panel supplies acoustically inert wave-launch platform. Constrained-mode damping system absorbs cabinet vibrations. Distinctive faceted cabinet design provides optimal polar characteristics and acoustically-engineered grille assembly decreases edge diffraction effects

 


Specifications

 Driver Complement:

Tweeter :  1” Proprietary Composite Neodymium Tweeter

Woofer :  Two 7" Nomex-Kevlar Composite Cone Woofers

Sensitivity:  89 dB

Nominal Impedance:  4 Ω

Frequency Response:  28 Hz - 25,000 Hz

Recommended Amplifier Power:  50 - 200 Watts

Wiring Methods:  Two Position Binding Post

Dimensions: (H x W x D):940 x 260 x 330 mm (37" x 10" x 13")

Weight:  34 kg (75 pounds) each

Sony PS-LX350H turntable

 

Belt-drive Stereo Turntable System with Speed control

 

Specifications

Motor and Platter

Drive System:  Belt-drive

Motor:  DC motor

Platter:  Aluminum die-cast, 330 mm diameter

Speeds:  33-⅓ and 45 rpm

Wow and Flutter:  less than 0,25% WRMS

Signal-to-Noise Ratio:  more than 50 dB (DIN-B)

Tone Arm

Type:  Static balanced S-shaped tone arm with  detachable headshell

Effective Arm Length:  220 mm

Overhang:  10 mm

Usable Cartridge Weight:  6 g to 10 g

General

Power Requirements:  120 V AC, 60 Hz (USA); 220 -230 V AC, 50/60 Hz (EU); 110 - 120 V / 220 - 240 V AC 50/60 Hz (other countries)

Power Consumption:  8 W

Dimensions (W x H x D):  450 x 145 x 350 mm (17-111/16" x 5-11/16" x 13-3/4")

Weight:  6,5 kg (14 lb 5 oz)

Adcom GTP-400 tuner/preamplifier


Adcom brings the superior performance of its separates into a price range previously associated with ordinary receivers with the introduction of the new GTP-400 Tuner/preamplifier. By combining the GTP-400 with one of Adcom's power amplifiers, you can now afford the clear sound, powerful dynamics and exceptional performance for which Adcom has been called "legendary" by the critics. The CTP-400 will put more power into your hands than you ever thought possible .. And its sound is truly revolutionary.

Because receivers have limited space, they cannot be equipped with the heavy duty, high-current, high-voltage power supplies available in the best separate components. And if a receiver was so equipped, it would generate unacceptable levels of heat and hum, inevitably degrading all performance parameters. Consequently, the overall performance of receivers is always compromised for the seeming advantage of all-in-one convenience and affordability.

 

The GTP-400 Tuner/preamplifier eliminates all such compromises.. By dividing the tuner/preamplifier from the power amplifier,, low-current, low-voltage elements are totally isolated from high-current, high-voltage elements ensuring sonic quality and superior performance. And because the GTP-400 is designed to be used with any of Adcom's power amplifiers, you have the advantage of choosing the right amount of power for your needs. If 60 watts per channel will drive your speakers to the level you want, consider our least expensive amplifier, the GFA-535. if you need more power, consider the 100 watt GFA-545 or Adcom's legendary 200 watt GFA-555. for the truly power hungry, the GTP-400 will drive two GFA-555's each bridged in mono, for an awesome 600 watts per channel.

 

Designers and engineers usually use Class A audio circuits in components where price is no object. Demanded by those who can distinguish outstanding sonic performance from merely average, Class A circuits are employed in the GTP-400's phono and high-level preamp stages. These circuits provide superior resolution and dramatic musicality. It took Adcom's approach to high performance/high value to make Class A affordable.

 

Several of Adcom's components have been favorably compared to other components costing two and three times more. The GTP-400 promises to keep faith with this tradition of exceptional value by delivering superb performance at a reasonable price.

 


The Preamplifier Section

Optimum Signal-to-Noise ratios at both the phono and high-level inputs ensure superior performance from your tresured Lp's as well as your new compact discs and a wide range of hifi video sources.

Proprietary linear-gain amplifiers in the high level and phono stages operate in full Class A to provide low distortion, low noise and high speed. High accuracy in the RIAA equalization circuit provides superb sound from high output moving coil or moving magnet phono cartridges. A separate recording selector allows listening to one source while recording another. Feedback tone controls and contouring circuits can fine tune your system to room acoustics or individual listening tastes.

 

The Tuner Section

Quartz referenced and digitally synthesized , the tuner has an accuracy 0f 0,00025% providing a significant reduction in audible distortion. Eight FM stations and eight AM stations can be programmed for instant retrieval at the touch of a button. Once a station is tuned in, it's locked in without drift. A touch of another button activates the scan mode, up or down. When reception conditions are marginal, a switchable high-blend circuit reduces background noise and fading of FM stereo signals.

 

The Sound of a Revolution

The price of the GTP-400 with a GFA-535 power amplifier is close to that of a good receiver. But that's as close as they get, beacause no receiver will deliver the wide dynamic range and lasting satisfaction of an Adcom music system. So if you would like to be part of the new movement towards bringing more power into your home, ask your Adcom dealer to demonstarate the GTP-400 with any Adcom power amplifier.

You'll hear what a revolution sound like.

 


Specifications

Preamplifier Section

Total Harmonic Distortion:  less than 0,01%

IM Distortion:  0,005%

Frequency Response:  20 Hz - 20 kHz ±0,1 dB

Max. Output Level:  better than 8 volts

Input Sensitivity for .5V Output:

Phono :  0,8 mV

High  Level :  78 mV

Signal-to-Noise ratio:

For .5V Output; Phono :  80 dB

For 2V Output; High level :  better than 95 dB

Output Impedance:  100 Ω

Tuner Section

IHF Sensitivity Mono :  11 dBf

Signal Strength for -50 dB Quieting

Mono :  13,5 dBf

Stereo :  37 dBf

Capture Ratio:  1,7 dB

Alternate Channel Selectivity:  75 dB

Separation at 1 kHz:  50 dB

Total Harmonic Distortion

Stereo at 1 kHz :  0,1%

Signal-to-Noise Ratio:

Mono :  80 dB

Stereo :  75 dB

Frequency Response:  30 Hz - 15 kHz ±0,5 dB

Antenna Impedance:  75 Ω or 300 Ω

Voltage:  117 V at 60 Hz ( 220 V at 50 Hz)

Dimensions (W x H x D):  432 x 80x 325 mm (17" x 3-1/4" x 12-3/4")

Weight:  6,8 kg (15 lbs) shipping

Technics SU-8055K amplifier


The main function of an amplifier is to amplify the input signal without adding to or subtracting anything from the waveforms of the original music. In other often-heard words, the ideal amplifier should be a straight piece of wire that provides gain without phase shifts, transient and other types of distortion over a wide frequency range. Technics sums all this up and calls it "waveform fidelity" and the SU-8055K is a good example of what we have done to make this kind of fidelity a reality. A glance at the specifications will show that what we say is not an idle boast. But we don't want you to just look. Listen to the SU-8055K and we're confident that you'll hear the qualities we're talking about.

 

DC Power Amplifier Helps Preserve Waveform Fidelity

Waveform fidelity has been greatly enhanced in Technics SU-8055K by the elimination of coupling capacitors not only in the signal path but also in the NFB loop. The lack of something is often a defect. But here, the absence of coupling capacitors means gain all the way down to 0 Hz and phase linearity in the bass frequencies. The result, in this DC power amplifier, is waveform fidelity - the accurate reproduction of musical waveforms.

Big Power and Matching High Fidelity

This amp offers plenty of power even if your special interest is thundering popular music with a lot of bass. It delivers 47 W at 8 Ω, from 20 Hz to 20 kHz with no more than 0,02% Total Harmonic Distortion. Reasons for this high fidelity are manu. A single-packed, low-noise dual transistor is used in the differential amplifier first stage for low noise and precise thermal tracking. Current mirror loading provides high open loop gain without increasing the level of noise. This stage gets help from the emitter-follower, in driving the Class A voltage amplification stage. The end result is minimal distortion in the high frequency range. In addition,, a 2-stage Darlington connection is used in the power stage, comprising a pure complementary circuit that provides high damping factor and low distrtion.


Super Quiet Phono Equalizer

The SU-8055K has an unbelievably high Signal-to-Noise ratio of 85 dB (at 2,5 mV sens. IHF A) when using an MM type cartridge, something rerely found in this amplifier's price class. There is a 3-stage, direct-coupling MM phono equalizer section, with direct coupling of the PNP-NPN transistors, plus a PNP transistor in the emitter follower. Low-output MC cartridges, which are growing in popularity, can also be used without adding an extra pre-preamp (another rarity in a moderate price amp). For the MC input, S/N ratio is 66 dB (at 170 µV sens. IHF A). A few of the reasons for low distortion and high gain are the separation of DC and AC in the negative feedback loop of the equalizer, 100% DC feedback, and the use of narrow tolerance components for negative feedback.

Treble and Bass Controls

An advaanced operatonal IC is used for negative-feedback-type tone controls. Bass and treble can be easily boosted or attenuated to suit individual tastes without  introducing distortion

Accurate Peak Power Indicators

These easy-to-read FL meters are used instead of conventional power output meters. They feature superior accuracy and near-instantaneous response time, and can be switched between two ranges: 0,1 W- 100 W when you are metering for full peak power: 0,01W - 10 W when metering in the more usual listening range. Brightness of the meters is switchable between bright and dim.

 

Versatile Recording Selector

The SU-8055K has two tape positions on the input selector as well as on the recording selector in a logical and practical layout. With this complete separation, you can do such things as dub from tape to tape while listening to your favorite disc. Or tape from your tuner while listening to music on another tape.

Rugged Stable Power Supply

The power supply is designed to handle the sudden current demands of high energy musical transient without losing sound clarity or introducing transient crosstalk. This is done by using two large-capacity 8,200 µF electrolytic capacitors in the bridged full-wave rectifier circuit and by employing a recently-developed transformer. It also supplies regulated voltage to the phono equalizer circcuit. The transformer coils are floated in a special resin to absorb unwanted vibrations. Even at soft volume levels you can enjoy your favorite music without being bothered by a noisy transformer.

Other Features

Muting circuit eliminates shock noise when the power is turned on and off, providing added speaker protection.

High filter to cut out high frequency noise such as record scratches and tape hiss. Subsonic filter reduces low-frequency noise.

Loudness switch for use when listening at low volume levels. Lows and highs are boosted to make up for "deficiencies" in the way the human ear responds at low volume levels.

Front-panel speaker selector lets you select either of two speaker systems (AorB) both or at once (A + B).

 


Specifications

Specifications

Amplifier Section (IHF)

Continuous Power both Channel Driven

From 20 Hz - 20 kHz

2 x 48 W  at 4 Ω

2 x 47 W at 8 Ω

From 40 Hz - 16 kHz

2 x 48 W at 4 Ω

2 x 47 W at 8 Ω

At 1 kHz

2 x 56 W at 4 Ω

2 x 50 W at 8 Ω

Total Harmonic Distortion:

Rated Power (20 Hz to 20 kHz)

0,03% at 4 Ω

0,02% at 8 Ω

Rated Power (40 Hz - 16 kHz)

0,03% at 4 Ω

0,02% at 8 Ω

Rated Power (1 kHz)

0,03% at 4 Ω

 0,02% at 8 Ω

Half Power (1 kHz) :   0,008% (8 Ω)

Half Power (20 Hz - 20 kHz) :  0,01% (8 Ω)

-26 dB Power (at 1 kHz) :  0,15% (4 Ω)

50 mW Power (at 1 kHz) :  0,2% (4 Ω)

Intermodulation Distortion:

Rated Power (250 Hz : 8 kHz = 4 : 1 ) :  0,03%

Rated Power (60 Hz  : 7 kHz = 4 : 1 SMPTE 8 Ω) :  0,02%

Power Bandwidth( both channel driven -3 dB): 

At 4 Ω :  5 Hz - 30 kHz

At 8 Ω :  5 Hz - 50 kHz

Residual Hum and Noise:  0,8 mV (0,8 mV, IHF  A)

Damping Factor:  18 (4 Ω);  36 (8 Ω)

Headphones Output Level/Impedance:  440 mV/330 Ω

Load Impedance

Main or Remote:  4 Ω - 16 Ω

Main and Remote:  8 Ω - 16 Ω

Input Sensitivity/Impedance

Phono MM :  2,5 mV/47 k Ω

Phono MC :  170 µV/100 Ω

Tuner, Aux :  150 mV/47 k Ω

Tape 1, Rec/Play :  180 mV/33 k Ω

Tape 2 :  150 mV/33 k Ω

Phono Max.input Voltage (1 kHz RMS): 

MM :  150 mV

MC :  6,5 MV

Signal-to-Noise Ratio

Rated Power (4 Ω)

Phono MM:  73 dB (85 dB IHF A)

Phono MC :  60 dB (66 dB, IHF A)

Tuner, Aux, Tape :  86 dB (97 dB, IHF A)

-26 dB Power (4 Ω)

Phono MM :  62 dB

Phono MC :  58 dB

Tuner, Aux, Tape :  63 dB

50 mW Power (4 Ω)

Phono MM :  58 dB

Phono MC :  56 dB

Tuner. Aux, tape :  60 dB

Frequency Response;

Phono :  30 Hz - 15 kHz (RIAA standard curve ±0,5 dB)

Tuner, Aux, Tape :  10 Hz - 60 kHz (-1 dB) ±0,5 dB (20 Hz - 20 kHz)

Tone Controls

Bass :  50 Hz +10 dB /-10 dB

Treble ;  20 kHz +10 dB / -10 dB

High Filter:  7 kHz, -6 dB/oct

Subsonic Filter:  30 Hz, -6 dB/oct

Loudness Control (Volume at -30 dB):  50 Hz , +9 dB

Output Voltage/Impedance

Rec Out :  150 mV

Rec /Play :  30 mV/82 k Ω

Channel Balance

Aux (250 Hz - 6300 Hz) ±1 dB

Channel Separation

Aux (1 kHz) 60 dB

General

Power Consumption: 500 W

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

Dimensions (W x H x D):  430 x 142 x 255 mm 916-15/16" x 5-19/32" x 10-1/32")

Weight:  7,7 kg (17,0 lb)