Philips - Direct Control

Better than belt. Better than direct.

What's better than belt and direct drive? The best of both in one turntable. The specs of direct drive with the acoustic and mechanical isolation of a belt drive. Until now, unheard of. But now you can hear it all on Philips exclusive new Direct Control turntables.

Philips' exclusive Direct Control electronic drive system

In all Philips Direct Control turntables a mini-computer at the driving disc constantly checks and re-checks the platter speed. Instantly correcting for any variations in line voltage, frequency, pressure on the platter, temperature - even belt slippage. That's how all Philips Direct Control turntables keep the speed constant and accurate.

Direct Control Free-Floating Subchassis.

Specially designed to give Philips Direct Control turntables superb acoustic and mechanical isolation. To cushion the platter, the tonearm - and protect your valuable records - from unexpected jolts, shocks and knocks. And to keep the rumble remarkably low.

Direct Control - Total Turntable Design

But Philips doesn't stop there. For us Direct Control is more than an exclusive new drive and suspension system - it's a completely new concept in total turntable design. Direct Control is specially designed straight, low mass, tubular aluminum tonearms, with very low friction bearings. To track even your most warped records accurately.

Direct Control Electronic Features.

Direct Control means reliable electronic touch switches for silent, vibration-free operation. Accurate electronic pitch controls. Digital and LED indicators to monitor platter speed and identify functions. And photo-electronic sensor to initiate the automatic tonearm return.

Direct Control Record protection

Philips even built in an accurate stylus pressure gauge, to keep the pressure off your valuable record collection. Nobody ever thought of that before. But philips thinks of everything.

Philips turntable models:

AF-977, AF-877, AF-867, AF-777, AF-677

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 (33⅓ 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

Aiwa AD-R470

 Nearly imperceptible quick reverse recording and playback is featured in AIWA's advanced AD-R470 cassette deck, which is certain to impress budget-minded audio enthusiasts everywhere. Amazingly quick 0,3 second auto reverse during both recording and playback is assured by AIWA's accurate radial-pivot mechanism, which turns the tape head 180 degrees in the blink of an eye.

Feather-touch full logic IC controls respond to a light touch, with Cue & Review for speedy location of desired pasages.

Sound quality features include Dolby HX Professional circuitry, which improves high frequency response regardless of the tape type, and an amorphous tape head for superb sound linearity. (The C, H, and U versions feature AIWA's super hard DX head for a corresponding level of performance.) Plus, Dolby B and C noise reduction reduce tape hiss for clear recordings that capture the dynamic  performance of today's digital and high-level analog sound sources. And, the fine bias control allows +/-20% adjustment to obtain the best response from Normal and CrO2 tapes.

 Dolby HX Professional

Not a form of noise reduction, Dolby HX professional is an advanced method for varying bias according to the characteristics of audio signals for an audible improvement in high frequency response. HX stands for "headroom extension'" and it operates during recording to dynamically adjust bias levels in response to the unput signals. This contributes to significant improvements in dynamic  range, while at the same time making possible "flatter" response in the upper frequencies. Under ordinary conditions, normal-position tapes recorded with Dolby HX professional actually outperform CrO2 tapes recorded without it in terms of high frequency response. You'll be amazed at the sound clarity and absence of distortion. Better yet, since Dolby HX professional is applied during recording only, the benefits can be heard when playing back these tapes on any playback equipment.

Plus Features:

Bi-directional auto rewind playback

Auto rec-mute

Auto tape selector: Metal/CrO₂/Normal

Rec/Play timer standby

Tape counter with reset

Headphone jack

Specifications

Track:  4-track, 2-channel

Tape Speed:  1⅞ lps (4,8 cm/sec)

Frequency Response

Normal Tape, at -20 VU:  20 - 16,000 Hz, 30 - 13,000 Hz (±3 dB)

CrO₂ Tape, at -20 VU:  20 - 17,000 Hz, 30 - 14,000 Hz (±3 dB)

Metal Tape, at -20 VU:  20 - 18,000 Hz, 30 - 15,000 Hz (±3 dB)

S/N Ratio:  65 dB (Dolby B, Metal); 78 dB (Dolby C, Metal, above 5 kHz)

Wow and Flutter (WRMS):  0,065%

Forward and Rewind Time for C-60 Tape:  90 sec.

Head:  REC/PB: Amorphous Alloy Head (H, U and C types; DX Head)

Erase Head:  Double-gap Ferrite Head

Motors:  DC servo motor x 1

Input Sensitivity Impedance  Line-In:  50 mV/50 kΩ

Output Level Impedance

Line Out:  0,36 V/50 kΩ

Headphone:  0,14 mW/8Ω

 Power Source:  AC  110-120/220-240 V, 50/60 Hz

Dimensions (W x H x D):  430 x 127,5 x 233,5 mm

Weight:  3,3 kg

ESS amt-1a

A loudspeakers translates electrical impulses into sound waves: Ideally,the loudspeakers/translator leaves nothing out and puts nothing extraneous in. It doesen't omit or color or mask. The perfect translator is perfectly simple. Simple and impossible until the Heil AirMotion Transformer revolutionized sound reproduction. The Heil midrange/high-frequency transformer is the perfect translator. There is only one compact system with a full-size Heil. The ESS amt-1a Bookshelf system. perfectly simple.

Your ears will appreciate the difference

Air-Motion Transformation: Midrange/High-Frequency

The Heil transformer, like most significant innovations, is much appreciated but a little mysterious. It is mandatory equipment for master reproduction techniques, yet the technological basis for its performance is often taken for granted. Actually, the Heil Principle of Air-Motion Transformation is as elegantly simple as it is effective.

The transformer's diaphragm resembles a lightweight pleated curtain mounted between powerful ceramic bar magnets. Conductive strips on the sides of each pleat cause the pleats to expand or contract in step with the signal. The air is squeezed out, and accelerated to five times the velocity of the diaphragm itself. In effect the Heil transformer uses air to move air, operating on the principle of pneumatic leverage.

Cone driving systems, on yhe other hand, are sluggish and inefficient by design. The cone's mass is huge, driving energy is largely devoted to overcoming its great inertia. The cone resonates and can "break up" at high frequencies. Acone driver only pushes air like a piston, in a one-to-one ratio.

The Heil driver's air-motion transformation ratio is five times better than that of any conventional speaker.

Other crucial design parameters are solved by the Heil Air-motion Transformer. The extremely light weight of its diaphragm eliminates resonance. Since the driving impulse is spread uniformly over the diaphragm surface, harmonic distortion from "cone breakup" is non-existent. These are inherent benefits of the Heilo design. For conventional speakers, they remain problematic goals.

REmarkable dispersion characteristics are another natural advantage of the amt's desugn. With a 120° pattern at 16 kHz, the amt maintains a solid expanse of stereo imagery to frequencies beyond audibility. Whatever the speaker/listener positioning, imaging is precise and penetrating.

The audible payoff is clarity, a perfect re-creation of the music 's fine and changing texture. Female vocal depth, the harmonic complexities of bow against string, and fleeting nuances of program ambience emerge with presence, immediacy, and power. It's all there.

Low Frequency performance

Deep, articulate low frequency response is provided by teh same 12" bass driver used in the top system of the ESS line, the amt-1a. Its 7 lb. 6,5 oz (3,36 kg) magnet assembly, rigid die-cast frame, and large-radius coil ensure state-of-the-art bass performance and dependability - response that feels substantial in the lower registers.

Power

The amt-1a Bookshelf system is designed to convert high power loads into clean; full sound, without effort and without distortion. The air-motion transformer's Teflon diaphragm both resists and dissipates heat outstandingly. The bass driver's 2" coil and high-temperature cone composition are significant factors in the system's low-end strength. "At power" the amt-1a Bookshelf is clear and dependable after other compact systems have reached their limits.

Dividing Network

The sophisticated crossover network designed for the amt-1a Bookshelf operates at 850 Hz, providing excellent woofer/amt phasing and precise signal distribution. Air-cored inductors are used to avoid the high-amplitude distortion possible with metal cored units. Altough air-cored inductors are an unseen refinement, they significantly enhance the linearity of a dividing network.

Controls

Your listening environment's acoustic character may prompt some fine adjustment of teh speaker system. A continuosly variable attenuation or accentuation control affects 850 Hz to beyond hearing, without blunting or peaking the higher frequencies and upper harmonics. The control panel is situated at the rear of the cabinet for easy access.

The construction of the amt-1a Bookshelf speaker enclosure reflects the same concern for distortion-free reproduction shown in the system's hardware. The interior dimensions of the enclosure are meticulously coordinated to the bass driver's specific characteristics. precise mathematical tuning determines port design.

Walnut veneer is matched, fitted to the cabinet superstructure, and hand-finished from sanding to final rubdown. A strong weave of sonically-transparent polyester fiber is used in the grille treatment, completing the speaker's appearance of simple, Functional grace.

The Final Arbiter

A classic integrity, from cabinetry to driver mounting detail, pervades the manufacture of the amt-1a Bookshelf. Its superiority can be demonstrated in many ways, reflected at lenght in technical data. But to the final arbiter, your ear, There is only proof. The audible proof. A critical evaluation of the amt-1a Bookshelf speaker system will reveal how perfect translation can be.

Specifications

Power Capacity: 75 watts continuous ; 350 watt peak Circuit breaker protected

Nominal Impedance: 4 ohms

Dispersion: 120 ° horizontal, 30° vertical

Crossover frequency: 850 Hz

Efficiency: 1 watt input produces 82 dB sound pressure at a distance of 15 feet (4 m)

Frequency Response: 50 - 20,000 Hz, ±3 dB

Heil Air-Motion Transformer

Total Radiating Area: 29 sq. in. (187,24 cm²)

Transformation Ratio: 5.0:1 velocity increase

Magnet Assembly Weight: 12 lbs. 15 oz. (5,87 kg)

Flux Density: 4,500 Gauss

Square Wave Rise Time: 15 microseconds at 5,000 Hz

Low Frequency Driver

Nominal Diameter: 12" (30,48 cm)

Voice Coil: 2" (5,08 cm)

Magnetic Assembly Weight: 7 lbs. 6,5 oz. (3,36 kg)

Flux Density: 10,500 Gauss

Controls

Midrange/High Frequency: Continuously variable attenuation oraccentuation from 1 kHz to beyond audibility

Decor

Finish: Oiled walnut veneer

Grille Color: Brown

Dimensions: 24" x 14" x 14" (60,96 x 35,56 x 35,56 cm)

Shopping Weight: 60 lbs (27,27 kg)

Heil Air-Motion Transformer by ESS

Figure 1

The heart of the Heil air-motion transformer is a featherweight pleated Teflon diaphragm bonded with conductive aluminum strips. The diaphragm is suspended within a massive magnet structure. Its steel conductor plates concentrate an intense magnetic field around the diaphragm.

When a signal passes through the diaphragm's foil strips, the bellows-like motion of the pleats squeezes air out at five fimes the speed of the vibrating diaphragm itself. This virtual "instant acceleration" distinguishes the Heil from all other loudspeakers.

Figure 2

Polar response curves at a wide range of frequencies reveal a broad horizontal dispersion pattern through-out the audible spectrum. The ability of the Heil air-motion transformer to disperse even the highest frequencies over a large area assures full stereo imaging anywhere in the listening environment.

Figure 3

The superior response of the Heil air-motion transformer is revealed in its relatively flat impedance. The entire system's frequency response curve shows a typically broad, linear bandwidth. This exceptional efficiency at all frequencies permits the amplifier to deliver necessary power at ultrasonic frequencies.

Figure 4

A pair of drawings illustrates the movements of the Heil's pleats and the corresponding musical sine wave signals. In Figure 4A, the front facing pleats contract as the sine wave rises, forcing the air out under pressure. Meanwhile, the pleats opening towards the rear draw air in. When the sine wave reverses, as shown in Figure 4B, the pleats contract in the opposite direction.

Figure 5

The "squeezing" action of the heil diaphragm's pleats viewed in detail from above. As the pleat walls (A) squeeze together, they force a large amount of air to accelerate under pressure through a narrow opening (B). The folds are 5.3 times as deep as they are wide, resulting in a 430 percent increase in air velocity.

AVID Parte II "La soluzione"

Avid risolve finalmente i problemi della diffrazione acustica.

Pur costantemente impegnati al raggiunimento della più alta fedeltà, molti altoparlanti anche trai piùcostosi, sono generalmente affetti da un difetto comune; suonano come altoparlanti, o - più esattamente - si sente sempre e comunque che il suono proviene da un box (cassa, scatola etc.)

Il Vostro cervelldo "sente" la scatola

Anche chi è completamente privo di nozioni di psico-acustica, sa che gli altoparlanti hanno ormai talmente condizionato il nostro cervello che questo all'ascolto subito "riconosce" i suoni come provenienti da una scatola, con ben determinate caratteristiche di forma, misura etc.

Cosa contribuisce a creare questo spiacevole ed innaturale effetto di limitatezza?

Principalmente le onde sonore riflesse o ri-radiate quele cioè che rimbalzano sugli spigoli della cassa e del panello frontale , è a causa loro che nostro cervello "inscatola" la musica.

Niente diffrazione, niente scatola

Il problema è illustrato graficamente qui sopra. Eliminando gli spigoli del mobile e del panello frontale si riduccono gli effetti di diffrazione vale a dire si elimina l'effetto scatola. E questo è ciò che abbiamo fatto con gli altoparlanti della nuova serie Avid i Minimum Diffraction Loudspeakers™

Per aprire la scatola, abbiamo chiuso il coperchio.

trovare la soluzione è stato incredibilmente semplice. Abbiamo ideato un insieme di componenti, cassa e pannello frontale che vengono a formare un sistema acustico totalmente integrato, che elimina le diffrazioni causate dal mobile e quindi l'effetto scatola a tutte le ... scatole parlanti. I nostri nuovi tweeter e midrange vengono installati con speciali flange che ne aumentano la dispersione e che riducono al minimo la difrazzione (le abiamo chiamate Optimum Dispersion Couplers™). I pannelli frontali sono stati raelizzati in modo da completare ed enfatizzare la dispersione uniforme delle onde sonore senza alcuna diffrazione. Anzi per renderle ancor più libere da ostacoli e ridurre perciò quel dannoato "effetto scatola". Queste semplici, ma significative innovazioni, unite alle oramai famose linearità ed accuratezze dei prodotti Avid Vi permetterano di scoprire una dimensione totalmente nuova d'ascolto dandoVi un senso di spazialità e realtà prima d'ora mai raggiunti.

dbx Encoded Discs

Recordings of exceptional clarity and dynamic range

for your increased listening pleasure.

The technology behind dbx encoded discs.

DIAGRAM DEPICTING THE COMBINATION OF SIGNAL COMPRESSION

DURING ENCODING AND EXPANSION DURING DECODING THAT RESULTS

IN SURFACE NOISE REDUCTION AND DYNAMIC RANGE RETENTION

ON dbx ENCODED DISCS.

'' dbx '' is a trademark of dbx Inc.