Stax CDP Quattro II CD player

Super High Resolution Compact Disc Player

 

Advanced DA conversion and 8-times oversampling/18-bit digital filtering bring to life the full potential of the 44,1 kHz, 16-bit CD format as never before. Its high fidelity and complete lack of coloration or "digital harshness" make this the CD player for analog diehards.

By no mean are all CD players that feature 18-bit processing and 8-times oversampling alike. The Stax technology and know-how that go into the Quattro II mean more polish and overall audio output closer than ever before to the ambience of a live performance.

Terminal facilities like a Direct Out with no analog filter and a buffer-equipped Variable Out represent the absolute state-of-the-art. In digital audio technology.

But more revealing than any discussion of the technical merits of this unit will be a listening test with your favorite CDs played on the Stax Quattro II CD player.

 

Specifications

Frequency Response:  20 - 20,000 Hz

Total Harmonic Distortion

DC - 8 kh :  0,0015%

8 kHz - 20 kHz / 0 dB  :  0,002%

At 1 kHz / -20 dB :  0,015% 

At 1 kHz / -60 dB  :  1,4 % 

Dynamic Range:  104 dB

Signal-to-Noise Ratio :  118 dB

Cross Talk :  -120 dB

Output Voltage:

Fixed Out :  2,2 V

Variable Out :  0 - 2,2 V

Power Supply:  117 V, 50/60 Hz

Dimensions (W x H x D):  440 x 144 x 402 mm

Weight:  10 kg

 

Stax UA-7cf

 Models UA-7 Features:

Type: Multi-use integrated arm with replaceable arm tube

Pickup cartridge acceptable: Magnetic or condenser types

Bearing:  Special dual suspension type (Ultra sensitive jewel bearing and stabilizer utilizing outer race of ball bearing)

Balancing:  Static balancing

Headshell;  U-shaped non-resonant structure compatible with all pickup cartridge design

Arm-lifter:  Oil dumped

Output Cable:  Noiseless low capacitance type of 120 cm long

Height adjustment: 45 - 78 mm between player board and cartridge  mounting surface of head shell.

Specifications:

Rotational Friction:  5 mg or less

Tracking Error:  0,10°/cm or less

Stylus Pressure Adjustment:  3 g/l revolution 0,1g step

Bias Compensation:  1 g - 3 g variable

Weight of Pickup Cartridge:  2 g - 16 g

Overhang:  13 mm

Distance Between Bearing and Turntable centers:  227 mm

Effective Length:  240 mm

Overall length:  340 mm

STAX SR-Λ (Lambda) Series

 The SR-Λ (Lambda) series have such pleasing sound quality because its diaphragm is oblong, instead of round, as in the SR-Σ Series. This shape approximates the elliptical shape of the outer ear so that you use your entire ear to listen to the sound, just as you would in a natural listening situation. In fact, the diaphragm is actually larger than the average ear's dimensions to take full advantage of the outer ear's response characteristics. The result is fuller low range response along with the uncolored mid and high range response typical of electrostatic reproduction.

The design approach of the SR-Λ Series won various prizes and especially the SR-Λ Signature is called "The best Headphone in the World".

 SR-Λ (Lambda) Normal + SRD-7sb

Stax introduced the SR-Lambda in 1979. still a worthy product in its own right, it has also served as the foundation for the most important earspeaker innovations since then. And in one respect it has not yet been bettered - the earpiece.  This designencloses the outer ear, housing an angled oblong diaphragm larger than the average ear's dimensions. The radiated sound is then captured by all parts of the outer ear and conducted to the eardrum - just like listening in any normal situation. The brain perceives a spacious sound field outside the listener's head. How unlike the typical headphone, whose earpiece crushes the outer ear, not permitting it to do its job, while the small dynamic speaker injects the music unnaturally into the ear canal.

SR-Λ (Lambda) Professional

Daimler Benz provided the impetus for the SR-Lambda Professional (1982) when they requested a unique earspeaker to analyze car noise. Stax achieved the desired low-frequency response by increasing the electrode gap and the polarizing voltage. These changes also created side benefits - the Lambda could now play louder than before, and with increased efficiency and less distortion. Until the advent of the Signature, the SR-Lambda Pro was the best earspeaker Stax  knew how to make; it remains a product second  to one only.

 The SRM-1 Mk2 Professional was designed to drive the SR-Lambda Pro or other earspeakers dirctly. Its pure class-A circuit eliminates audio transformers and coupling capacitors for detailed, natual reproduction. Like the SRM-T1, this unit can be connected to the tape loop of a preamplifier, or run directly from the line-level source - CD player, tape deck, tuner or mixing console - resulting in a remarkably simple and elegant signal path. It has output sockets for one Professional Series and one standard earspeaker.

 The SR-Lambda pro earspeaker can also be powered through the SRD-P portable energizing adaptor. It employs high-power IC's and Professional bias-voltage circuitry to extract the earspeaker's capabilities. The SRD-P operates not only on a household power source but also on batteries, allowing remote use for high-quality monitoring of location recordings. Its RCA input trminals enable direct connection to line-level outputs (as with the SRM-1 Mk2 Pro); but it also has a mini-jack input for use with portable cassette decks or mini CD players.

The SRD-7 Professional energizing adaptor connects to the speaker taps of a power amplifier, enabling one to enjoy Professional Series earspeakers  over whatever equipment one already owns. It contains advanced features like LC-OFC wiring and audio transformer windings, and an all-aluminum chassis to eliminate magnetic distortion. This adaptor is a particulary viable alternative to the direct-drive earspeaker amplifiers if one has made a major investment in state-of-the-art. Preamps and power amps.

SR-Λ (Lambda) Signature + SRM-T1

Surpassing the SR-Lambda Pro - probably the most widely acclaimed audio component of recent years - was a formidable task, but that is what the SR-Lambda Signature has accomplished; any superlatives not expended on the Lambda pro may now be safely employed. Two material changes are largely responsible. The Signature's transducing diaphragm is only one micron thick, a reduction of one-third from the Lambda Pro. And the signal cord is made of PC-OCC cable, specially cast from oxygen-free copper to preserve phase integrity through large linear-crystal-line structure.

A standard-setting earspeaker requires an amplifier which performs similalry - the SRM-T1.  this two-stage driver unit incorporates dual FET's and twin 6FQ7/6CG7 triode output tubes, thus combining transient speed with the smoothness and dimensionality sophisticated audiophiles have come to expect from vacuum-tube amplification. The SRM-T1 can accommodate both Pro Series and normal earspeakers.

The Signature System is urgently recommended for discerming audiophiles seeking the ultimate in musical information retrieval.

SRM-T1 Tube Driver 

Frequency Response:  DC-20kHz, +/-1dB

Gain:  60 dB

Harmonic Distortion:  0,02%

Input Impedance:  50 k Ω

Input Level:  100 mV

Maximum Output Voltage:  330 V RMS (1 kHz)

Bias Voltage:  230 V DC, 580 V DC

Power Requirements:  100 - 240 V 50/60 Hz

Dimensions (W x D  x H):  7-3/4" x 15-1/4" x 4"

Original Box (W x D x H): 18" x 9-1/2" x 5"  (+1 lbs)

Weight:  10,5 lbs

STAX SR-Λ (Lambda) Signature

 Above fifthy five years ago (1959), Stax became the first company in the world to develop and manufacture Electrostatic Headphone, "Earspeaker". Today, our experience is making a dramatic difference  that you can enjoy. For example, Daimler-Benz was so taken with "Stax technology" that they requested  a special earspeaker to test the acoustic environment in their limousines. This earspeaker became well-known as the SR-Λ Professional. Now, the SR-Λ Signature is the successor to the SR-Λ Professional. It is constructed of select materials and is hand assembled to meet the superlative standard of Mr. Naotake Hayashi, the president and founder of Stax.

Stax is proud to have created a new reference standard for earspeakers that obtains an even higher level of performance than the SR-Λ Professional. The Signature series SR-Λ uses a transducing diaphragm made of high-polymer that is only "one" micron thick. The signal cord is made of PC-OCC cable that is specialy cast from pure copper to preserve phase integrity through large linear crystalline structure.

 The SR-Λ Signature  is designed to operate at 580 V D.C. bias.it can be used with any Stax professional adaptor or direct drive amplifier. The SRD-7/Mk2 and the SRD-7sb/Mk2 are adaptors that enable the SR-Λ Signature and normal-bias earspeakers to work in conjunction with any high quality amplifier or receiver. The SRD-7/Professional is an adapter that enables two SR-Λ Signature  earspeaker (or two other pro-bias earspeakers) simultaneously to work in conjunction with a high quality amplifier or receiver. The SRD-X/Pro and the SRD-P are portable adaptors.  They allow the use of the SR-Λ Signature  in remote locations. The SRM-1/Mk2 Pro is a Class-A DC direct drive amplifier for any Stax earspeaker. The SRM-T1 is a Hybrid FET/vacum tube direct drive amplifier that is Specifically designed to highlight the SR-Λ Signature . It also will drive any Stax earspeakers.

 Specifications

Type:  Push-pull Electrostatic Oval Shape Units. Open back Enclosure

Frequency Response:  7 - 41,000 Hz

Electrostatic Capacity:  122 pF (including cord)

Impedance:  129 k Ω / 10 kHz

Sensitivity:  101 dB / 100 V RMS (input/ 1 kHz)

Maximum Output Sound level:  118 dB / 400 Hz

Bias Voltage:  580 V D.C. (standard)

Indication of Left/Right Channel:  Left [L]and Right [R] indicated at headband slides, and a solid line [L] & a broken line [R] on the cable

Ear Pads:   High quality soft vinyl leather

Cord:  6-core parallel low capacity wire/ full length 2,5 m [PC-OCC Continuous Crystal Copper]

Weight:  450 g (322 g without cord)

STAX SR-Λ (Lambda) Nova

 The Lambda Nova Series were designed for the person who loves the sound of the recent SR-Lambda Series but needs more modern sofisticated design. We put new shaped head-spring together with new sound units. As a result, the frequency responce was flattened and the wear confort was refined. The Lambda Nova Series carry the superiority of the former SR-Lambda Series and further more add special merit of new sound unit and head spring.

 The Lambda-Nova Series earspeaker is the fruit of the most up-to-date technology and many-years of experience of Stax that first developed and manufactured the electrostatic headphone, that is the first "earspeaker", in the world.

Differently from ordinary headphones, this earspeaker is equipped with neither magnet nor coil, but utilizes electrostatic force to generate sophisticated sound. In detail, the core of an earspeaker is composed of a thin diaphragm (oscillatory film) to which a DC voltage of 580 V is supplied. When audio signal is supplied to the electrodes, an electrostatic force is generated that drives the diaphragm to reproduce the sound. Thanks to this operation principle, the earspeaker reproduces sound very naturally and delicately in all nuances.

 Features

The Lambda-Nova Series earspeakers are advanced products of the SR-Λ series that has continuously been improved for more than 15-years.

For upgrading the electrostatic transducer, Stax improved not only the processing precision  of the thin diaphragm that has had an established reputation but also the structure of the electrodes to receive the audio signal. This, with the first rate technology cultivated through the manufacturing experience of the SR-Ω series.  As a result, Stax offers this earspeaker equipped with high quality transducers that are superior to others in sound clarity and excellent reproduction in detail at all levels.

 Most earspeakers made by Stax are designed to operate with the pro bias voltage (580 V/DC). The lambda-Nova series earspeakers also work with the pro bias voltage, however, Stax's old type earspeakers such as the model SR-1 that was put on the market in 1960 for the first time were designed to operate with the Normal bias voltage (230 V/DC). These two types of earspeakers can be discriminated from each other by the number of pins on the connector cord plug.  Namely, earspeakers whose connector plug has 6-pins are designed to use with the Normal bias voltage, while earspeakers whose connector plug has 5-pins are designed to use with the pro bias voltage.needless to say, the 5-pin connector of the Lambda-Nova series earspeakers should be plugged into a connector jack that has 5 pinholes and is usually identified with the indication of "Pro Only". If the lambda-Nova earspeakers is connected to a 6-pinhole jack for Normal bias, the result will be low volume and soft sound.

 

Specifications

Type:  Push-pull Electrostatic Oval Shaped Units, Open Back Enclosure

Frequency Response:  7 - 41,000 Hz

Electrostatic Capacity (including cable provided respectively):

Lambda-Nova Basic, lambda-Nova Classic : 120 pF

Lambda-Nova Signature :  110 pF

Impedance (10 kHz including cable provided respectively)

Lambda-Nova Basic, Lambda-Nova Classic :  133 k Ω

Lambda-Nova Signature :  145 k Ω

Sensitivity:  100 dB / 100 V RMS, Input 1 kHz

Maximum Output Sound Level:  118 dB / 400 Hz

Standard Bias Voltage:  580 V/DC

Left/Right Indication:  L & R indicators are provided on the Head Spring (Arc) and the left channel cable is marked with a solid line while the right channel cable is marked with a dotted line

Ear pads:  High quality synthetic leather

Cable:  6-core parallel low capacitance wire. 2,5 m (98-inch). Special low capacitance Cable; Lambda-Nova Signature

Cable Conductor:

Lambda-Nova Basic :  OFC

Lambda-Nova Classic, Lambda-Nova Signature :  PC-OCC (Pure Crystal  Ohno Continuous Casting)

Weight:

Lambda-Nova Basic, Lambda-Nova Classic :  440 g

Lambda-Nova Signature :  472 g

Body Only (without cable):  295 g

STAX SR-Σ (Sigma) Series

 Stax electrostatic earspeakers are widely used by the best recording studios and broadcast stations in the world. The simple reason for this is that these earspeakers deliver unsurpassed sound quality and the most accurate high fidelity reproduction possible. The general advantages of headphones over speaker systems are:

The acoustic conditions of the listening room do not affect the sound.

The diaphragms do not have to move much air (there is little load) therefore they can be made lighter to improve transient response.

There is no danger of acoustic feedback (howling) to the turntable.

The diaphragms are very close to the ears, so it is easy to pick up small musical details.

 The advantages of electrostatics over conventional headphones are:

The several micron thick high polymer film diaphragm is so light that it can respond accurately and instantaneously to the tiniest signal fluctuations.

There is no magnetic (hysteresis) distortion since no magnets or voice coils are used.

Electrostatic drive ensures uniform control over the entire diaphragm surface so there is no partial vibration or the cone breakup seen in dynamic type headphones.

 Stax (SR-Σ) Professional Series

The Stax professional series earspeakers have originally been developed for Daimler-Benz, the world-famous West German automotive manufacturer. They feature a wider electrode gap realized by a increased bias voltage (580 V). This resulted in a distortion-free bass sound along with a incredibly pure mid and high frequency range.

 The SR-Σ (Sigma) and Σ Professional are completely new kind of earspeakers developed over a long four year period. Their innovative design lets you enjoy more natural ambience reproduction than is possible with simple headphones. The diaphragms are placed forward away from in a normal music listening environment. The outer ear is not pressed, so the entire ear interacts naturally with the sound. Furthermore, a carefully designed cavity is employed to produce resonance characteristics simulating those occuring in a hall or room. All this results in a panoramic sound field without the feeling one has with conventional headphones that the sound is centered within one's own head. The employment of comfortable lightweight materials and a biomechanically engineered headband also contributes to the non-fatiguing pleasure of listening to music with the SR-Σ and SR-Σ Professional.

Stax SR-Σ (Sigma) System -

The Stax SR-Σ Panoramic Imaging Electrostatic Earspeaker design is a successful attempt to recreaqte a natural, realistic sound field from a headphone format. Headphones were originally designed for picking up Morse Code in communications, not recreating a musical sound stage. Until the introduction of the Stax SR-Σ, no headphone manufacturer paid much attention to ambience and its effect on musical imaging.

The SR-Σ earspeaker design locates an oval shaped electrostatic transducer in front of the ear at 90° angle to the ear. This does two things to improve the image perspective to the listener. First, by using an oval shaped transducer that is larger than the outer ear itself, the SR-Σ allows the outer ear to naturally channel the waveform into the inner ear. This allows the sound to reach the eardrum in the most conventional way. Second, the transducer is located in front of the ear, not over the ear. This removes the image perspective from within the listener's head and places the image in front of the listener. The SR-Σ transducing elements are positioned ideally in terms of the natural perimeters and auditory path of the ear. The result is optimum spacing for music in relation to the ear. The SR-Σ gives natural sound with none of the tight, sealed-in feeling, or the diminished scale sensaations conveyed by ordinary headphones.

Specifications SR-Σ [SR-Σ Professional]

Type:  Electrostatic / Push-pull High Bias

Frequency Response:  25 - 38,000 Hz [30 -35,000 Hz]

Sensitivity:  94 dB [98 dB]

Impedance (10 kHz):  122 k Ω [143 k Ω]

Maximum Output:  103 dB

Earpad:  Soft artificial leather, replaceable

Cord (low-capacitance):  2,5 m; 6-strand  6-pin plug [5-pin plug, PC-OCC]

Weight (without cord):  391 g [395 g]

STAX SR-Γ (Gamma) Series

 The SR-Γ (Gamma) and SR-Γ pro New are improved model of the original Model SR-5N. It offers the proven life-like sound qualities and performance of SR-5N Earspeaker and feature a new cage grid frame constraction. Thanks to the world's thinnest diaphragm, fashioned out of a high-moleculer film 2.0 (1.5 for Pro) micron thick, the SR-Γand SR-Γ Pro New achieve superb transient and uncomparable mid and high transparency.

  The new cage grid design gives full play to all the performance potential of the earspeakers and contributes to the light-weight, comfortable fit that will definitly enhance your listening pleasure. Stax SR-Γ professional has been improved incorporating newly designed ear pad. With this ear-pad, SR-Γ Pro's low frequency reproduction ability has been tremendously made rich.

 The standard SR-Γ earspeaker first appeared in 1985. its transducing diaphragm is two microns-thick, providing superior transient attack. It is supplied with the SRD-6sb energizing adaptor, which attaches to the output of a power amplifier. This adaptor is self-biasing (deriving its power from the audio signal itself); no AC power is required, thus granting the user greater flexibility regarding its placement.

  

Stax SR-Γ Professional specifically designed for the American market, the SR-Gamma earspeaker models occupy a price plateau below that of the Lambda products; since the Gammas utilize the same advanced technology and claim many of the same sonic attributes,, they constitute a genuine bargain. Their open-type oval enclosures prsent a clear, balanced sound field uncolored by cavity resonances or reflections.  The Gamma Professional contains the 1,5 micron-thick diaphragm and increased electrode gap and bias voltage found in the SR-lambda pro. It comes with the SRD-7 Professional energizing adaptor.

Specifications SR-Γ [SR-Γ Professional]

Type:  Electrostatic / Push-pull High Bias

Frequency Response:  15 - 30,000 Hz [15 -40,000 Hz]

Sensitivity:  103 dB

Impedance (10 kHz):  120 k Ω [140 k Ω]

Earpad:  Soft artificial leather, replaceable [large size]

Cord (low-capacitance):  OFC 2,5 m; 6-strand  6-pin plug [5-pin plug]

Weight (without cord):  190 g [192 g]

STAX History of Earspeakers

Stax Industries, Ltd, is japan's oldest and most honored manufacturer of specialized audio equipment. In 1959 Stax developed the world's first electrostatic headphone - marketed the following year as the SR-1.  [Today] Thirty years later, president Naotake Hayashi and his son Takeshi Hayashi continue their tradition by offering the finest headphones for both professional and audiophile applications. Stax prefers to call its headphones "Earspeakers"; such Ultra-High Fidelity devices for reproducing music can only be compared with the best cost-no-object loudspeakers, not other headphones. The term "Earspeaker" is therefore more descriptive of Stax's contribution to today's most advanced level of sonic transduction.

The Stax philosophy revolves around a single tent; the more precisely the reproduction mirrors the original live sound, the more clearly one may grasp the soul of the musical composition and performance. With this belief constantly in mind, Stax strives to make products providing the highest performance, reliability and value.

The most advancedd product of the Stax Industries, are:

Stax SR-Γ Series (Pro);

Stax SR-Σ Series (Pro);

Stax SR-Λ Series (Professional and Signature);

And SR-X, SR-5, SR-84 or SR-34

How Electrostatic Earspeaker Works

If we speak of a headphone, it usually means a dynamic one employing a dynamic transducer. In the dynamic transducer the driving force is applied only to the one part of the diaphragm which, therefore, must be stiff enough not to be deformed by air load. However, stiff materials considerably increase the diaphragm mass resulting in significant deterioration of transient response. In addition, the ununiform force applied over the diaphragm area leads to ehat is called "cone break-up". Hysteresis distortion caused through the magnet inevitable in the dynamic transducer cannot be ignored, either.

The electrostatic transducer adopted in the Stax earspeakers consist of two parallel-arranged fixed electrodes and several microns thick (2 microns in the SR-Sigma, the SR-lambda,the SR-X/Mk3 and the SR-5N. 6 microns in the SR-84 and the SR-34) high-polymer film diaphragm suspended in the middle of the electrodes. The low-mass film diaphragm is supplied with the biasing voltage from the energizing adaptors or from the SRM-1/Mk2. In the electret type earspeakers like  the SR-84 and the SR-34 the diaphragm is permanently charged minus. When the fluctuating voltage of the audio signal is applied to the electrodes, the diaphragm is pulled by the electrode which has the opposite charge of the diaphragm's and simultaneously pushed by the other electrode which then has the like charge of the diaphragm's. the continuous flow of alternating voltage in interpretation of audio signals causes the diaphragm to vibrate in faithful compliance with the amplifier output without time lag, assuring undistorted sound waves. This is why the Stax electrostatic earspeakers sound so good. The figure above shows the driving mechanism of the SR-84 and the SR-34.