Earspeaker System
SR-303 Classic
SR-303 + SRM-323II

Part of a history of ultra-precision sound checking

It’s not surprising that there are many music fans and audiophiles who have never heard of the audio maker STAX nor are they even aware of its existence. But even such people will have heard “the work of STAX”. This is because STAX products are used widely throughout the World by a large number of recording companies for sound-checking purposes in almost every stage of their production process. They are used to check that the sound has been recorded just as intended, for example by making sure that a Stradivarius really sounds like a Stradivarius, or to make sure that no unintended noise has found its way onto the mother disc or the stamper. This is because there are sounds that can only be detected by the human ear and that cannot be differentiated by a measuring device in terms of whether they are musical sound or just plain noise. STAX devices make use of high-polymer film which is several tens of times thinner than food wrapping. This is the diaphragm present in STAX electrostatic earspeakers. STAX is a Japanese brand that was the first in the world to pioneer electrostatic headphones of the condenser type, and STAX remains to this day, virtually the only company in the world active in this particular area. This is an earspeaker series whose high-range reproduction capacity has been proved especially by the appearance of SACD, DVD audio and other new-generation media. The combination that might be described as the global standard is the series leading up to the new product SRS-3050II. The new SRM-323II driver unit is compatible with media employing an increasingly wide band range. Because of the way in which the power section has been strengthened, it has outstanding playback capacity, recreating low-pitched sounds with real presence that really underpin the music rather than constituting a mere amorphous mass, while the flawless sounds that float above could even, if one so wished, be analyzed in terms of their very structure. Then there’s SR-303, a product in the earspeaker lineup that focuses especially on high sound quality. And we are now releasing SRS-3050II, a product that presents the ideal combination. 

SRS-3050II: The global standard 

The electrostatic type is structured to ensure balanced operation. This means that a balance circuit is present until the moment of conversion into air vibrations. This is the only system that makes it possible to enjoy the sound innate to the balance system. SRS-3050II is a system based on combination with the new SRM-323II driver unit, which has a significantly strengthened power transformer, and it has permitted a major expansion in dynamic range. The simple two-stage amplifying circuit configuration with FET characterized by high sound quality and low noise at the input stage offers sound quality fully worthy of being referred to as the global standard.


SR-303: The product of limitless experience 

This is the latest model in the SR-Lambda series, which houses an elliptical unit that fits the shape of the human ear and makes use of the same new high-polymer film diaphragm as the SR-404 Signature. Follow-up features in respect to input signals have been improved by brushing up the diaphragm and the cables. This is a model occupying a position at the center of the line-up that succeeds to the smooth and high-resolution tradition of STAX earspeakers. The rectangular unit that might be described as the precursor of universal design sends out sounds to the outer ear as a whole by means of parallel plane waves, and it has been designed in such a way as to emulate as far as possible the process whereby the ear perceives natural sounds and sounds in a concert hall. What’s more, the ear pads do not weigh down on the outer ear: an appropriate amount of space is ensured in the periphery so as to create a pleasant listening environment with no sense of pressure or unnaturalness. 

Specifications: SR-303 (Classic) Headphone
●Type Push-pull electrostatic earspeaker
●Frequency Range 7-41,000Hz
●Capacitance, including cable 120pF
●Sound Pressure Level 100dB/100V r.m.s.
●Cable / color 2.5 m, PC-OCC, low-capacitance cable / gray
●Earpad Highly permeable high-quality synthetic leather
●Weight including cable 450g
without cable 300g
●Channel Identification: Displayed on the headband arc section; Left: Solid line on cable; Right: Dotted line on cable.
●Operating temperature and humidity Between 0º and 35ºC, max. 90% (no condensation)
Specifications are subject to change without notice.

Specifications: SRM-323II Driver unit
●Frequency response: DC- 60 kHz (SR-303, when using one unit)
●Rated input level: 200 mV with 100V output
●Maximum input level 30 V r.m.s. with volume at minimum setting
●Amplification: 54 dB (x500)
●Total harmonic distortion max. 0.01% (1 kHz / during 100 V r.m.s. output) 
●Input impedance 50 kΩ (RCA) 
●Maximum output voltage: 400 V r.m.s. / 1 kHz 
●Standard bias voltage DC580 V (PRO bias)
●Power voltage AC120V-240V ± 10%, 50 to 60 Hz. (Adjusted for your area)
●Power consumption 29 W
●Temperature range for use Between 0º and 35ºC, max. 90% (no condensation)
●External dimensions 150 (W) × 100 (H) × 360 (D) mm (including knobs and terminals)
●Weight 2.9 Kg
Specifications and external appearance may be changed without notice in order to improve performance.

Copyright (C) 2007 STAX Ltd. All Rights Reserved.