Stax SR-009S Electrostatic Headphone

(3 customer reviews)

$ 4,325.00

The Best of the Best.

Stax invented the world’s first electrostatic headphone in 1960, achieving legendary status as the best performing headphones in the world. They have more in common with full range electrostatic speakers like Martin Logan than they do to conventional headphones. 

Think of them as “earspeakers” and prepare for the ultimate audiophile listening experience. The Model SR-009S is the current Stax “flagship”, the best of the best. 

  • Type: Push-Pull Open Back Circular Electrostatic Headphone
  • Frequency Response: 5 – 42,000Hz
  • Electrostatic Capacitance: 110pF (including cable)
  • Impedance: 145k Ω (including cable, at 10kHz)
  • Sound Pressure Sensitivity: 101dB / 100V r.m.s. 1 kHz
  • Maximum Sound Pressure:118dB / 400Hz
  • Bias Voltage: 580V DC
  • Ear Pads: Genuine Lamb Leather (direct skin contact), high-quality synthetic leather (surrounding portion)
  • Cable: Silver-coated 6N (99.9999%) OFC parallel 6-strand, low-capacity special wide cable, 2.5m full length
  • Weight: 1lb without cable / 1.3lb with cable
  • Electrostatic elements use no magnets, they are free from magnetic hysteresis distortion that is prominent in dynamic type headphones.
  • Made in Japan

All Stax models must be paired with a matching DC Bias Energizer / Amp to generate the electrostatic field and deliver the audio signal to the stators, choose from one of the following models. Click each model for full specs.

Note: Essence is the most up to date authorized Stax dealer in the USA.  Purchasing from Japan will void the warranty, buy with confidence, fast service, and free shipping in the USA from Essence, the electrostatic experts.

Select A Stax DC Bias Energizer / Amp


New Achievements in Diaphragm and Stator Design

The SR-009S further evolves the electrode established in the SR-009 as the integration of present technology.  New research reveals that if the fixed electrode becomes infinitely thinner, the air resistance will be decreased and the permeability of sound waves will be improved. 

The edges of electrode holes were smoothed through after-etching processing to reduce air resistance and the permeability of sound has been much more improved. Moreover, gold plating processing with large specific gravity further decreased the electrode vibration. Finally, the highest sound clarity has been achieved by reducing the resistance of electrode itself.

Tough solid aluminum chassis 
It secures the sound element firmly, contributing to improve the clarity and resolution of the sound. Furthermore, the case thickness has been reduced to the limit, making the flow of condensation-and-rarefaction air wave from the sound element smoother.

New designed guard mesh
Intensity has been increased by rounding the “guard mesh” of sound element, which lowered the influence of reflection and improved the resolution of the sound.

Audiophiles dream of owning full range electrostatic speakers but lets face it, they take up a lot of space and require robust amplification. Stax offers the equivalent or an even better listening experience for much less money.  Headphones take the room and its reflections out of the sound so all you hear is the recording, just the music.  Audio nirvana is here today with the Stax SR-009S earspeakers.

A unique custom Stax 5-pin cable was designed with the aim of achieving an even higher level of reproduction and performance. High-purity copper wire of 99.9999% (6Nines) adopted for the cable is silver-coated and finished with the most desirable form factor to drive the earspeaker.  High sound quality is achieved through the extreme thickness and separation of each conductor to minimize capacitance, cross-talk. and EMI.

Critical Acclaim:



Additional information

Weight 2 lbs
Dimensions 9 × 6 × 10 in


● Type: push-pull electrostatic large circular sound element, open-air type enclosure
● Frequency response: 5 – 42,000Hz
● Electrostatic capacitance:110pF (including cable)
● Impedance:145kΩ (including cable, at 10kHz)
● Sound pressure sensitivity: 101dB / input 100Vr.m.s. / 1kHz
● Bias voltage:DC580V
● Right/left channel indication: Golden solid line (left) and dotted line (right) on the cable
● Earpad: Genuine leather (skin touching portion), high-quality artificial leather (surrounding portion)
● Cable:Silver-coated 6N (99.9999%) OFC parallel 6-strand, low-capacity special wide cable, 2.5m full length
● Weight: 583g (including cable), 441g (without cable)

3 reviews for Stax SR-009S Electrostatic Headphone

  1. Andre’ Dufor, Audiophile Consumer Jan 2018

    The sound is beautiful and amazing. Are they worth it? If you can spend a good amount of time listening to music then they are worth it and more.

    Physical Quality: these are beautiful to hear. The build quality is wonderful. They are comfortable; i listen to them all-day whenever possible. These headphones are not meant to be mobile or in an area with dust, dirt, etc. These headphones are electrostatic; they don’t have traditional speakers in them. Instead, they have an incredibly sensitive diaphragm that is powered by 580V to produce an incredible sound. Treat them kindly and they will deliver an unreal sound.

    Source: Garbage in, garbage out. You MUST get Hi Res level of sound. Analogy….the stax are the equivalent of the best quality TV that money can buy (90″ 4K with incredible refresh rates, etc.)….are you going to put on VHS quality on that TV? If so, it will look terrible; all the terrible qualities will shine through in great detail. These SR-009s are no different. I highly suggest Tidal (make sure you buy the HiFi membership). These are incredible. I work from home and LOVE these. They are worth every penny and more. Andre Dufor, Audiophile Consumer Jan 2018

  2. Marius, Audiophile Consumer, June 2017

    I’m mostly familiar with Sennheiser HD 800 but the 009s takes the sound quality a few notches up. The first thing you will notice is the amazing transparency they posses. Unlike the HD 800’s treble peak the 009s is very well balanced, in fact is the most neutral headphones I’ve ever listen to. Everything is well integrated bass, treble, mid-range all that without sounding overly analytical. Sounds good with every thing you throw at it as long the music is well recorded. Even with MP3 320Kbps sounds so good, actually I’m hearing tiny detail that I wasn’t able to hear with my Sennheiser HD 800.

    The bass is one of the best I’ve heard very detailed ,vert tight and extends very low. Simply put on the world’s best headphones and you will be in “Dreamy Sonic Bliss”. All in all, a great Headphone that will bring a smile every time you listen to it Marius, Audiophile Consumer, June 2017

  3. Teman, Audiophile Consumer, Jan 2017

    The Best Stax Yet. Wonderfully detailed, transparent and musical. This headphone is so tonally accurate, nuanced and natural sounding that it makes all other end high cans that I’ve heard sound colored and distorted, especially when listening to classical music. If you’re a classical music lover and love the sound of acoustical instruments, this headphone will delight. It does require a top of the line amp and source. Stax amps are workable, made for these headphones. It’s not very forgiving of low res digital recordings. It tells it like it is. Teman, Consumer Jan 2017

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