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SR-009S

Driver
Electrostatic
Enclosure
Open-back
Weight
441 g
List
$4,545
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The round-cup Stax flagship that preceded the SR-X9000, with gold-plated MLER-2 electrodes etched a second time to reduce air resistance. Stax Japan has removed it from its product index, and Stax International still sells it.

Where to buy

List $4,545

Retailer prices checked 2026-10-21. We may earn a commission on purchases. How this works

Title block

Maker
Stax
Model
SR-009S
Made in
Japan
Released
2018
Transducer
Electrostatic
Enclosure
Open-back
Driver
Not published
Weight
441 g
Impedance
145 kilohms
Sensitivity
101 dB / 100 V r.m.s. at 1 kHz
Frequency response
5 Hz – 42 kHz
List price
$4,545 USD

Assembly drawing

1234567

Parts

  1. 1HeadbandArc assembly, 10-step click head pad, dual arc spring; material unstated
  2. 2GrilleCurved guard mesh
  3. 3Ear cupMachined aluminum housing
  4. 4Rear statorMLER-2 stator: multi-layer fixed electrodes, gold-plated, finish-etched openings
  5. 5DiaphragmUltra-thin super-engineering plastic film
  6. 6Front statorMLER-2 stator: multi-layer fixed electrodes, gold-plated, finish-etched openings
  7. 7EarpadsGenuine sheep/lamb leather (skin contact), synthetic leather (mounting portion)

Schematic electrostatic assembly, annotated with the Stax SR-009S’s published materials. Not to scale.

Engineering notes

  • MLER-2 fixed electrodes with a second etching pass on the openings to reduce air resistance
  • Gold plating on the fixed electrodes for density and conductivity
  • Housing and guard mesh reshaped from the SR-009; curved guard mesh
  • Cable of 6N OFC with silver-plated copper in a wide parallel 6-strand low-capacitance design

Design language

Round machined aluminium housings, a curved guard mesh and lambskin pads on the classic Stax arc.

Build the listening station

Desktop sanctuary

Electrostatic drivers run from a dedicated high-voltage energizer. Pair it with an energizer from the maker or an electrostatic specialist.

Related architecture

Sources