Stax SR-09 Electrostatic Headphones

Beautiful Pair of The Highly Regarded Stax SR-09 Electrostatic Headphones.
Like New Condition with original box and packing.
AMAZING HEADPHONES !

I’m giving the Stax SR-009 five stars not because it’s perfect but because it’s probably the best there is, and any further improvements may be some time coming.

For reference, I also own some of the SR-009's chief competitors – Sennheiser HD-800, Audeze LCD-3 and Stax’s own SR-007A – so I hope my comments can be seen as objective. I must admit a bias toward electrostatics for their speed and transparency (I also have Stax SRX/III's and 507's), and believe the most valid comparison would be with the SR-007A because it's physically similar to the SR-009 and, on a pro-vs-con basis for sound quality, is roughly on a par with the Sennheiser and Audeze models.

The most obvious difference between the SR-009 and the SR-007A is in the mid-range, where the SR-007A’s subdued response gives them their dark and laid-back sound, which of course some will prefer. The SR-009 is more forward and neutral in this region, which also benefits the bass through greater harmonic texture. Voices are uncannily real and instruments beautifully separated. What slightly troubles me however is that the relative rise in the mid-high frequency response of the SR-009 tends to emphasise the sibilance that is also present in the SR-007A, but never really intrusive. With the SR-009, sibilance and percussive transients (including clicks and ticks) can be quite prominent. While this can add to the “wow” factor, it can also accelerate listening fatigue.

All in all, however, the SR-009 is superb. And by the way, I’m not one of those who say you need to double your investment in amplification to get good sound from these. While you do need a special driver, it can be quite simple and affordable. The SR-009 is more efficient (easier to drive) than the SR-007A.

 

ENCLOSURE:
Aluminum is a metal good for sound and suitable material for audio equipment. It is abundantly used, e.g. at the frame supporting the appearance and sound element, to realize high-quality sound, rigidity and lightweight. Almost every part of the SR-009 is manufactured through precise machine processing.  

CABLE:
The high-purity copper developed from the necessity of wiring large-scale integration circuits is also known as high-quality audio cables. High-purity copper wire of 99.9999% (6Nines) purity adopted for the cable is further silver-coated and finished with the most suitable structure to drive the earspeaker.

EARPAD:
The earpad of a new design is carefully made by a craftsman's hand and features both the real leather with good humidity environment and the cushion material with moderate elasticity.

The new earpad enables hours of comfortable listening to music.

ARC (head band):
The arc is equipped with a position adjustment mechanism of 10-step slider and corresponds to the wide range of cranial form with individual difference.

SR-009 SPECIFICATIONS:

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

Left & Right Identification: "L" and "R" indicated on the arc assembly (inside head spring) Left channel cable is marked with a solid Line. Right channel is marked with a dotted Line.