We would also suggest that prospective purchasers think about which aspects of the Stax headphones are causing them to pursue electrostatic listening in the first place. You might say “all of them” and that’s fair. But we do think there are likely to be two major camps seduced by the SR-009 and each will want different things from their amps. One camp will accept that headphones offer an alternative listening experience that is very revealing of the recordings at hand—albeit an experience that may never really sound precisely like live music (or like the presentation one might hear from fine, high-end loudspeakers). Members of this camp, we think, will value the SR-009 for its amazing clarity and ability to retrieve detail and will likewise prize the WES for its ability to maximize these attributes.
The other camp will also value the clarity and detail retrieval of the SR-009, but likely will be thinking that Stax has already over-achieved in both areas and will therefore look to balance out the detail retrieval of the SR-009 with an amp that—to some degree—supplies a subtle, almost analog-like kind of warmth. The WES, heard on its own, will seem very good to members of this second camp, but when compared to alternatives it may not be the preferred choice (largely because the Woo will faithfully reveal, but never even subliminally sweeten or warm up, the sound of the recording).
On Kate Rusby’s album 10 [Compass], the song "I Wish" offers treble that is clear without stridency (this is rare) and as the track plays through the WES the amp shows good dynamics without overshoot, while preserving (without overstatement) all of the delicacy the song has to offer. Similarly, the string bass is “there,” but is not overly or unnaturally prominent as reproduced by the Woo; instead, the WES gives the bass more of a foundational presence, just as the instrument might sound if heard live. Finally, the WES presents a good sense of the recorded space, and instrumental separation is excellent.
Later on this same album, the song “Maid of Llanwellyn” sounds a little midrange forward, with the slight sense of upper mid (2 - 3 kHz) rise and occasional resonance or clipping sound on Kate’s voice. This effect is not one we hear on most headphone/amp systems (or on live music if the PA is well done). This is an illustration of the subtly “stressed or shouty” quality we mentioned above, which—as we said—could be attributable to the SR-009, the Woo, or perhaps both. It doesn’t significantly undercut the many other things the Woo/Stax combo does right, but it is audible because it’s a small aberration that fall in a frequency band where the ear is quite sensitive.
On The Eagles’ Hell Freezes Over [K2 HD Music], "Love Will Keep Us Alive" has a delicacy and smoothness that sounds quite real and true to the sound of live music. Later on the same album, "Hotel California" has great guitar dynamics and separation, while deep bass seems excellent and very well defined. The bass in particular is impressive because the detail is sufficient that the drums clearly have the sound you get when you mic a drum, as was the case here, and then present the drum sounds through an amp with a touch of equalization added. The weight and depth of the bass are also very well rendered.
Turning to Shelby Lynne’s Just A Little Lovin' [Lost Highway] the song "Just A Little Lovin'" has good bass level and detail that is better than almost all other headphones on this track, at least those in our memory. Vocals sound a bit shaded and with a slight resonance, while cymbals are clear and clean and rim shots sound right. Turning to the track "Willie and Laura Mae Jones" we find superb instrumental separation on a moderately complex mix. This quality of clarity without stridency, and a good sense of pace, really makes this track a standout—as is the Woo amplifier, itself.
Let’s face it: the Stax SR-009 is the most expensive headphone on the market. The amps for the SR-009 are all in the same rather elevated price range, though some cost less than the Woo WES. If your questions about value examine the price of the whole system, this is a very costly setup. But, based on the “show me better for less” test, the Stax/Woo combination does quite well, and we think it can hold its head high.