The Woo Audio WEE Electrostatic Headphone Energizer
Electrostatic speakers have been around for ages. Perhaps you're familiar with the big flat-panel speaker systems from Quad, MartinLogan, Sanders, SoundLab, Audiostatic, Silberstatic, etc. They have potential to sound phenomenal but can be all kinds of picky regarding placement and amplification. Electrostatic headphones have also been around for a long time and have earned a reputation for being exceptionally clear sounding. But there's also a catch - several of them actually.
First is the price: we might say that worthwhile "entry-level" dynamic headphones start around $99, and go as high as $1500 or so at the high-end. Contrast that with Stax where the entry level earspeaker is $420, a midrange unit is $1100, and the top model is $5250. The Stax brand driver units start at $500 and rise as high as $2400, though most serious Stax aficionados use 3rd party models that go even higher in price. So the overall cost of entry tends to be significantly higher than dynamic or planar based systems.
Next comes the confusion of differentiating the models. Experienced Stax users may scoff at this complaint, but it really is confusing for newbies to make sense of the terms "Lambda", "Signature", "Omega", etc which don't really line up with the advertised names of any production model on the market today. Part of this is caused by the fact that Stax has been making earspeakers since 1960 and many of the older models are still in use. This is somewhat rare among headphones, especially compared to the world of speakers. Yes, you still see some Sennheiser HD580s that are nearly 20 years old, and the venerable Sony MDR-V6 is even older. Heck, the Beyerdynamic DT48 is ancient. But generally speaking the Stax models seem to have a unique ability to generate a cult following, and people tend to hang on to them for a very long time. Because of this it is easy to search eBay and become quickly confused by the variety and scope of what is still available. I suggest checking out the current lineup at the Stax USA website to see which models are currently in production. I also recommend the Stax section at Wikiphonia to get some good background information about when each model was made. Stax is certainly not the only manufacturer of electrostatic headphones but most others are out of production. And to be honest for the general headphone population Stax is synonymous with electrostatic headphones, period.
These two issues conspire to keep newbies somewhat intimidated and therefore ignorant of the electrostatic phenomena. This is too bad because people who make the switch to 'stats often remain, never going back to regular dynamic headphones. So clearly it is worth getting past these barriers if at all possible.
A quick primer on 'stats: they work differently from dynamic or planar magnetic designs. Because of the way they work, they have far higher voltage requirements and thus demand special amplification. In addition to the Stax brand driver units there are options from Woo Audio, HeadAmp, Ray Samuels Audio, and Cavalli Audio, with at least 1 other model (Eddie Current Electra) in the works and some DIY designs (like the eXStatA and Kevin Gilmore's KGSS) floating about.
More choices usually equate to more competition which results in lower prices, but the 3rd party electrostatic amps don't really work that way. Most of them are intended to be flagship state of the art products and have correspondingly hefty prices. The one commercially available exception is the Woo Audio GES which starts at $1450 in basic form and can exceed $2500 with upgrade options. And that's before we figure in tube upgrades. So while it may be cheap as far as these things go, it still isn't what I'd call a budget product.
Stax did at one time provide some low priced options for driving their earspeakers: the SRD series was made from 1960 through 1986. Stax called these units "energizers" rather than driver units because they paired with a speaker amplifier and acted as a step-up transformer to provide the required high voltage. These are available on the used market for affordable prices. The downside is obvious though - the newest of them is 25+ years old, and newbies should absolutely not be poking around inside to make sure everything is in order.
Enter the WEE
Woo Audio took the idea of the affordable transformer box and ran with it. The result is dubbed the WEE for Woo Electrostatic Energizer ($499). It works in the same way as the older Stax units - simply attach a speaker amp (anything with 3 watts per channel or more will do), plug in some earspeakers, and enjoy. The unit has a switch on front for selecting pass-through mode which allows the signal to pass through unmolested to your speakers. This allows the WEE to be easily inserted into nearly any system. The only caveat is that the input grounds are tied together, so bridged/balanced amplifiers should not be used (Pass Labs for example).
The unit itself is very well built and uses an enclosure similar to several of the other Woo Audio amps. Woo is known for their eye-catching designs, and the WEE does look a little plain compared to something like the Woo WA22 with its protruding tubes and transformers, but it's still very well done overall. The size - 12"w x 8.5"d x 3.75"h - allows it to fit easily in most situations. The weight - a healthy 13lbs - is indicative of the substantial build quality.