Not headphones, but “earspeakers” as Stax calls its unique designs. And for once, it’s a sensible name, not merely PR phrasing. The Stax designs really are like having loudspeakers hanging next to your ears; the SR-207 earspeaker design we reviewed here does have pads that contact your ears and a headband to keep things in place, but honestly, we know of no headphones you’re more likely to entirely forget you’re wearing.

We remember once, many years ago, undertaking a comparative test of some 70 different blank cassette tapes, a nightmare scenario which was made not only possible but distinctly less horrific by the loan of Stax’s then range-topper, the SR-Lambda Signature, which used a dedicated valve amplifier to feed them. It was a unique listening experience, like having a mobile Quad electrostatic panels on each side of your head. We were rapt, and don’t recall any similar experience since, though memory is, of course, a pernicious master. 

Stax was then Japanese; the company failed in the 1990s, but was revived, and the brand is now owned by Edifier, the Chinese company best known for its dozens of designs of computer speakers and docks, some of which we’ve reviewed and found pretty enjoyable. The Stax brand is still, however, made in Japan.

Stax’s current top-of-the-range electrostatic earspeaker, the SR-009, has actually reverted to a circular earshell, so we were delighted to receive a design further down the range which is still based on those spectacular Lambda earspeakers of old. They still have their own amplifier, though with this package it is solid-state, the combination of SR-207 earspeakers and SRM-323S driver unit being labelled the “SRS-2170 earspeaker system”. You could buy the earspeakers ($699) or amplifier ($799) alone, but since they connect via a five-pin PRO bias output socket, you might find little else to use them with. 

The SR-207s are as close to fully open as headphones get, using an oval push-pull electrostatic panel inside their large unadjustable rectangular headshells, with almost as much sound flooding out into the room as heading in the earward direction. Not that you’d be using them on the bus, anyway, given the requirement of mains power for the amplifier. But it is worth remembering that they also allow sound from the room to enter freely; we started listening to these while the missus was in the room watching television, and it was clearly not going to work for either of us. These are headphones for lone listening.

We reckon you’ll be doing a lot of it. The presentation of the SR-207s is uniquely airy, open, detailed and stunning in its portrayal of the soundstage, which was as close to in front of us as we’ve ever had headphones deliver; when not in front, it was soundstaging within the head, and not positioned around and above, as is the norm. Electronic bass and synth lines may not fill your head with fatness, but you’ll never hear things sounding so phaselicious, while the dance thud of a kickdrum has real timing and impact. As for jazz and classical material, they approach the realm of the Sennheiser HD 800s, ruthlessly revealing inconsistencies and flaws, putting any hiss in old recordings a little to the fore, but portraying instruments across and fore/aft in an immaculately separated soundstage. There’s a very light reediness to upper registers which we suspect will sweeten as you move up Stax’s range (see below), and we noticed the padding against the ears can start getting a little sticky on a warm day. Small bones against a beautiful body of sound like this. 

Stax today may not be a direct continuation of the Stax we knew in 1990, but the signature sound remains, and we fell in love all over again with the electrostatic headphone concept. In addition to this pairing, the Stax range also includes SR-307s ($699), SR-407s ($849) and SR-507s ($1399, with higher level amps also available (including the valve version) up to $3699. That boringly-round SR-009 reference earspeaker with its valve amp would come in above $10,000. Bring it on, we say.

[Prices correct at August 2015.]