Stax SR-001 Mk 2 Headphones Reviewed

Published On: January 11, 2009
Last Updated on: October 31, 2020
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Stax SR-001 Mk 2 Headphones Reviewed

Stax has a reputation for making products to suit the discerning audiophile. These are no exception. Described by our reviewer as "the best value high-end headphone in the universe," the Mk2 is "more appealing in overall naturalness" then it's highly regarded predecessor, the Mk1...

Stax SR-001 Mk 2 Headphones Reviewed

By Author: Home Theater Review
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Oh, me of little faith. Worried as I was that Stax, that great Japanese purveyor of no-compromise, high-end headphones and Keeper Of The Electrostatic Faith, might have left us for good, I never really expected it to come back so, so . As if to belie the downturn in the audio business, the erosion of the Japanese economy and whatever else plagues us as this century ends, Stax has turned up with two of the most saleable products they've ever issued.

Additional Resources
Read a bunch of other STAX reviews from here.

SR-001 Mk 2
Back in '94, prototypes of Stax' dinky in-the-ear headphones - the world's first teensy electrostatic cans - appeared, but it wasn't until late '96 that a pair arrived for review. I called the SR-001 and its SRM-001 energiser "...the best value high-end headphone in the universe." More to the point, it sold then for "a sane £279.95", still a price to respect, given the sound quality.

In new Mk 2 form, the only visual give-away to upgrading is the leather-like cushion on the headband. Otherwise, it remains visually and operationally identical. Open the same, paperback-sized carton and out pop the same 'little jewels certain to elicit cries of "Gimme!!! Gimme!!!" from any audiophile with a love for miniaturisation'. As before, a steel strip connects the two freely-swivelling earpieces, still able to slide over two inches to ensure that they'll fit any size of cranium.

Competition and Competition
If you are interested in comparing the Stax SR-001 Mk 2 against other headphones, read our reviews for the Sennheiser HD 205-II and the Bowers & Wilkins P5 mobile hi-fi headphones. You can read more reviews in our Headphone review section. Also, there is more information available on our Stax brand page.

Added padding aside, what's changed is the 5p-piece-sized electrostatic driver. In the Mk 2, it's substantially lighter because the diaphragm has been reduced from 2.5 to 1.5 micron thick. It remains visible through the pivot on the end of the earpiece, a cup which measures 28mm in diameter. The portion entering your ear is the same 'horn' terminated in silicon rubber surrounds and which you insert as far as their 15mm taper allows. As I wrote before, this is the key to successful use of the SR-001 because incorrect insertion means reduced bass, messy treble and 'a complete skewing of the images'.

While the reduction in the diaphragm thickness means increased speed and better transients by virtue of weight loss, it's not so as you'd notice it by hefting the new and the old; the earpieces still weigh only 12g and the assembly is no more unobtrusive a weight on one's head than a yarmulke. The element is still classic push-pull electrostatic, with the frequency response of 20-1kHz (+/-2dB) and 1kHz-20kHz (+/-4dB) unchanged. Because the SR-001 Mk 2 is powered by a dedicated energiser, the other specifications remain academic: capacitance is 44pf with the 1.5m long, 6-core, OFC cable, 17pf without; impedance is 360k ohms/10kHz; sensitivity is 111dB/100Vrms/1kHz; bias voltage is 580V DC. Note, too, that maximum SPLs available are still 119dB at 1kHz. Ouch.

For those who will use the SR-001 Mk 2 for its true purpose - high-end performance from personal hi-fis - note that the battery-driven the 60x24x120mm (WHD) SRM-001 weighs 140g with a pair of AA cells, good for 2-5 hours use. Any 4.5V/300mA mains adaptor can drive this at home, to save on batteries. But - you listening, Ben? - this sounds better via batteries rather than mains: cleaner, quieter and a tad more dynamic...believe it or not. (By the way, there is a version of this headphone called the SR-003, which comes fitted with the necessary 5in plug to fit a Stax 'Pro' input on a full-blown Stax energisers.)

Because this device only works with the SR-001 headphones, it must torment users of other Stax models to learn that the company has produced in this teensy chassis an energiser with a frequency response of 5Hz-20kHz (+0/-3dB @ 10V RMS output), with gain of 54dB, distortion of 0.1 percent, and an input impedance of 10k ohms. Its side panel carries a stereo 3.5mm socket to take the a line-level signal, and the front bears the socket for the headphones. Operation is via a nicely damped, combined on/off-plus-volume rotary. Next to the headphone socket are two LEDs, a quickly-extinguished red LED to indicate switch-on and settling down, and a green LED for normal operation.

Alas, the SR-001 Mk 2 still uses the flimsy, non-standard connector. Stax fitted a rubbery female connector which grips the end of the internal circuit board. The 'U'-shaped socket prevents fitting the lead incorrectly, reveals what is simply a corner of the PCB. But I am pleased to say that the Mk 2 seems to grip more securely than its predecessor.

And it is still, by my reckoning, the best value high-end headphone in the universe. No, make that better, as the price has been reduced by a tenner to £269.95. I ran both new and old off my Walkman Pro, Roksan's Caspian CD player and my computer's Soundblaster 64 AWE soundcard. It is still 'a truly comfortable, full-range, transparent, lush transducer which you soon forget that you're "wearing", but the Mk 2's improvements were not where I expected them. Instead of sweeter, faster treble, what I heard was...knock-out bass.

Read much more on Page 2


No kidding: the Stax Mk 2 seems to go deeper, it's certainly richer and there's a better sense of weight. It will, however, seem a bit alien if you're moved to the Mk 2 from a long period with the Mk 1, because the bass gains alter the whole tonal balance. The Mk 2 strikes me as slightly less clinical, and marginally less detailed but certainly more appealing in overall naturalness. And I swear, given that the comparisons were made by swapping headphones while using the same energiser, that the new version is more sensitive and discernibly louder when the volume control remains at a fixed position. I set the control at the 12 o'clock point and swapped the cans again and again, and I'm certain that the Mk 2 delivered more level. Either than, or they demonstrate what is the headphone equivalent of being 'in your face'. Or, more precisely, behind it.

It is with deep relief I report that the Mk 2 betters the Mk 1 in enough areas to warrant the new suffix. But not enough to make you want to ditch a pair of the earlier ones. Rather, I look at this as more of an incentive to 'go Stax' on the cheap for those who have never sampled Stax cans. But it's not the only incentive...

Somehow, the 'new' Stax organisation has managed to make a pair of 'proper' Stax headphones, in this case a version of the rectangular-earpieced Lambdas, available energiser for 399.95. Yes, you read that correctly. The Lambda Nova Basic is a headphone which appears to differ from the dearer Signature and Classic versions of the Lambda Nova only in the areas of cable type (OFC instead of PC-OCC) and cushion material. That aside, it's a full-range, open-back electrostatic design which surrounds the ear, delivering 7-41kHz frequency response and 100dB SPLs. Weight is a tolerable 457g with cable, and the comfort level is as high as it was even with the earliest Lambdas.

Cost-cutting comes in the form of the SRM-Xh energiser, a tiny (132x38x132mm WHD), solid-state device which offers an output for only one set of headphones, an on-off rocker switch, rotary volume control and a pair of phono sockets at the back to accept a line level signal. It runs off a wall wart and delivers 280V RMS to drive either Lambda Novas or the SR-003s.

Let's be perfectly frank: you shouldn't listen with the SRM-Xh trying Stax headphones with any of the dearer energisers. You will hear immediately why some headphone users are prepared to drop 995 or 1295 for one of the valve units, or 479 for the Class-A solid-state SRM-3. Quite blatantly, the dynamics improve, especially the speed of swings from soft to loud, the bass extends and the between-note silences become blacker than Omas ink. Which isn't to say that the Lambda Nova Basic package is compromised enough to cause worry; let's just leave it that you'll be back to your Stax dealer's as soon as your funds will allow you to upgrade.

But straight out of the box, the Lambda Nova Basic system is an absolute joy, the closest I've ever heard to four-figure Stax performance below a grand. And yet we're talking wa-a-ay below a grand. The sound is bigger and richer than even the direct-injection from the SR-001, with the delicious out-of-the-head sensation which make open-backs preferred by every headphone user who can get away with non-isolating earpieces. But because only traditional, clamp-your-head types can offer better bass because of the seal made by cushion-to-head, open models like the Lambda must accomplish the same with a larger diaphragm. So, yes, you look like a real asshole wearing these things, but hey - that's a small price to pay for such convincing, speaker-like performance.

What bigger Stax systems like the Lambdas and the still-king-of-the-hill Omegas offer to headphone users is scale as close to that of speakers, given the shift in soundstage from in front of you to inside your head. Once you've accepted that spatial oddity, and you can focus on the sonics, you realise that headphones give you the most direct, detailed and precise entry the sound than any other sort of playback system. What the Staxes have always excelled at are openness and transparency, with more than a semblance of bass and a proximity to actual neutrality good enough to make them reference-grade tools. The Lambda Nova Basic, minimalist energiser included, sacrifices only tiny degrees of excellence vis a vis the dearer models while saving a ton of money. For the bass and openness alone, most headphone users will find it unable to resist a pair. And when you hear vocals so lifelike that you look over your should in surprise, well, all you can do is whip out your credit card.

With apologies to Sennheiser, Grado and other purveyors of fine - no, make that dynamic headphones, I must state: anyone spending above 398 for a pair of headphones try the Stax Lambda Nova basic package. The electrostatic experience, especially for transparency and 'virtual' freedom from headphone constraints, so categorically trounces conventional cans that I can find no justification for the latter above a certain price point. By being so coherent, so competent and so free of glaring weaknesses, the Lambda Nova Basic has determined that very price.

Stax is back. Make no mistake. But who'd have thought that the return would be a complete denial of inflation?

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