Stax SR-007 Mk2

The SR-007 has a long history among the Stax and electrostatic enthusiasts as being one of the greatest headphones in the world. I've been in the hobby for 14 years and they - with a few changes - have been a staple of any discussion about electrostatic headphones. Yet the reviews are sparse and attention is more frequently on new upcoming "Stax killers" and "best Electrostats ever". This is certainly a shame, because the SR-007 is the most enjoyable, high quality headphone I've heard. I had the opportunity to hear the X9000, Audeze CRBN, and Dan Clark Corina and I would still opt for the SR-007. For $2200 all told it is by no means a cheap or affordable product, but against other headphones 2x the price it stands very strongly.
For reference, I use a Mjolnir SR-006tA amplifier connected to an Audio GD D-27. I've been using them since February 2023 on a variety of genres, but mostly heavy metal and jazz. My set are completely unmodded and were purchased new from Woo Audio. I understand the blue tac mod is often recommended to remove the mid-bass hump and make the signature more linear, but I am not opening up $2200 electrostatic headphones.

Comfort and Design
Like most electrostatics, the SR-007 is very lightweight. The design is very simple: black leather suspension headband, black cups, black ribbon cable, gold grills. It's heavier than the X9K and the overall design seems less premium, but that doesn't matter once they're on your head. I can spend hours listening to my Stax without issue. The suspension strap works well, but I have never seen another headphone use rotating cups. My knowledge of earcup design is by no means absolute, but as an engineer I can say a unique design is not always best.
Soundstage and Imaging
Electrostatics possess a unique ethereal image which places instruments in a realistic space. Nothing blends together nor do notes seem small; sound comes to your ears like smoke wafting from a fire. The imaging is not as precise as the HD800S nor is the image as wide, but it feels more accurate to the atmosphere of the majority of music. I can focus on any one instrument and obtain a complete picture of the song or piece. The texture of music is phenomenal for this reason and lends an extra dimension. I have a condition called synesthesia, specifically that I perceive sounds with color and density. Heavy metal blooms with hard edges of aggressive death metal while string music rides on peaks of green glass. To experience music with headphones like the SR-007 is to obtain a fuller, more memorable picture.
Bass
The quality of the bass is top notch and the quantity is perfect. I wasn't prepared for how strong the bass was since my only prior experience with Estats was the ESP-95X. The LCD-3 certainly has greater impact, but the combination of estat naturalness and SR007 power makes bass-heavy music all the more pleasing. Tracks like "The Fire of Resurrection" require fast, aggressive response without getting lost in the chaos. On the Stax, such music is handled beautifully.
Mids
Vocals are beautiful, intimate and perfectly balanced. Diana Krall is euphonic and sweet but not in a way that seems artificial. Avi Kaplan is rich and full bodied while Heilung is soft and ethereal. Vocals are poured from these headphones like a glass of Elijah Craig. By far my favorite vocals from this headphone are any song by Scar Symmetry. If the HD-800S was made for Diana Krall, the Stax is made for Scar Symmetry.
Treble
Never sharp, never fatiguing, and always fantastic. Not a single song is excessive or unpleasant, no matter how poorly recorded or sharp the highs are. Bright music sparkles instead of burning. As with the mids, the highs on Scar Symmetry are played beautifully.
Conclusion
The Stax SR-007 is my favorite headphone and my current endgame. When I started getting into high-end headphones, my dream set up included an electrostat but I didn't know how good music could be until these headphones. They have a darker signature than netural but that never detracts from the music. They are power hungry as I'm told, but with an SR-006tA I get plenty out of the music. I don't know how long Stax will continue making these beauties so scoop them up if you have $2200 burning a hole in your pocket. You won't be disappointed.

This review is for the latest iteration of the Stax SR-007mk2 which has been dubbed the 007mk2.9.
The pair I review is my own and has not been modified.

I have had two pairs of 007mk2; one bought some time between 2016 and 2019 and one brand spanking new, purchased end of 2020. Both headphones did sound identical to me but I felt the newer version had a better feel build-wise.
Perhaps that is due to the fact that one of them was worn and the other one was new.

I kept the 2020 version (SZ3-22xxx), which is the version I will refer to in this review.


(note the Dakoni Nuggets I added so they would fit my small head)

Build


The SR-007 mk2 is a well built piece of equipment. It looks and feels high-quality, that is for sure. The ear pads are mhm-mhm soft. Some may not appreciate the rotating ear cups, a feature I don't fully understand myself.
The entire ear cups (not just the ear pads) have the ability to freely rotate, allowing for some degree of adjustment. This would make sense, because the ear cups are thicker on the bottom than on top and would allow us to adjust the fit by rotating the cups.
However, this feature is negated by two facts:

1.- I am an OCD monkey and couldn't live with my stupid ass if the cable wouldn't point straight downward
2.- You can just as easily rotate the ear pads themselves instead of rotating the entire cup for the same effect

Nevertheless, the build quality is great and the headphones do feel solid. I strongly prefer the build of the SR-007mk2 over the SR-009, but that will be a matter of preference.



Fit

A second eyebrow-raiser is the fit, which solely depends on the ear cups just happening to have the correct angle for your head. While the cups can rotate freely, they can not pivot. Fear not, fellow apes! I did not find this to be a problem. Fit, width-wise, was excellent.

I do also have a small head, apparently. I always use the smallest setting on a headband and a pair of SR-009 barely fit me. That is why I purchased a set of Dekoni Nuggets. These work wonders and the SR-007 mk2 fit my head only by virtue of these nuggets. Now, however they fit and feel very, very comfortable. Lovely.



Amplification

I can only comment on the sound of the mk2 paired with a High-Amp Alpha Centauri V9.5.
This hybrid tube amplifier outputs approx. 400V, so even though it is a big boy, it is not a big boy.
There are some concerns as to how to amplify the 007 properly which I can not comment on. This pair is driven by the above mentioned Amp which can be purchased for as little as 1.600€ in Germany, thanks to high-amp.

As you can see, normal listening volumes can be achieved with plenty of power to spare.





Comparison

I have been listening music with a L300 limited (driven by a Stax 353x, followed by the Alpha Centauri 9.5) for a little over a year now, so this will be my main point of reference. I have also had the chance to get personally acquainted with a pair of SR-009 in my home setup and had the chance to listen to the l700 and l700 mk2 during gatherings.

The l300 limited, L700 and 009 are surprisingly similar. They all share an ethereal quality which, I assume, is now associated with the Stax sound signature. All of the above err on the cold/analytic side of neutral with the 009 arguably being dead on.
I have loved the l300 limited for its slightly raised mid-bass response and ever so slightly warmer tonality in comparison to the 009 but acknowledged the almost dead-center neutrality and brutal transparency of the 009.
But even the l300 ltd were so revealing, it was sometimes painful.

Detail is a fickle thing and too much can easily be jarring. The l300 ltd and 009 were not bad in any way or annoying but also not relaxing and round.

Flavour

I was immediately surprised at how natural and organic the 007mk2 sounded. I internally labeled this as: neutral-warm. Imagine all the Stax qualities you are accustomed with and add a layer of warmth and uuumph to it. That is basically the signature of the 007mk2. Don't mistake these for being bloated or restrained. We are still talking Stax here!

Speed

I was concerned that this would come at a price of slow decay or sluggish highs, but no no no.
The 007 is a precision instrument with lightning fast transient. Things happen left and right, up and down, front and back.
I have not come across a song that was too demanding for these headphones.

Soundstage

I was also concerned about the admittedly intimate soundstage as opposed to the seemingly unrestrained width and height of its more ethereal brethren. To my pleasure, the soundstage is much more coherent and thus spatial clues can be put into context much better which in turn makes it easier to locate instruments with pin-point accuracy.
The 007mk2 can be wide and it can be close. In your ear, or far far away.
I was also pleased to hear the soundstage, while not as earsplittingly high goes much deeper.

Combine the instant speed with the ability to locate and you have yourself a WOW experience.
Before you smell it, you will not know for sure if a fart was yours or part of the song. It's that realistic.



Bass

I was expecting the 007mk2 to have a little emphasis in the bass region which is exactly what was delivered. The lower regions are certainly elevated or more pronounced than the rather linear and perhaps boring 009.
You can imagine the bass of these headphones as what Stax, a company not being known for having a close relationship with bass-heads, thinks bass might be.
I would describe the bass as being both dry and juicy. A little more juicy than the 009, but far from being yucky.
The bass, in my opinion, is still just under neutral when compared to other types of headphones.

You will not get teeth rattling bass. Nu-uh. What you will get is an extremely layered and textured growl, though. This works particularly well with string instruments but can also produce a hump if it must. The depth is amazing and you can easily feel it in your chest. What is also amazing about the bass is its quality which is detailed and layered and well integrated into the rest of the music.

Midrange

The midrange is important for me because I enjoy vocals. The l300 limited and the 009 both were excellent in that regard. They both hide nothing. In direct comparison to the 009, the l300 limited lacked smoothness in the higher midrange. Not a difference I would call extreme, though.
The 007mk2 is a little smoother here. Vocals definitely feel a little more smooth and emotive, more "golden" but also less forward and more integrated. Details like lip smacking, breathing or even hissing is still present and can be enjoyed but is not in your face. I appreciate that.

It's a little like:

MIXING FLAW!!!!! -SR-009

Mixing flaw -SR-007

Highs

This is where the 007 gets interesting. There certainly is a roll-off in the highest highs which prevent the 007 from getting piercing quickly. Do not misjudge this statement, they will pierce your ear if they must. Percussion instruments that are mixed to have too much presence will hurt your ear at loud listening volumes as if they were struck right beside your head. This lends the 007 a very high dynamic range making them sound very... dynamic.
Most of the time, for the vast majority of decently mixed music, the 007 will never pierce or hurt. Which is not something I can say for the 009 or the l700 / l300 limited.

The highs, while crystal clear, have just a touch of golden shine and are so frivolously jovial and detailed as pixies dancing around in the night. There is no opaqueness in the highs that will prevent you from enjoying them. At the same time, you're not afraid of them getting offensive for no reason (MIXING FLAW MOTHERFU***R).

Final thoughts

This headphone/ these ear speakers are a beast. They feel like large speakers strapped to your ear for your listening convenience.
They render music expansive and lifelike, authentic and sparkly, emotional and detailed. They are a friendly kind of beast and will not offend you for no reason, but they will also not hide things from you.

The only way I can truly describe them is beautiful. I find myself wanting for more. When previously I had enough after 30min., I can now listen to a whole album without strain.

Yeah, yeah... bUt ItS nOt NeUtRal.
To that I say: Neutral - Schmeutral!

I am not interested in your false beauty standards! Real frequency responses have curves!
Honestly though, the 007mk2 vs the 009 dilemma is the same as the thin blonde super-model vs. the lovely brunette with boobs (or chest hair. Whichever you might prefer). The image I'm trying to paint here is that the SR-009 and SR-007mk2 are both pretty much perfect representations of a breed of headphones, separated not by technical superiority but by personal preference. What is it going to be? Cold-Neutral and detailed? Or Warm-Neutral and organic?

I am a relative novice in the world of Stax. However, after almost a year of bliss, I have decided that I have heard enough to offer some impressions of some of the Stax cans I own. I have done a review of the Stax SR L700 as well as the top notch but fussy SR-009. I thought I would finish up my series of reviews by setting down my experience of the previous Stax flagship, the well-loved but slightly divisive SR-007.

Whenever and wherever there is a discussion on the Stax SR-007, there will be a divide between proponents of the much cherished MK1 and the current production MK2. Of course, the divide is really premised on slightly different tuning of the two versions. I have no skin in the game as I am fortunate enough to own both. So, any arguments of superiority or advantage inter se matter not to me. For the purposes of this review, however, I will primarily focus on the current production SR-007 Mk2, which is often referred to as the MK 2.5 to differentiate it from the first iteration of the much vilified initial production of MK2. It could take almost an entire thesis to debate the failings of that version, which admittedly I have not heard first hand. Suffice it to say that the oft-repeated complaint was that the mid-bass hump introduced with the advent of the SR-007Mk2 was clumsily done and as a result, the mids were muddied and it introduced incoherence to the resulting sonics.

As pointed out elsewhere as well, Spkrs01 and Anakchan have been absolute gems in fielding an endless stream of questions from a curious mind, as well as bringing me quickly up to speed to what has transpired in the past in the timelines of the development of Stax and their cans. The most valuable counsel from both has been the consistent mantra: have a listen yourself. That I find all too true when today opinions are offered which are not necessarily based on first-hand experience and without the context of the systems in which the listening was done.

It may be a little unusual but my little voyage into Stax territory began at the top with the SR-009 and the much sought after SR-007 MK1. I have since added the SR-007 MK2 and the SR L700 to my cosy Stax collection. I currently also have a few non-electrostatic cans: most of the top tier Grados, the LCD 2 & 3, HD800, Hifiman HE-6, HE-5LE, HE-560, HE-500, HE-1000, Fostex TH900, AKG K702 & K812, the Final Sonorous X and the Abyss.


Home Desktop Stax Set Up

My Stax set up comprises an Auralic Aries (with external linear PSU), connected via a Audiquest Diamond USB 3 cable to a Bricasti M1 DAC and then a pair of Tralucent Uber balanced interconnects to the Cavalli Liquid Lightning 2, and then pass through to the VAW 8PS via a pair of Toxic Cables Silver Venom balanced interconnects. Power cord for the DAC and the Liquid Lightning 2 is a Tralucent Uber power cord, while power to the VAW 8PS is supplied by a Tralucent Silver/Gold power cord. Power to the components of the desktop rig and sources is fed through an Isotek Aquarus and all the power cords use US plugs. Mains power is fed to the Isotek Aquarius via a Tralucent Uber power cord.

My Synology DS 414 and a Seagate Backup Plus HDD (connected directly via USB to the Aries) are powered by the new Plixir Elite BDC Power Supply kindly customized for me by James Soh of Sound Affairs, Singapore. At the advice of James, I run a separate switch for the audio components away from the wifi access point. The switch is also powered by the same Plixir Elite BDC Power Supply. The Aries and the Synology DS414 NAS are connected via the dedicated switch by a pair of Ranko Acoustics OCC audio LAN cables.


Build Quality

The build quality of the SR-007 is very good. I get raised eyebrows whenever I say this but I frankly prefer the headband of the SR-007. I find it more comfortable and I really enjoy being able to rotate the ear pads for my liking.

My SR-007 MK2 is the export version which is all black.


Comfort and Isolation

The ear cups of the SR-007 fit my ears well. The quality of the lambskin on the ear pads help create the great sense of comfort and luxury whenever I slip the SR-007 on. The grip or clamping force of the SR-007 is also not too tight, though slightly tighter than the SR-009. It is nevertheless still comfortable and sufficiently secure. As with the SR-009, the SR-007 is surprisingly light in my hand and on my head. If you struggle with the weight of the planars from Audeze or the older Hifiman range, you really have to give Stax cans a try. You will be impressed.

The Stax SR-007 is an open can with practically zero isolation. You can’t have your cake and eat it: the airiness and sense of space you get in return is well worth the lack of isolation.


Music Genres

The last time I checked on JRiver Media Centre, I could run my music collection non-stop for almost 2 years. That gives you an idea of how much there is available for my listening pleasure. In the two years of listening, you will come across most genres from medieval church vocals and classical music all the way to acoustic vocals, modern jazz vocals and most of types of pop music, international or regional.

Because of the tonality of the SR-007, being on the warmer side of the SR-009, it is actually very easy to listen to most genres of music. Frankly, I cannot say I can recall any type of music I have heard on the SR-007 where I winced. It is actually very good with EDM. I love Blame by Calvin Harris featuring John Newman on the SR-007: lovely pulsating bass line and so quick. On the other hand, it shares the mastery of female vocals like the SR-009. While not offering as clear a glimpse into the souls of the singers as the SR-009, it can nonetheless be breathtaking. Spkrs01 was absolutely right about the magical quality of the Omegas with female vocals. Though, of course, I have yet to experience the incontinence which he suggested will come with the enthrallment.

I am happy to say that the SR-007, while being really quite transparent, is much more forgiving than the SR-009. I suspect the warmth of the SR-007 helps mask shortcomings in the music quality.


Sound Quality

What is clear is that the SR-007 is darker in tonality than the SR-009. Those who find the SR-009 too neutral or transparent to be enjoyable may prefer the SR-007.

Of course, even with the darker tonality, the trebles of the SR-007 are what you would expect with a Stax Omega: extended, clear, pristine and smooth. It may not be as in your face as those in the SR-009. This is because of the more present bass in the sound signature of the SR-007. Nonetheless, Alison Krauss still sings with the voice of an angel. With lesser cans, with the presence of more bass, Alison may sound more womanly. That would be coloration or distortion. It is testament to the treble credentials of the SR-007 that Alison Krauss’ voice is still as plaintive and lilting as it is on the SR-009.

In the realm of mids, the SR-007 might be preferred by some to the SR-009. Whilst the texture, timbre and soundstage witnessed with the SR-009 are present, the added warmth makes everything more 3D. Everything is fuller. Whether this is a good thing or bad is a matter of debate. For me, as long as it breathes life into the music, I am happy. Female vocalists are wonderful and the nuances and emotions are well and delicately conveyed. What is notable is that vocals and music from the 50s and 60s sound fuller, less brittle and a whole lot more listenable. For example, Dionne Warwick sounds astonishingly good in her earlier albums.

While the bass of the SR-007 is never going to come close to the visceral bass of the SR-009, it is a whole lot more present than that in the SR-009. It possesses quality as with its younger sibling, but injects quantity as well. The SR-007 has easily the most impressive bass in the entire Stax range of cans. The other thing which the darker tonality adds is a more organic sound signature.

I frankly think that the SR-007 is much easier to love for most persons and is much more forgiving (than the SR-009) of less than well recorded and mastered music.


Pairing

The SR-007 is not an easy can to drive. I think of my little collection, the SR-007 is the one which is most difficult to drive. Hence, it thrives on the driving power of the Cavalli LL2 and VAW 8PS. While it is never going to be as transparent as the SR-009, nonetheless the differences in character between my two amps are nonetheless apparent: the slightly languid presentation of the LL2, while the VAW is more energetic and forward in its presentation. Regardless, both pairings are musical and afford me hours of listening pleasure.


Sidebar: SR-007MK1 vs SR-007MK2

As alluded to above, the most divisive debate in the Stax world (other than between SR-009 and SR-007 adherents) is the relative virtues of the two iterations of the SR-007. I own both and hence it matters not who is right or wrong. This may be a bit simplistic but the divide is between the cleaner leaner mids of the MK1 and the fuller mids of the MK2. Here, I am talking about the sonic differences. The discussion about what causes this is another topic which can take up pages upon pages of discussion in forum threads. Is one better than the other? All I will say is that in the ultimate analysis, it boils down to a question of preferences which are necessarily personal in nature. I shall leave at that.


Conclusion

The SR-007 is a wonderful creation from Stax. One forgets that until the advent of the SR-009, the SR-007 ruled the roost and easily one of the best, if not the best, headphone around. It is less demanding and more forgiving of the music it is fed. Its more organic signature may also be easier to love.