The Stax I thread

I haven’t A/B the x9000 with 007mk1/2 but, from past experience, the only thing in common would be the warmer tilt vs 009. For the rest (resolution, evenness of treble, layering) this for now feels more like a refined 009 than a walk back to dark ages lol.

Mind you, I liked the 007, owned both mk1/2 variants and used BHSE to drive it but never got to enjoy it as much as the cult following suggests. Maybe just a matter of taste.

As for price/performance, a well driven recent 007mk2 (with newer pads) is probably much better value. Myself, I’m totally out of headphone world and back to 2 channel so I am not the right person to probe about value of TOTL headphones hahaha.

 

Doesn't seem like it, there is an impression from a 007 owner: "I brought my SR-007MkI along with me for comparison and the SR-X9000 sound signature leans more towards the 009S in tonality. The SR-007MkI is considerably warmer, soundstage is narrower, less precise and is less resolving though the warmer tonality makes it more of a complementary headphone to the SR-X9000."

Of course, having to use the T8000 for these preliminary impressions is far from optimal.

 

Having heard 009S and 007MK2 recently I can appreciate this voicing! The real question is how X9000 will compare to CRBN

An I don't think any one has heard both out of an optimal system yet

 

So I've been comparing this loaner KGSSHV amp (onboard version) against my modified 727.
First impression after 10+ years with Stax amps (besides thinking: "Wow, this is huge and heavy!") was: "Wow, so much power!" The increase in dynamics, bass control is very noticeable, notes have more weight to them, all my Pro bias headphones sounding more alive more controlled, less compressed. Basically, it starts levelling up the general disadvantages of electrostatics. But of course they will never be orthos and vice versa, very good explanation on the Audeze site [here].
I am hearing details in bass lines with the Omega which I haven't heard before, better separation, heard statements it is "unfocused" which do not seem to hold true anymore (I would say that for me, focus and separation mean different things, but anyway).
The greatest compliment I can give is that it makes me enjoy listening to music, especially pop or rock.
Also seems to have a more neutral sound, I expected it to be bright, but it isn't, it is the Stax amps that seem to have a warmer, sweeter tone with a bit more mids and less treble, exaggerating differences between them (without the midrange I can hear bass more cleanly on the KGSSHV) I have tried to level match using an SPL meter (got pretty close by ear), but the Stax amp will feel ever so slightly louder because of this (or if I try to correct that, then there will be opposite differences, affecting subjective judgement), maybe against something like a 323S it would have been a bit easier.

However, what I also noticed is the spatiality. Expected the soundstage to be less deep, but the presentation is kind of rough-and-ready, which means on acoustic music, especially on the T1W amp (which I generally preferred over the 727), I can hear the instruments rendered 3D and gently moving in space, I am not hearing that with the KGSSHV, that seems to be quite a big loss with the Omega.
This is something I've read before on two old comparisons, 717 vs KGSS (you can say older, lesser versions of these) one saying the latter was not as good in low-level detail.
Has anyone else noticed this? A deliberate tuning choice by Stax for their headphones and a by-product of that? Is this something I can expect to gain back with a BHSE or similar?

I also don't think the advantages of an amp like this need high volumes to show, at low volumes I could hear Stax amps sounding a bit 'dead' to me, so I pushed it higher anyway, but congestion is apparent at any volume, if that type of music is what's on the playlist.

Big shout-out to the 'blue-collar worker' Gamma Pros, ever since I got my first pair from Ogodei here, always loved them from the start, but the raw delivery suits the KGSSHV's favourite genres perfectly, great combo, still warm (one would say over the top bass, not enough treble and extension) but more clarity, punch, control, speed and dynamics, musicality and smoothness kept intact, maybe reminds me of vintage orthos taken to another level? It's a pity they seem to be so fragile compared to other Stax headphones with that exposed dust cover, that pair and another have been away from some time for a full repair, both with the same issue.

The Lambda Pro, Gamma Pro and of course Omega act like they are just 'getting started', commanding more power.

Also got a 009 loaned to me as well, heard it a few times before and I am not as enthusiastic. Driven very well with surprising bass punch, but this amp won't try to hide tonal issues. I would say better than a Stax amp, taking heat off the midrange by a tad, adding more to the treble instead. I can imagine someone love them on first listen, I just don't enjoy music this way. I am sure R2R DACs, tubes or the supposedly warmer Carbon would make it better, but seems far from ideal, the Omega still lacks bass control and impact (but fuller and deeper than the 009, on rare occasions hot in the treble at high volumes), but more natural sounding, able to dive deeper into the music itself instead of hiding it under a voile of added clarity.

 

KGSSHV sound is a bit 'heavier' (more low-end fullness + slower decay throughout) than the Stax amps I've heard so yes, Ive noticed that. BHSE will still be fuller than the Stax amps but its bit faster, it will bring back more of the 3D quaility but its still not as lean.

Yes, I had that experience with most Stax amps, at low volume the entire experience is a it bit flattened.

The R2R DAC helps the 009 on the KGSSHV some; the Carbon does not. The 009 is a favorite with the tube warmth of the BHSE or the Megatron, on the KGSSHV its a bit lean. The 007 or L7 on the KGSSHV is about the best 'musical' headphone experience I've ever had.

 

Speaking of best musical headphone experience: this time, I've decided to put the song Cat Stevens - Morning Has Broken on repeat (multiple tracks can overwhelming for me), switching back to the familiar T1W with the DA11 so that I can test all Staxes. This recording has 'perspectival air', a term used a lot in darth nut's old, extensive reviews, but since it has been forgotten (Omega1 vs Omega2 written 21 years ago, would you believe it)

Here are my personal rankings, backwards to forwards:

6. SR-009
Deeply sorry, my ears/chain has to be faulty, but this is unnatural. Great detail overwhelmed by a glossy tone, sharp sounding with too much focus on the guitar plucking. There is a certain gentleman owning (or owned) basically every Stax ever made, and he observed that after the introduction of the SR-507 in 2010 the spatial rendering of the newly developed models changed significantly (and that the SR-X9000 has finally made the necessary step backwards). Not that familiar with the rest yet, I can only say that I agree, the stage and holography are just not rendered very well.

5. SR-Gamma Pro
Last time I've praised it's liveliness with old rock, feels just as home at home playing smooth, mellow music, much more than a one-trick pony. Sounds dark and soft here (not matched to the amp) but airy, non-veiled might be the fatiguing I've ever heard. I feel a bit bad for putting it here, because on the vast majority of occasions, it manages to steamroll two of our other candidates here, having some similarities to the winner, imho a much darker version of that style with better bass and speed. Comfort isn't as good though, some people with different ear shapes probably wouldn't like it much.

4. SR-Lambda Pro
I tend to be either annoyed or amazed, this time it's the latter. Manages to counteract the softness of the amp very nicely without the treble bite it has a smooth frequency response with a nice spacious sound and surprisingly good, weighty piano. Has a lot of nice estats traits. When set up well, I would say a bit of a bargain, others might criticise it for sounding harsh at times, too diffused and not as musical as others. Some say there is a late variation called the Pro Classic or Sprit supposedly the same thing without the damping, this almost fully original piece seems too minty to tamper with.

3. SR-Omega
Might be surprising. By far the most 'exquisite' sound of the bunch, this recording plays to its advantages. Supposed to be the perspectival air champion. It is. Bass sounds more sophisticated (badly limited by power at least has synergy), phenomenal inner, unforced detail. However, I can't help feeling that it has slightly too much of that laid-back approach and this is something I can still detect with the KGSSHV, although it is a lot better, I loose the airiness. A lot of people said it can sound close to the HE90 or even surpass it, I wish it (or the 009) were like that, some even say there are different versions, almost impossible to find out with something this rare and old, as-is, this seems substantially different. Probably very picky about everything, but after some self-calibration it can be very captivating. Not that anybody would by one with its issues, only recommended if listening also in darkness and silence, that way it can show what it's capable of.

2. SR-X Mk3
Being the cheapest, most entry-level one, a total shocker (also acquired from this forum, have another one which is not as good, also undergoing repair). Can be punishing sometimes, limited in extension at both ends, but here it is simply the most faithful representation, eliminating most of the colorations created by the earflaps, whether one finds those more natural or not, maybe a bit dry (certainly would not want to put it on solid-state) but interestingly in that narrow hall, it manages so reveal some depth information like the Omega. Used to hate the comfort, with these velour pads it seems passable. Not ruling out a Pro version for the future (not that I need any more, issues will remain, but much better...)

(drumroll intensifies...)

1. SR-Lambda
(Disclaimer: 'golden sample' out of multiple copies, none of them sounds bad in the slightest overall)
It has been said before here as well in the [Stax Compendium], a fantastic all-rounder. I just don't quite get why people don't tend to rank it much higher, because for me, it combines so much of what others do, and just hits that sweet spot, feels like coming home. Nothing seems to be hyped, has a lot of natural transparency and detail that others mask, not possessing the same level of overall balance. Nearly SR-X levels of accuracy, does flavour it with a but of smoothness just to make it more musical, sounds clear like the 009 but also soothing like the Omega. In fact, I would put it right between them, not really leaning towards brightness or warmth, clarity or laid-back, just very clean. Limited by frequency extension just a tiny bit, but somehow makes it sound even more pure. Nothing, but the essence of the music. Yes, the bass is far from the best, I wish it could be merged with some of the advancements of the Pro at least, but this just reminds me of how HE90 'sings', rather than 'plays', where I feel most things 'clicking' and it wants to bring a tear in the eyes, only the Omega can do that, only after I accepting being 'cheated somewhat' and fully immerse in it, not on first listen. Just because it is efficient, it does not mean it is not being held back badly by the amp (like all others), I am thinking maybe a DIY HEV90 might do decently here, it can have a tendency to sound thin (but never really offensive), but maybe a solid-state amp could do the job as well, if it is warm enough. (have tried it with a feedback modded 727 with NB output, leaner, brighter, thinner but smooth and musical as always) Very nice pairing with the SRA-3S amp as well.
I have been recommended a HE60 a few times before, worried about the thinness (build...) and the bass, which, for the most part is actually quite well balanced on the Lambda, just somewhat low quality, some possibilities with damping removal might apply here, too.

I've probably observed more while playing, forgot about them in the meantime, was hoping that doing these tests would help me play the elimination game with some of these headphones, seems to achieve the opposite (after [reading] the Signature being compared against the NB, I had to get a nice one of those, too...in the past, I found them to sound very different), there is always a song, where another one manages to 'click in' better and I also read that with a much higher-end they may start to sound a bit more similar.
I could only conclude that I might be more of a "vintage Stax" guy, maybe I just got used to them. If I could keep two, it would be the Lambda and the Omega of course, but with the latter I can prepare to spend an enormous amount of money just to get to that level, where it belongs - the only upside is that the Lambda may also show yet unforeseen levels of music playback. But this might be well into overkill territory to just enjoy music from time to time with issues with space and heat, starts to sound a bit silly...


And just to round out and balance things out a little, someone unfamiliar with stats came over yesterday listening to faster paced, more electronic music, mainly on the KGSSHV, and his favourites were the 009 (apart from crapping on the soundstage) and Lambda Pro, but he was appreciative of the others as well - not just out of respect
So, as always, a matter of personal preference.

Happy listening!

 

Great write-up. I somewhat prefer Spark (20 watts into 8 Ohms) + SRD-6 to the T1S driving my Lambda NBs. With the former setup, sound trace seems fuller, denser, rounder but not blurrier.

If only I knew where to get some mineral wool foams to replace the decayed ones in the 40ish-year-old LNBs.

 

Much love for the Lambda NB! Genuinely surprised they hold up so well versus such strong competition.

I love mine from the Exstata for some things, but am still much more smitten by the Focal Clear right now. I think I just prefer that thicker, warmer, more impactful sound to the precision and air of the Stax.

 

I've been looking into that as well myself, maybe you could try contacting Benson at [ES Lab]?
Since he makes Sigmas from scratch, pretty sure he has something as a replacement for the damping Stax uses.

The Audeze CRBN seems to be another new product where damping is back again, if it is really more like an Orpheus (transducer certainly has a similar shape at least) that would be interesting. Exciting times.

The Omega is a great rock phone, has a lot more impact and volume and the 009 has less volume but even more impact, but of course these won't ever be dynamics or orthos but I don't have any big complaints.
But I feel that the Lambda will be able rock with the right setup, it does not sound bad with it (plus, the Gamma Pro is a perfect cheapskate wingman), most of my complaints put the blame towards the T1W, in this last few days I concluded that amplification is important, it just seems even more complicated than I had anticipated...

Simply put, after setting reference point, which, in my case, was 30 minutes with the HE90, the Lambda seems to be most similar to it, so everything else I have to rate somewhat lower.
Of course, if I had them side-by-side they might be a lot more different, the best I could do is I have my mini-rig at that time (DA11 SRA3S NB) in the hotel room, so I could have an idea of how that sounded in comparison with the exact same material - and that is only the second best pair that I bought 10 years ago - still sounds as it did back then, but the new one is has even better linearity and transparency.
I also enjoy watching movies or YT etc. with them. Voices just sound so clear. Realiser keeps this aspect but gives them a lot more bass, too, based on how the Lambda Pro reacts to the KGSSHV, there is more to come, but yes I would love to have the fuller voicing of the SRA-3S in a more powerful form.


I have given the 009 back to its rightful owner (earcups stunningly well-built btw, if it sounded better, I would just have bought it instead), while also lending this supposedly otherworldly Lambda (not willing to give back the KGSSHV just yet )
Hopefully, within 10 days the 009 will be a partial trade-in for an incoming X9000 (good choice, imho).

Well, I could do a direct side-by-side comparison against the Omega, I'm just not sure anyone would be interested
From what I've gathered so far, general public opinions seem to be roughly equal (2:2)

 

@padam, really looking forward to your impressions of the X9K against Omega and LNB. Among current production ES headphones, the X9K commands most attention for many of us.

 

Great writeup. Thanks for sharing your thoughts @padam

And I love your statement that everything falls down to personal preference eventually. Well, although it per se is quite a general one in this hobby, I saw more of such cases in estat.

I recently came back to Stax after a decade of long break from estats. Since I understand what I'm looking for a lot better than ten years ago, estat games this time around are a lot more entertaining and less frustrating. Admitting my preference could generally disagreeable and trying to come up with my own views were very, very helpful, which I learned from 5.5 years of personal trials and errors in this forum.

To be specific, I found two general uncommon interesting patterns in my Stax love in 2021.

• First, (unlike I assumed) I LOVE analytic flavors as long as they're well-controlled. Prefer it to musicality or life-likeness in many situations. Of course I do have my own cutoffs for them (i.e., things should be 'reasonably' musical and cohesive), but beyond a certain threshold, how components sound articulate, digitalized, yet focused matter to me more significantly.
• Second, I thought Stax needed monstrous amps to drive them right. This still may be true to many users, but not quite as critical to me. I had a loaner Carbon for months last year and had another HV to try out weeks ago. They both were quite good (the former to more extent), but neither was successful to let me ditch my daily driver 353X (my favorite among Stax SS). I still want to try out ifi+Aegir combo some day but that's just because of a curiosity -- rather than a must.

That being said, headphones Stax released after 2018 were all very satisfying to me in presentation. I treasure L700 Mk2 very much, and 009S I heard twice recently (including a home audition yesterday) were impressive enough to debate myself. I prefer them to legacy or vintage ones I tried out. I must be a MLER guy. lol

A full subjective evaluation writeup of L700.2 is pending (Reason: I tried to write an analysis in the beginning but ended up with a love letter in the end -- thus kept discarding) and looking forward to a X9000 audition or loaner opportunity next Spring-ish. And will secretly hunt after well-used, reasonably-priced 009S for myself meanwhile. Oh well.

 

That is a good explanation. There is always a degree of subjectivity involved, but I try to have at least somewhat of a reference point, otherwise I basically have no idea what I should be hearing.
A lot of what the Omega does in parts does sound like live music, shows plenty of signs of greatness, just not quite there as a whole and it is mainly the midrange, it seems that they went with partially sacrificing it to make the stage ginormous in either dimension (I use PICT crossfeed quite often, trading in a bit of excessive width for more depth, another reason why I would not necessarily want to ditch the DA11, or maybe I'm just trying to save money).
If a T2 or something can magically fix that, I'm all in.

What I've noticed with increased power is that the extra clarity gained seems to tackle some of the tonal issues indirectly, e.g. Lambda Pro still sounds a bit u-shaped but I can hear the mids more cleanly, so less of an issue so of course the solution seems to be simple: let's add even more and more (while also fixing some other issues like dynamics).

To add this backstory to my personal (normal) bias, this was in 2012 if I remember right, I went to an audio engineering school while I already started collecting these e-stats and there was a teacher telling me how the HE90/HEV90 was the best headphone system he's ever tested back in 1991 for an extended amount of time to make some recordings, a few years later (I assume 1995) he also liked and used the HE60 (HEV70 amp of course) released later on, at the same time he also tested a few Staxes and he liked the Lambda (I assume the Nova Signature) so I told him to come over one day to test some of mine, I had several but I showed him the 007, Omega and NB Lambda (which I already found to be superior to other Lambdas). He basically explained to me with his own recordings what the first two did wrong next to the Lambda (the 007 was downplayed a lot more than the Omega) that wasn't only a lot more accurate in terms of tone (possibly better than the other he had heard much earlier), but also recreating the original venue of his recording, keeping certain characteristics of microphones. He told me maybe the oval-shaped transducer is a better choice than circular, but later on he also liked the SR-X Mk3 Pro I had maybe a few months after, just not quite as much as the Lambda, not having the treble extension or staging (has a few other tricks up its sleeve though which I care about, he didn't).
Since I am only a mere music listener, not a classical musician and an audio engineer, I valued his opinion, at least for recordings with real instruments involved. So while the NB Lambda may not be the best for classical (mainly due to its bass deficiencies and some colorations another classical player have observed [here] - my copy is much better ), it is still a master of playing it. He didn't say anything negative about the Lavry, so I guess it did what it was supposed to do...

I would like to emphasize that he only tests with his "dry" recordings, others have no value to him, because he can't use those as reference points. And of course, minimally-miked, minimally-processed recordings have their own set of limitations, everyone has their own standards, most types of music is recorded and mixed differently, everyone has their own personal standard. I have read stories about classical conductors using SR009 as their reference, those are multi-channel recordings. Also rated highest on the inexxon site (even slightly better than the S version, or the Omega) with the NB Lambda coming [way down], Gamma Pro [even more] and I found their tone a lot more agreeable than others.
But even on measurements, the NB Lambda seems to look pretty good.

Anyway, in 2016 I was finally able to hear the HE90 by accident, I was mainly supposed to be a HE1 event so it wasn't clear if I could slot into that as well, luckily I could, and of course some of the stuff I carried were excerpts from those recordings. and to my ears, it was inevitable which was the one faithful to them, hearing the other was a bit of a waste of time to be honest, never heard them sounding like that with any headphone, ever. I don't even use those anymore to be disappointed (maybe it's all just in my head now, but still exists).
While the NB Lambda does a really nice job of combining some of the good traits of other Staxes like smoothness, transparency, detail, airiness, somehow the HE90 manages to combine even a lot more. It has extension, it has dynamics, it has realism. [Merv] doesn't exactly seem to hate on them either.

 

What a damn interesting story! I envy you had a long first-hand experience with omega (I assume you own them right?) and got a chance to hear HE90. I had very faint memory on the former more than a decade ago. What's worse I heard it in a meet even when I didn't know how to do subjective evaluation. And to my shame zero chance to hear Orpheus's to dates.

I still have some doubt if I like he90 tho -- as most of favorable comments coming from good (i.e., natural and minimal mic'd) recordings and experienced ears. These days my main focus has changed to what can decompress and over-render stuffs (to make the best use of modern stereo recording via headphones listening).

This is largely consistent with what I noticed from KG's two amps I tested. They did change the perception of tonality while nominal FR unchanged. Maybe my underwhelming impression was because headphones I tested with were of less tonal issues to me (I'm also used to hear past nominal frequency response).

By the way, reading your thoughts, I get eager to hear lambda NB some day. I took lambda signature and nova signature over 507 any day. They were my favorite lambdas until I came across L700.2.

 

Yes, now I only have a faint HE90 memory as well, but besides the different tone, I do remember it was very dynamic compared to the Stax, A key trait that was probably kept in the HE60 as well. Some nice articles still bring back faint memories like [here] or [here] (translator required) and it was also [tested on this forum] as well

Yes, I have owned two other Omegas many years before, this is the third one, since all were the late version, I can't confirm variations (maybe a bit less likely to fail at least). Funnily enough, despite the reputation, the one and only vintage Stax where I had no operational problems, all pairs worked perfectly, some others I had to send back because of channel imbalance. etc.. But each time I see something about the construction, I get very worried, part of the ownership experience I guess...
Yes, can't wait to test the Sig and the Nova again, I should get them just in time for Christmas.

The best way I can summarise the NB:
No range-topping features, amazing bass or dynamic range, highest detail. But it sounds like it's been biased, like...you know... 'normal'? It seems that this is actually quite difficult to achieve, especially if they somehow nail it once, and everything else is simply going to deviate from that. It's just like tasting [Ratatouille], isn't it.

 

After 2 years with the HE90 (vs. 6 with SR-Omega) I'd characterize it to be a rather specialist headphone that shines with acoustic, folk, classical and orchestral pieces. It was capable of very convincing performance out of the BHSE, KGSSHV Carbon and DIY-T2. Regrettably, I never had a HEV90 or Aristaeus during my ownership to understand that synergy.

The SR-Omega is generally more enjoyable as a generalist headphone in more modern music thanks to a more weighty low-end. It's also a bit more reserved in character, sounding somewhat dull and muted (vs. its overall capabilities) on amps below the KGSSHV Carbon/DIY-T2 level. IMHO this included the BHSE where I tended to prefer the HE90s rendering despite the Omega's greater weight.

It's a bit strange because the SR-007 is less sensitive than the Omega, but scaling its amplification (beyond what was minimally viable e.g. KGSS) appeared to give you more of it throughout. The SR-Omega didn't appear to really get going until the KGSSHV Carbon or DIY-T2, where it exposed its epic diffuse headstage and what I consider to be the most satisfying and impactful bass of any electrostatic I'd heard until then.

TBH, I think the headstage and midrange of the HE90 and SR-Omega at their very best are what set them apart. They are not of the same nature as freefield earspeakerls e.g. K1000, SR1a but appeared to offer the most epic realization of "headphone" staging width and depth that I'd ever heard. At their best, neither were particularly precise in terms of imaging (too diffuse) but you didn't really listen to them for that.

I also agree that durability concerns for the SR-Omega might be a little exaggerated, but I think other owners may be less gentle with them (e.g. throwing them around, leaving them in direct sunlight, et al). With just a modicum of caution in handling the earcups I was able to enjoy them without issue for over 6 years, less the headband.

I'm cautiously optimistic about the SR-X9000 as being a modernized SR-Omega as I read more about them, but have awaited detailed impressions out of the KGSSHV Carbon or DIY-T2 as I suspect they might be a little shy to exhibit their potential otherwise.

 

@3X0, thanks for sharing your thoughts. While I agree with you on Omega being somewhat dull or muted in tonality and to a lesser extent, dynamics, I tend to believe that Omega is the most precise sounding headphones I've experienced, which contributes to its sculpture carving-like imaging capability. But you are a long-term Omega owner while I only audited a friend's Omega multiple times, so I ought to have your opinion in mind when listening to the Omega next time.

For me, Lambda NB excels over Omega in vibrant tonality and liveliness while Omega remains on top in terms of precise sound trace and imaging. Hope X9K offers a more realistic opportunity for some of us to get to own a pair of Omega-like headphones.

 

@3X0: Out of curiosity, do you still use any electrostatics regularly? I seem to remember that you parted with your SR-Omega some years ago.

 

I only think of the Omega is being relatively too diffuse vs. traditional TOTL headphones that are known for imaging precision (e.g. Utopia), though I wouldn't necessarily characterize them as such vis-a-vis other Staxen. Regrettably, the only Lambda I'd experienced extensively was the SR-307 though I'd bet that hardly qualifies as one.

Not currently. I sold the DIY-T2 and HE90 about three years ago and had a hard parting with the SR-Omega last year (it sat unused in my closet after the T2 was gone).

I would be very tempted by the thought of the KGSSHV Carbon + SR-X9000, but it certainly wouldn't be a responsible decision at this point.

 

Today I had some more time listen with the KGSSHV.
First track I choose was: Crowded House - Love You 'Til The Day I Die - (title is a bit misleading, this song has a darker vibe to it, definitely stands out compared to the others on the album, that's why I like it).

SR-Lambda Pro
Not bad at all, but less impressive showing this time: prominent, albeit enjoyable treble, sharp transients, but sibilant vocals, a bit 'confused' presentation, too thin and diffused, slightly woolly bass. I wonder if I should reconsider removing of the damping, this is what I read about how the Pro Classic version compares: "slightly wider stage, a tick more bass, improved positioning of the instruments"

SR-Gamma Pro
Much better: more impactful bass, sibilance completely gone, a warmer, more focused, meatier sound. Shame about the dark and slightly soft treble, otherwise quite enjoyable, no big complaints.

SR-Omega
The terminator has arrived. Even though the sound isn't as warm as the Gamma Pro, it is even heavier, more impactful, transmits energy like no other while remaining smooth and very open, sibilance neither hidden, nor emphasized. Amazing detail on the drums, great saxophone, piano and that speed...renders slight changes in the pacing with a much more dramatic ending. Apart from a slightly beautified treble presentation, there is not much wrong with it, sounds amazing.

Then I switched to Eric Clapton - Unplugged. Haven't listened to this album in a long while but one of my old favourites, I expected great things, let's see.

SR-Omega
Well...easy to be bedazzled by the detail, but I remain resilient and say: first impressions aren't that great. Before, I have written about a 'small treble issue at high volumes', the situation is a whole lot different here. With this amp, definitely shows that "live" and "hot" tonality darth nut was talking about and in full scale, present almost through the whole album. You might like that, for me, it's distracting. Couple this to the fast sounding bass which just can't make itself present enough at normal volumes, and the whole presentation is just thinner, brighter and much sharper than I'd like, lacking in body. The soundstage is artificial as well, first time I've tried -2 on the crossfeed setting and it is too much, doesn't fix the problem. I mean, if I accept that this is 'how it supposed to sound' it's fine, outstanding resolution, but I can't help wondering if this is actually listenable on many other Staxes, which have an even harder and thinner sound in comparison. Will be a good test for the midrange etch for sure.

SR-Lambda Pro
Weirdly, the slower bass almost makes it better, more believable and there is no midrange hotness here, the presentation is a lot better, no confusion here. This would sound quite smooth, apart from one tiny detail, and that is the 'usual' piercing treble. On a track like San Francisco Bay Blues, this is especially apparent. A bit of a shame, that one issue can ruin the otherwise impressive experience.

SR-Gamma Pro
Wow. Shockingly good. Everything that was bad on the Omega seems to be fixed here. Sounds warm but not dark at all, I can hear the treble very well, but the sound is way smoother and more inviting, great vocals, guitars, everything. Not quite as fast but much more natural, bass has the breathing room it needs. The soundstage feels much more believable, too. Apart from not being the most detailed (if I switch quickly it does have a slight 'cheapness' to it, but adjusting only takes a few seconds and the detail is more natural) and the bass could be less like an electrostat, but top marks for the Gamma Pro here. I remember this album sounding great on the ATH-ESW10JPN (I guess party thanks to the KGSSHV), this is higher level. I can't remember enjoying music this much for a while to be honest. Unfortunately, after taking them off, I instantly realise that my ears have been pressed on quite a bit. Worth it.

Maybe there some other versions of this album that I ought to try, but to sum it up, it seems to me that on the one hand Omega clearly does some very unique things, particularly the lighting speed, resolution and massive stage it is able to deliver, zips through fast guitar, etc. like no other. However these things don't come for free, and also, they might not always lead to the most natural presentation. Part of the NB Lambda & Gamma Pro appeal is that instead of targeting the extremes, they try to stay in that middle ground, putting out more consistent performances.

 

My time has ended with the KGSSHV, really enjoyed it, plenty of takeaways: it has bass and dynamics far superior to Stax amps. However, the different sound signature makes it more difficult to find a synergistic pairing, and spatiality isn't the best. I like it best coupled to the Gamma Pro, soundstage doesn't play a big part, very nice bass, zero harshness, and the 727 or T1W seem too warm.

The Omega seems to be the most picky, as I don't quite like it with either solid-state amps for different reasons (closed-in with hot upper registers on the KGSSHV, too flat and bland on the modded 727) the T1W is severely limited, yes, soft, but pleasing nevertheless, warmer, smoother, more musical with the most open sound.
Of course, the DAC may also play a significant part in this one, but I would definitely prefer to stay closer to the T1W signature in a more powerful package, I wouldn't want it to be much more linear.

The Lambda Pro seems too lean and bright with the KGSSHV, but unlike the Omega, it matches quite well with the 727, better than the T1W.

Ranking Stax headphones is more difficult than I imagined, each one feels more comfortable in a different configuration - but for me, the NB and Omega will remain as the two top contenders to squeeze the most out of, and I am also curious to see how the X9000 compares and changes shape depending on the setup.