Electrostatic earspeakers, original lambda design.

Stax SR-Lambda (Λ)

  • Electrostatic earspeakers, original lambda design.

Recent Reviews

  1. DJ The Rocket
    True Audio Giant
    Written by DJ The Rocket
    Published Jul 13, 2017
    Pros - Among the best SQ available on Earth, comfort
    Cons - None.
    Note: this review is for a Stax Lambda Pro. I'm not certain each review is for the same model here :/

    This headphone (along with a Stax SRM-727a amp) is the finest audio experience of my life. If you're used to dynamic drivers, it'll be a shock the first time you hear what music is supposed to sound like. There is ZERO muddiness anywhere in the spectrum. Every frequency is reproduced cleanly and separately from the others. Voices and instruments sound so realistic, in unfamiliar music I'll often think someone is in the room with me, before realizing it's just the recording. Most concert venues don't sound half as clear.

    If the sound balance right out of the box isn't what you're looking for, not to worry, they respond perfectly to an EQ, and will take on whatever sound signature you desire, at whatever volume (these sound just as good quiet or ear-bleedingly loud). Personally I like boosting 200hz ane below by 4db or so.

    Most everyone talks about the mids or the highs, which are indeed world-class, and sharper and crisper even than any planar magnetic driver can manage. But for me (an EDM & hip-hop listener) the bass was the real revelation. Where even the best dynamic speakers produce a deep indistinct boominess, these can articulate the bass exactly, and you can suddenly tell the difference between a 20hz and a 22hz tone.

    Even the sennheiser HD800 sounds slow and artificial sounding compared to the Stax. I haven't heard other electrostatic headphone systems (be it other Stax models, the Koss ESP950, or the absurd $10,000 Sennheiser HE50), but no dynamic, no planar magnetic driver can come close to doing what this Stax electrostat can.

    Obviously your source matters, but even streaming soundcloud from the headphone jack on my phone sounds phenomenal through these. Using a hi-fi DAC such as the Mojo or GOV2+ is even better of course, but the gap between my phone (an LG V10 with a relatively great DAC to begin with) and those hi-fi dacs isn't nearly as great as the gap sounds when using regular headphones. I prefer a DAC that gives a lot of body to the music, such as the Hifiman HM601. Using a bright DAC might not be the best pairing.

    While the astounding sound quality is the most important thing, I'd like to say a few words about build quality and comfort. The build quality is nothing special, they seem to be made of a cheap plastic, but I've learned that a cheap feel does not mean it's actually flimsy, but I baby mine anyway just in case. As these are the least portable headphone type on the market, that's not much of an issue. They will never leave the room where their amp is set up.

    Comfort-wise, they are exceptionally comfortable. They weigh very little, and exert almost no clamping force on your head, but somehow they never slip off while you're wearing them either. The main issue related to comfort is the fact that they rely on static electricity to produce sound, and bumping your hand to the outside of the case can cause a quick grounding on that side, and you will only hear through the opposite side for a minute while it builds up a sufficient charge again. It's a minor issue that's inherent to the technology.

    IN CONCLUSION, these are the best headphones I have ever heard, they put most $1,500 pairs to shame (ahem HD800 ahem), and if you know how to EQ for yourself, there is no reason you wouldn't be blown away too.
  2. padam
    Musicality at its absolute best
    Written by padam
    Published Nov 19, 2013
    Pros - Midrange, midrange, ... oh, and did I say ... midrange? Sounds great even on a basic setup, but really transforms on a good one.
    Cons - Still a bit bright, mediocre bass and imaging, not that easy to get in decent shape
    So, you were researching this headphone...and wondered: "Should I go for it?"
    Do you like acoustic, vocal or classical music?
    Well, if you do, firstly, I would say you should probably pull the trigger before someone else does. And then you may continue reading this - in a more relaxed matter :)
    You should pay attention the condition though, some of the pairs I've seen here had a rough life, and might not be a faithful representative of what these are capable of.
    Killing a Stax is not easy, but it is possible unfortunately. Mine was't in a nice shape either. But a standard head- and earpad replacement really gave it a new lease of life. Being an early pair, you just wouldn't believe that it is now probably more than 30 years old, let alone hear how it can just simply crush almost any modern headphones with the types of music I mentioned.
    I mean it, seriously. Calling this a great value headphone is somewhat of an understatement.
    For my taste it is one of the best I've heard. Why? Making an instrument sound like an instrument on playback can't be that difficult, right?
    But the truth is, the midrange is really hard to get right. And I am happy to report that this headphone pulls this one off.
    Guitars, vocals, etc. are just magical on this thing, but not because they are immerged in some virtual mass of sound trickery, it is simply because they are presented in a natural way.
    The detail is there, but not in your face. The speed is very good, but does not go to extremes, very nice transients thanks to the damping. The soundstage is airy, but does not get too diffused, so you can always keep an eye - I mean two ears - on what's going on.
    And here is the best thing: making an SR Lambda sounding bad is no easy task (if you like it's basic character, that is). Even when paired with a cheap (but well-thought-out) system using an adapter, it still sings beautifully.
    But give it the source it deserves and drive it with a top tier amp, and everything becomes bigger and clearer, even the bass gains some snap as well.
    So, what's not to like?
    Somewhat bright sounding, so some people may find it glaring and a bit tiresome after a while. The imaging isn't nearly as good as the best out there (although more than holds its own in its price range).
    Also, the damping does lower the bass output and quality somewhat. It does extend lower than you'd expect, but it is not for bass-heads. So don't put a bright DAC before it.
    And really, its main positive far outweigh these on its own.
    Not much to say on the comfort front. With new pads, I am finding them to be very comfortable. The older style headband allows a bit better angle adjustment than the newer ones.
    Maybe I should deduct a little on the design because of it looks and its plastic construction. But, since I am not sure it would sound quite the same with this and that changed, I won't.
    All in all, I am not quite sure of the reason why moving to the Pro standard, improving the technicalities also made a backwards step in naturalness - maybe the reason why it was still being produced until finally coming to a halt in 1994.
    I don't mean at all that the rest of that Lambdas are bad, far from it - that said, I am not a huge fan of the current ones...
    And imho neither of the others really seem to have that...something that this one does. And sometimes...something...means...everything. Or not?
    Anyway, it's time to end, thanks for reading :)
    1. View previous replies...
    2. padam
      If driven properly, the Sigma NB is actually quite good for rock, because of its boosted mid-bass.
      padam, Nov 21, 2013
    3. Jonathan66100
      I drive with a SRM1 :$ but i don't love much the rock in any way :p
      Jonathan66100, Nov 21, 2013
    4. thebrunx
      Just Got this with SRM1, GLORY! mine are not bright I think this depends on source, I use battery to power my DAC which makes the sound more clear and softer, its more clear than a live concert (rock), hd600's just can't compete. where do you go from here?
      thebrunx, May 28, 2016
  3. juantendo8
    The True Giant Killer: A Value Comparison
    Written by juantendo8
    Published Nov 29, 2012
    Pros - Astounding Sound Quality, Comfortable, Can be had for cheap, Durable
    Cons - Condition varies with such an old headphone, Not portable, Design won't win any fashion awards
    Getting Your Stuff
    This headphone is the true giant killer if it is obtained with an SRD-6/7 transformer box. Keep in mind that you will need at least 10 watts of power (>15 recommended) from a speaker amp to adequately power these things. Vintage amps are wonderful. If you don't have one, consider getting a TA2021 class-T amplifier which can be had for as little as $40 on Ebay. Amazingly, that combo sounds glorious and doesn't leave one wanting. If you can get the complete setup for under or around $400, you are partaking in one of greatest values that exists in the audio world. It is also a stellar first visit to the world of electrostatic technology.
    The Sound
    This review is mostly a value proposition, but it wouldn't be appropriate to leave without at least one subjective account of these headphones with some objective data of course.
    They sound magnificent. If you are used to dynamics, these will sound more linear, open, airy, and non-fatiguing than probably anything you have heard. They are not bright headphones, being the least bright out of all Lambdas. They are not dark in the slightest. They are extremely neutral and are fantastic all-rounders that sound great from rock to pop to classical. I would have to say that these sound particularly gorgeous with good classical recordings.
    They have a bit of very low bass roll-off, but I hardly ever notice it or find it bothersome. If you listen to dubstep 24-7, these may not be for you, but I don't think you would be looking for Stax anyway. They have a great mid-bass punch that is fun, but mild enough to not muck up the sound. They have a gentle emphasis on the mids that I find beautiful and tends to bring out voices very nicely.
    The air on these is amazing. They are very full sounding headphones that are also the last headphones that I would call "congested". I thought the K501 was the champion of an airy sound stage until I heard these. This amount of air and effortlessness can only be created on electrostats.
    Value VS
    There are of course other options to be had if you are looking into budget electrostatics. I picked the three that I believe are the most common alternatives. I will try to briefly discuss what I find better and what I find worse about them vs the original SR-Lambda SB (standard bias).
    Stax SR-Lambda Professional: This would be the most common alternative. After all, it is the direct successor to the original Lambda. It would follow that it would do some things better.
    The Good: It can often be found for the same price or even slightly cheaper than the SB. Availability is usually quite a bit higher. The bass extension is a little better. The professional bias amp or transformer box that is needed with these can be used with any later Stax headphones that you may decide to purchase.
    The Bad: The frequency response is a bit more wonky and less linear. You lose that small mid emphasis that is very appealing. The headphone is brighter with an upward tilt that is not existent in the SB version.
    Overall: This is a great headphone that can be an even better value than the version that I am reviewing. The improvement in bass extension aside, I found the frequency response to be mostly inferior while adding a brightness that was not previously present. If you intend to keep these for a very long time, I think that waiting for a good value on an SB version would be preferred overall.
    Koss ESP-950: This is a more expensive alternative that may be more appealing depending on your musical tastes.
    The Good: This headphone is very linear, although not as much as the Lambda SB. It is a bit more laid back and less bright than any Lambdas. There is an emphasis on the lower mids that is more intense than the one on the SB and creates a very full and seductive tone on voices. Transparency is probably a little higher than on the vintage Lambdas, likely because of a much newer design. AMP IS INCLUDED, NO SPENDING MONEY ON AMPLIFICATION!!! Lifetime warranty, no questions asked. Parts replacements are cheap.
    The Bad: It is hard to find a good deal. They will sell for $1000 normally, but they can be gotten for $500-$600 on amazon if you are diligent in checking and commit quickly. Not everyone wants to deal with that. Drivers have been known to squeak and drivers have malfunctioned and needed to be sent in for replacement. Amplification upgrades can be difficult.
    Overall: It is a phenomenal headphone that is definitely worth it for $500-$600. The sound signature is more full and less airy than any Stax, which may be enough for consideration for some people. It is certainly not the most neutral electrostat, but it is one of the least fatiguing and is great for long listening sessions. The build quality is not quite up to the Stax level, but that lifetime warranty should keep your worries away.
    Stax SR-207: This is the brand new "budget" Lambda, if the thought of buying used is distasteful to you. It can be a great value. Buying with a new amp will push these to a more expensive price range, so these are not really that good of a value compared to others. They are around $400 new for just the headphones.
    The Good: Basically, they are more technically proficient than the older Lambdas. They are a little more detailed and have better extension. This is because of the newer technology. They also can be gotten brand new. Buying used would save you even more money, though it is difficult to find these used.
    The Bad: They are a bit bright. They follow the ongoing trend of Lambdas having an upward tilt in their sound signature, and being susceptible to excessive brightness. The tuning is certainly not as neutral or natural sounding as the Lambda SB. Can be quite expensive with amp.
    Overall: I cannot honestly recommend these from a value perspective. If you want a new headphone, I would wait for a deal on a Koss ESP-950 which is a better headphone IMHO. Bought as a system with amp, the cost is around $800. Paired with an SRD-7 Pro, the Koss ESP-950 competes with and beats out this system.
    My Ratings
    Here I will attempt to explain my reasoning behind the star ratings that I have given the SR-Lambda SB with SRD6/7 combo.
    Value: I obtained my combo for $350. No dynamic headphone except perhaps the HD800 can hope to challenge the sound quality and that is more than 4x the cost. Enough said.
    Audio Quality: The only real weakness is a slightly lacking bass extension. The tuning however, is near perfect. IMO, this is one of the top two best tuned Lambdas made, and leaves nothing to be desired. Neutrality, musicality, transparency, openness and air. No brightness. This is a sound that you can be content with for a lifetime.
    Design: The build is very minimalist and sturdy. It is about 30 years old, and looks and behaves good as new. These older Lambdas supposedly are built even better than the new ones. I will ding it a star for just looking odd. You would not go out with these and your friends may make fun of you, but the less superficial will know that the joke is truly on them when they walk outside with their rapper phones.
    Comfort: Quite frankly, these are some of the most comfortable headphones that I have worn. They have very low clamping pressure, but the cloth headband does a stellar job of stabilizing these on my head. Since these are so open, my ears are free to breathe easily. I dinged a half-star because the pleather may cause some skin to sweat if these are worn on a hot summer day. Not a problem to me, but others may differ.
    Overall: I find it fitting to end this value review on the overall rating. I heavily contemplated giving this a full five stars. In a perfect world, I would have without hesitation. My half-star ding has nothing to do with the presence or lack of merit within this headphone. Rather, it is the fact that you will be investing on a 30-year old product. No matter how well built that product is, a lot can happen in 30 years. There will always be a little risk when buying a vintage product such as this.
    As such, make sure that you ask plenty of questions about the product before you commit to bidding on it. Make sure that there is no room for the seller to short-sell you. Once you bid and win, you are obligated to pay. With enough questions, you make sure that you don't bid on a faulty or under-performing product. Even better if you can buy from someone you know or an enthusiast community such as this. For some reason, Stax vintage headphones seem to be somewhat under the radar on this site (hopefully will change), and the risk is usually much smaller than buying from other bidding sites.
    In conclusion, this is a phenomenal value headphone that may finally cure that itch to continue spending on upgrades. At least until you decide to go to the top of the electrostatic world.
    1. View previous replies...
    2. paaj
      The Staxes sure are sexy... ahem... but the sound!
      I'd hunt for one of these, actuelly I did hit something similar this week :)
      paaj, Nov 30, 2012
    3. juantendo8
      Thanks for the comments, guys. I just felt that I owed it to myself and others to get this semi-review off my chest for those who may be thinking of trying some 'stats.
      @Mshenay, I owned some DT880 600s and I think that they are one of the better and least flawed headphones that Beyer has made. That said, the Lambdas are a definite step up (less bright, no recessed midrange, more detailed and transparent, even more air), even if more expensive. If money is a top concern, the Beyers are great.
      juantendo8, Nov 30, 2012
    4. wdiabc
      I was lucky enough to find one pair as well. It sounds exceptional, I had sr001( the in ear little stax) before and Lambda SB version is a true step further. The clarity and musically of this phone beat many other headphones I have heard.
      In my opinion, Dynamics cannot really compare with staxs, Orthos may have a chance because of its smooth sound and liquid mids. But in the treble range, nothing comes close to staxs to be honest.
      wdiabc, Feb 20, 2013


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