Used headphones – Mjölnir-Audio

Time to split up the special’s page into two so one for headphones and another one for electronics. Here I’ll list my used electrostatic headphones, either they were a part of my personal collection or were a part of some lot I bought and refurbished before listing. Feel free to contact me at spritzer@mjolnir-audio.com if you are interested in any item here. I will reply to every mail so if you haven’t received a reply within 24 hours then feel free to send me another email. Email gets lost all the time or is flagged as spam. All prices in US dollars (USD).

Just a quick note about the used headphones. With all electrostatic phones it is possible that they have developed squealing as debris enters the drivers with age. This is something I actively look for and will put in the description (which most sellers would never do) but I might miss some as it can be so subtle. Most of the time this is a minor issue and only comes into play when nothing is playing or on very quiet passages but it’s something I mention if I come across is. Most of the Stax drivers are glued shut so they can’t be cleaned once this has come up. Also, the headphone stands the phones sit on, are not included.

Here we have the very rare Stax 4070. This is the Mk2 version which helped a lot with the fitment, compared to the Mk1 units which are all but unusable for anybody with a larger head. These are to me, the best closed headphones ever made and nothing short of an engineering marvel. The level of skill and understanding of how electrostatics operate and their particular acoustic properties is just staggering. Current day Stax have nothing on these.

This set is in very good condition, the arc is perfect and just the right slack in the headpad. There are no marks on the plastic shells that I can tell and the only “issue” is that they are missing the serial number sticker. Either it fell off or the arc was replaced at some point and not transfered over. This set is fitted with the original earpads and fitted with the cloth inserts.

They come with the original flight which is also in very good condition

Price: 3250$ plus shipping

The legendary Stax SR-007Mk1 and an early 71*** serial number at that, my favorite version of these. To me the best headphones ever made, they do nothing wrong except being very hard to drive properly. This set is in very nice condition but needed some work. First off the cable had suffered the usual failure so its been replaced with a new black one. These are the only replacement parts available so no way around that. Second the earpads were reaplaced with new ones and finally the elastic in the headpad was fixed. They come with the original flight case and the outer box as well.

Price: 2750$ plus shipping

This is a very lovely Stax SR-007Mk1 of the SZ1 variety. I’m always vary of the SZ1’s as the Stax quality control was a bit lacking back then so some are good… some less so. This was in such nice condition that I had to snap them up and yeah… they are one of the good ones. Equal in sound to the 71*** and 72*** series so one of the best headphones ever made.

They are in such good condition that they must have very little use on them. The arcs are perfect, the headband too with nearly perfect elastic and the earpads are mint. They come with the original flight case and outer box.

Price: 2450$ plus shipping

Here is something stupidly rare, a Stax SR-Lambda from the very first batch, serial number 26. These are a bit different from even just the second batch, the protection grill and thus the driver spacing is different as these use early SR-Sigma drivers. Normally this would head straight for my own personal collection but I just happen to have an ever lower serial number at hand so I figured I’d list these.

When found these, they were a bit neglected but the important parts were all sound, drivers charge up instantly, are fully balanced and the cable is perfect. A lot of cleaning and reconditioning was needed to get them into good shape. The earpads had been replaced in the 2000’s (as those pads are pretty distinct) so no need to change those but the foam was all gone. I’ve been experimenting with replacing that so some foam has been fitted there. It’s not identical to what Stax used but should hold up better overtime. The foam inside the earcups was all gone and some damage to the wool as well. I put it back the way it should be and fitted some of that replacement foam inside the earcups as well. The headpad and arc were just cleaned and reconditioned to maintain the originality.

These do sound great and who doesn’t like a very early version of, arguably, one of the top 5 best headphones Stax ever made. No box with these sadly but they are almost impossible to find at this point.

Price: 850$ plus shipping

This is a love Stax SR-007Mk2.9 in close to mint condition. I’ve performed the port mod on them which further elevates their performance and everything here feels like new so they’ve seen very little use. These are the last good version of the SR-007 as the modern 007S is best avoiced. The flight case is included but no cardboard box with these.

Price: 1750$ plus shipping

Here we have a set of Stax SR-009’s that I’ve been using for some project work. I’ve been pretty vocal in my criticism of the 009 series over the years and I have plans to do something about it with a destroyed set I have here. In the meantime I wanted to try different earpads and how they altered the sound, hence this set here. I’ve concluded my testing so I’m offering it up for sale. I’ve performed some small mods on them and those are the original earpads but I’ve replaced the foam inside them with my own memory foam. This makes them a bit bigger (as can probably be seen in the pictures) but improves the bass performance which these have always lacked. Also improves comfort and they will last much longer than the stock foam.

They are not in perfect condition with some small nicks in the silver housings, a small tear in the base of one earpad (the only part that is not genuine leather but it has no effect on performance) and I replaced the headband pad on them with a new one. There is no original box either with these but they will be well packaged before shipping.

Price: 1500$ plus shipping

Here is something rare, a fully working Stax SR-1. It is one of the latter versions of the SR-1 so fully compatible with the Stax normal bias standard. I’d place them from 1964 or so and they are still 100% original. The drivers had wax seals at that time and they are all still there. They charge up instantly and are perfectly balanced This is the first ever Stax set and quite rare at this point.

Price: 2000$ plus shipping

Here is a very good condition Stax SR-007Mk2.9 set which I’ve performed the port mod on. Everything here feels like new so they’ve seen very little use. These are the modern version of the 007Mk1 and a bit better than the current Mk2.95 that Stax sell plus I’ve performed the port mod which allows them to reach their full potential. The flight case is included.

Price: 1850$ plus shipping

This is a really rather nice set of Stax SR-307’s that come with the original box. In terms of sound, these are very similar to the SR-407 (same drivers are used) and a more neutral sound compared to the older 303’s. Excellent bass for a Lambda series set and overall very enjoyable headphones.

Price: 375$ plus shipping

This is a like new Stax SR-007Mk2.9 set and everything here feels like new so they have clearly seen little use. I’ve performed the port mod on them, which allows them to reach their full potential by sealing the baffle as they should have been from the factory. I came across the flight case and box for these so they have been reunited.

Price: 1850$ plus shipping

Koss ESP/95X that I’ve fitted with new sheepskin leather earpads and installed a Stax Wide PC-OCC cable to them. I’ve also modfied the stock damping to make them sound even better. Great sounding headphones when they are driven by proper amps and have the right earpads on them. They are in excellent condition

Price: 650$ plus shipping

The legendary Beyerdynamic ET-1000 headphones, the best they have ever made in my opinion. These are pretty rare now in good working condition and this set is excellent, no imbalance issues or anything like that. They come with an adapter to use these on normal bias Stax amps which is a large update for them

Price: 800$ plus shipping

Stax SR-Alpha Pro which comes from my personal collection, I’ve been organizing it and I don’t need multiples of these. This is the Japan only version of the SR-Gamma Pro using the same drivers as the SR-X Mk3 Pro. Great sounding headphones and I’ve made them better by fitting the perfect sheepskin earpads for them and a sheepskin headpad.

The only issue is that one the clips in one of the headband sliders has cracked but it still works perfectly. Other than that they are in great condition and sound excellent.

600$ plus shipping

Here we have an all original Stax SR-Lambda Pro set. This was the first Stax Pro bias set and very popular at the time. This paired with a Stax SRM-Monitor is an excellent combination or even just with the Stax SRM-1 Mk2. Warm, full sound that is means you can listen for hours on end. They are in nice condition with the usual stuff for a set this old. The foam inside the earpads is all gone and the foam inside the earcups has started to break down so I just left it in place. It is impossible to replace with the fragile mineral wool over it.

Price: 520$ plus shipping

Stax SR-Lambda normal bias set, pretty early production at the #4600 range and in very nice condition. The SR-Lambda is one of the best headphones Stax ever made, they are a bit rolled off at the top end but the midrange and soundstage is one of the best there is. Warm sounding and very pleasant.

This set is in excellent condition for a close to 50 year old set, the foam has started to break down inside the earcups but it has no effect on performance so I just left it alone. The earpads are good condition too but the foam there is long gone as is usual. These do come with the original box which is rather rare.

Price: 675$ plus shipping

Here is the holy grail of the Lambdas, a set of the original SR-Lambda normal bias and an early one at that. These are getting thin on the ground and the prices match that demand as it is one of the best sounding Stax sets ever made. Very balanced sound signature which does nothing wrong really. Also very comfortable for long listening sessions. The left channel takes about a minute to charge up compared to the right hand side but the difference when it is happening is quite mild. After that they are fully balanced and sound lovely.

This set arrived in quite good condition and looks fully original. The earpads have seen better days but I treated them and put in the close inserts as the foam is long gone. I made some small repairs to the headband so now they function as they should. Overall a nice set of these very rare sets. They come with the Styrofoam box but not the outer paper sleeve.

Price: 695$ plus shipping

Here is a lovely set of the legendary normal bias Stax SR-Lambda. The original Lambda and an attempt to take the SR-Sigma and make something sensible out of it. It really is in a class of its own in terms of sound, very balanced with great presence while trading a bit of extension at the extremes.

This set is in lovely condition given its age and looks to be fully original. I did open up the earcups to check out the drivers, clean out the crumbling foam and remove the protection silistors as they don’t age well. The mineral wool covering the back of the drivers isn’t perfect but it does its job. This one comes with the original styrofoam part of the box but not the outer cardboard part.

Price: 650$ plus shipping

The legendary Beyerdynamic ET1000, on of the best headphones of this generation. Great sounding units when properly driven and surprisingly comfortable. These require a bias voltage of 180V but they work just fine off Stax normal bias outputs. An adapter to do just that is included with the headphones.

They are in good condition, save one mark at the top end of the headband cover. The earpads are nice and soft and they charge up instantly and sound perfectly balanced.

Price: 700$ plus shipping

This is a nice set of SR-202’s that are all original except the foam inside the earpads had disintegrated with age. To remedy that I fitted my own inserts that I’ve been tinkering with. The budget Stax sets are often overlooked but I value them highly, they have a slightly more raw sound compared to the more senior models, not quite as refined but that works with a huge range of music. This set is in lovely condition and comes with the stock box.

Price: 335$ plus shipping

This is a Stax SR-202 and it is in fine condition, all the foam inside the housings is intact but the foam over the driver face had crumbled away. I cleared off the rest of it and fitted my own dust covers there for a nicer look. The 202’s sound closer to the older Stax Lambda Pro’s in many ways and I do enjoy them quite a bit. Very fast and honest sounding.

Price: 265$ plus shipping

A Stax SR-507, when Stax decided to take the SR-009 headband and cable plus the 404LTD leather earpads, and cram it all on a Lambda shell. They sound pretty different from the 407’s, brighter so a bit more like the old Lambda Signature in some ways. Still an improvement over the modern L700’s to my ears. These are pretty sought after now and increasing in price as not many were sold back in the day

This set is in lovely condition and no original box for these unfortunately.

Price: 700$ plus shipping

Here is a very early Stax SR-404 in excellent condition. It has the same drivers as were used in the 404LE later on and it is all original except the foam inside the earpads had crumbled away. I fitted my own replacement cloth there as can be seen on the second picture.

Price: 425$ plus shipping

Here we have the original Stax SR-Lambda in very nice condition. I cleaned out the crumbling foam in the earcups and fitted my own covers over the drivers as the foam had fallen away a long time ago. Other than that they are just lovely, cable is nice and supple, headpad close to perfect and so is the arc.

One of the best headphones ever made, similar to the Quad ESL57 speakers in trading a something off the extremes for one of the best midrange ever. These come up to song instantly and they come with the Styrofoam part of the box but not the outer paper shell.

Price: 590$ plus shipping

Here is a Stax SR-007Mk2, Mk2.9 version. These are in perfect condition and I also performed the port mod so they sound like they should. The Mk2’s and A models are identical, it was just the color difference that set them apart until Stax made a limited run of black 007A models. In terms of sound, with the port mod, these sound very similar to a late production Mk1 unit. It comes with both the flight case and the outer box.

Price: 1800$ plus shipping

Here is a mint set of SR-L300’s for sale. I got these by mistake really as I wanted to add the L300 to my collection and accidentally bought two of them. 🙂 These come with the original box and they look good as new.

Price: 350$ plus shipping

This is a set of SR-Lambda Pro’s which arrived in a rather sorry state. The sound was excellent though, balanced and extended so they had to be saved. Earpads and the entire arc were trash so the whole thing was cleaned on the outside (it’s not a good idea to disturb the earcups on these as it changes how they should sound), the cable cleaned and treated, new earpads fitted and a used arc from a SR-202 fitted. Very nice sounding set of headphones which can now go on to play for another 40 years or so.

Price: 350$ plus shipping

Here is a stock Stax SR-L300 in mint condition. These have now been superseded by the SR-X1 but L300’s are a much more comfortable set of headphones and have a much larger soundstage. They come with the box as pictured.

Price: 380$ plus shipping

A Stax SR-407, the last of the old school Lambda models. It adds a bit more bite to the sound compared to the SR-404 it supersedes with a bit more bass and usable output. This set is in very nice condition and all original.

Price: 535$ plus shipping

A set of SR-303’s in nice condition and all original. This is the later production version with silver protection screens for the drivers. Stock earpads and headpad in place though the foam inside the earpads has disintegrated as they all do at this point. Very nice set of headphones that would have been a shame to break up to upgrade some Sigma’s.

Price: 375$ plus shipping

Here is a rather nice set of Stax SR-Lambda Professional’s, all original and even the foam inside the earcups is mostly intact. These are warmer sounding than the normal Stax Lambda units and pair really well with the SRM-1 Mk2 amps.

Price: 500$ plus shipping

This is a mint set of SR-L300’s but I’ve been modifying these to try and clean up the sound a bit. Small mods but yeah, these are an improvement over the stock units and something I’m going to look into further. They come with the original box.

Price: 325$ plus shipping

Price: 550$ plus shipping

Stax SR-Lambda Signature, the flagship Lambda from 1987 which was the first radical change to the Lambda series. All the damping removed and drivers fitted with 1um diaphragms. Lovely sounding headphones that really benefit from powerful amps. Open sounding and very clear. This set is all original which means all the foam has crumbled away and the left overs removed. The stock earpads are nice and supple and the headpad is in lovely condition. No original box with these.

Price: 700$ plus shipping

The very nice Stax SR-507, top of the line model from the *07 range and a rather rare unit at that. This set is in great condition, some slight marks here and there but earpads are close to perfect and they sound great. No original box with these.

Price: 650$ plus shipping

This is a late production SR-404, all original with the box as well. The foam inside the earpads has deteriorated so I just cleaned it all out as it does nothing anyway. Not sure what else can be said about the 404’s, they were very misunderstood back in the day but have gained a solid classic status at this point. A good set with a powerful amp can show what the Lambda was capable off well into the 2000’s.

Price: 550$ plus shipping

Here is something very, very rare. In my 20 years of collecting Stax, I’ve only ever seen five of these come up for sale and I’ve bought 4 of them. What we have here is a Stax SR-Lambda Pro with no Stax badges at all, marked Head-Acoustics instead. In fact the only Stax logo at all was on the box as these shipped in a standard Stax Lambda box, completely unmarked except for the unique “HA” serial number. Just the Stax embossed into the Styrofoam. I have no idea how many of these were made, this is the highest serial number of my collection, HA 543 so at least that many.

As can be seen, these don’t have a regular Stax plug but a 5 pin Lemo unit instead. They will come with a custom adapter though so you can use them on any standard Stax amps. In terms of sound, this is a standard Lambda Pro, but it just looks so weird without the Stax markings. No box with these.

Price: 600$ plus shipping

This is a clean and tidy set of SR-303’s. The foam inside the earcups and covering the drivers had degraded so I cleaned it out but otherwise they look great and sound even better. Comes with the original box as well

Price: 350$ plus shipping

Like new Stax SR-L500Mk1 fitted with the aftermarket sheepskin earpads. These are lovely headphones and have a fuller sound than the L700’s. These come with the original box and all the documentation from Stax as well.

Price: 600$ plus shipping

A completely stock SR-L300 in very nice condition. I’ve always been meaning to do some projects with these so I keep buying them but alas, nothing has come of it yet. This set is close to new in condition and comes with the original box as well.

Price: 295$ plus shipping

This is a very early Stax SR-202 in nice condition. Being the entry level Stax, they don’t always lead an easy life but this one is just lovely and looks like new. These come from the age where a layer of foam covered the drivers and that has naturally broken down but the earpads are in lovely shape though. Very good sound from these, maybe not as refined as the 303/404’s very close in sound.

Price: 285$ plus shipping

Lambda Nova Basic, the successor of the Lambda Spirit as the entry level Stax set of the day. They carried over a similar driver structure but fitted with the then new headband design. Similar to the other Nova series the sound is warmer and more forgiving than the older Lambdas. This set is in lovely condition, the foam over the driver face is long gone but otherwise they look great.

Price: 330$ plus shipping

Updated 27.03.2026