ES Lab ES-1 alpha (ES-1a) Electrostatic Headphones

General Information


Capacitance:105pf w/ cable
Sensitivity:95dB / 100V r.m.s. 1 kHz
Weight:520g w/o cable

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Headphoneus Supremus
ESLab ES1a - Full Review
Pros: Balanced tuning
Cons: Bit Heavy
Loose clamp

Hi Guys,

Today we are talking about a very interesting headphone from Hong Kong, made by the company ES-Lab. ES Lab started out repairing old Stax headphones, and doing DIY work, eventually leading to the release of their ES1a headphone, their take on the Stax Sigma, and most recently their recreation of Sony’s legendary R10. The ES1a is styled after the original Stax Omega from the 1990s, but all in black, with gold screws. Although the looks are very similar, the sound between the original Omega and the ES1a is supposedly somewhat different, although I have never heard an original Omega to do a direct comparison. The ES1a retails for right around $1750USD which for the performance it provides, is honestly quite compelling in todays headphone market, especially in term of electrostatic headphones.

The vast majority of this review was done with the HeadAmp BHSE, a KGSSHV Carbon, and an iFi Pro iDSD DAC as supporting gear.


In terms of level, the bass of the ES1a in its stock tuning is not enough for my personal preferences. I think this may partly be due to the very loose clamp force the headband provides. I do have quite a large head, and even I found it to be a very loose fitting headphone. When I very lightly provided a more secure seal, the bass level did rise slightly, and seemed to also be a bit punchier. If you are open to EQ’ing up the bass via a simple low shelf, then that also solves the problem easily. There is about the same amount of bass as a stock SR009 I find, and certainly a bit less than the SR007mk2. With that being said, after a small EQ boost, the bass is entirely satisfying, and has a somewhat rounded off leading edge. There is slightly more impact than the 009 and about the same amount as the 007. Overall, I think people’s perception of the bass may differ depending on the clamp level they experience from the headphones, and the seal they are able to get with their head shape and the ear pads , but the overall bass quality is actually very good and can be tweaked via EQ to the users preference. Once thing to note is that it helps to have a powerful amplifier, as these headphones are quite hard to drive, especially if you take negative gain compensation on the EQ if you are boosting the low end.

The mids of the ES1a make them a less thick and warm sounding headphone than the SR007mk2, yet less cold and thin than the SR009. They really do split the difference between the two quite nicely. There is a slight amount of warmth and “sweetness” to the mids that I really enjoyed. Around about 1khz there is a bit of a bump I think, and this seems to be an electrostatic thing, as a lot of examples I’ve tried have this bump. Honestly, I could have thoroughly enjoyed these without any tweaking via EQ, but I wouldn’t be surprised if some people preferred a little dip via EQ at around about 1khz. I never found the ES1a to sound somewhat nasal and honky due to the 1khz range where on some other headphones that certainly can happen. Apart from that, there really isn’t much I found about the midrange of the ES1a to be offensive at all. I really liked how these headphones worked with all sorts of music styles and were never overly shouty or harsh in the upper mids.

The treble performance of the ES1a is where it excelled for me personally. There is a bit more energy in the highs than the SR007mk2 but less than the SR009, again splitting the difference between the two very well. I didn’t find the treble at all tizzy or sharp, bright or harsh. Yet at the same time it never sounded dull or as if it was smoothing over details and going towards being a darker tuning. Overall, the treble response of the ES1a is probably the best aspect of its overall tuning and is incredibly pleasing and addictive. In a way, it reminds me of the treble of the Hifiman Susvara. It’s not as finely detailed as the Susvara, but in in terms of its overall character and tuning, there were similarities to my ears.


In terms of technical performance, the ES1a is quite impressive, especially in terms of their price/performance ratio. Their overall detail level seemed to be quite similar to the 007mk2 from Stax, but the overall sound image was much larger than both the SR007mk2 and the SR009. The soundstage was wider, taller, and larger front to back than both of the Stax offerings. I suppose this may have to do with their pad shape and tuning. Microdetail was also quite well done for an electrostatic headphone in this price range. I did find that they were again similar to the SR007mk2 in terms of their dynamic performance, both micro and macro. Nothing groundbreaking, but again, very good for the price.

The ES1a is about on par with the SR007mk2 in terms of how hard they are to drive, meaning they seem to love power, and will do best with a good powerful electrostatic amp behind them.


In terms of build quality, the ES1a seems entirely acceptable and actually feels more substantial than the SR007mk2 The construction materials are a mixture of metal and plastic, and although they do weigh quite a bit, they never felt like a burden to wear (as some Audezes and similar can feel over time.) I would personally like slightly more clamp force, simply to make the ES1a feel a bit more secure and snug on the head, and I also think it might help their low end performance slightly. The cable is very similar to the ribbon cable you get with Stax headphones, and seems well built, and does the job nicely. In terms of aesthetics, I think they look awesome. They take the shape and design language of the original Stax Omega and update with a sleek all black look, with slight gold accents from the screws. It works for me, and I think they are one of the better looking headphones I have come across.

Photo taken from ES-Lab website

Overall, the ES1a is a great pair of headphones, especially if you tend to favour electrostatic headphones and what they do well. Although the low end in its stock tuning isn’t really anything groundbreaking, the mid and treble tuning are very well done, and the detail and technical performance is very good for their asking price. If you don’t mind boosting the low end a little with a bit of EQ, then I could see these being great all rounders. If someone were looking into buying a Stax headphone at SR007/009 type pricing, but can’t figure out which they would prefer, or just want a better all rounder whilst also saving some money, I would seriously recommend giving the ES1a a try. They seem to split the difference between the two former flagships from Stax, and also look better (in my opinion) whilst doing so.
Great review and aligns with my experience, particularly the way they split the difference between the 007 and 009. I like to think of them as the unofficial 008.
Excellent review!
I worked with the builder to create a slightly more substantial headband. It is not a huge shift but clam is slightly improved. If it really bugs you, you might reach out and see if he can fabricate a copy of the version I have.


excellent performance
Pros: comfortable
ear cups - sturdy construction
Cons: lacks bass of 007s (for bassheads)
plastic headband (durability)
Quick introduction about myself. Used to play the guitar (primarily electric) and a little bit of piano starting in middle school through high school. Back then I mostly listened to rock, rap a little bit of R&B and metal. (to date myself i grew up watching MTV; listening to KROQ and power106 if your’re from LA) Wasn’t until college that I started to expand my music interests. After going to many festivals like Bonnaroo, High Sierra, Outside lands, Gathering of the Vibes, Lockn etc got many chances to explore a lot of different types of music that i now listen to today: jazz, world music, classical, acid jazz, blues, rock and a lot more electronic (house, trance, trap) as well as phish, string cheese and the dead.

I’ve always had headphones in my ears whenever traveling and when possible at work. A few years ago i discovered the 6xx and 7xx drop headphones and thought that was my end game. With COVID and spending more time at home with a change in my living circumstances (cant blast my speakers as often) I decided to see what was out there with headphones this past year.

While trying out some of the top tier headphones (eg DD focal clears, planar (aryas/lcdx, and electrostatic l500mk2,007mk2) and IEMs(mest mk2, monarch mk2, sony ier m9 etc); while they all sound great… the biggest realization was that I discovered i had been missing out with stax all my life. I’d never heard of them before and dont even remember how i came across them the first time…


the first time I listened to a live phish recording it sounded like I was actually at the concert (course the key is : you got to close your eyes and do this in a dark room).

Anyways having had a chance to experience the L500mk2 as well as the SR 007mk2 was always curious what is 009‘s were but don’t ever see myself paying that much just for a set of headphones. It was already a big step going over the $1k mark as i’m sure many of you have experienced, I never thought I’d do it but had to find out for myself.. And yes, its just diminishing returns beyond a certain point. Plus, I’d rather just use my money for live music and experience it in person.

So here we are with the es-1a. what my research has indicated was that this is in between 007 and a 009 as far as a sound since i knew i’d never buy the 009s I thought why not.

I was a bit skeptical and unsure what to expect from all the glowing reviews but have to admit - overall i think this set is tuned perfectly for all types of music and i know you might think… usually jack of all trades aren’t actually good at anything, but i’ll leave that up for your to decide..

Fast, deep, dynamic, clean.. Listening to John Summits live set from Ultra 2022 will have you bobbing your head to every single bass note. It’s not as textured as the 007s (which have a palpable oomph) but its there. Same with Above and Beyond “Screwdriver” which has a nice bassy acid mid-section

listening to Lizst piano sonatas (Annees de pelerinage S 160:no6 Valleed’obermann) the piano notes are crystal clear and never muddied or distorted. The es-1a keeps all the frequencies and especially bass well controlled.

Very good performance here, listening to the blues like Stevie Ray Vaughans live set at Carnegie hall “the things i used to do” you’ll really get a taste of his guitar - full-bodied, full of gritty blues distortion while crystal clear and very natural.

The same goes with a listen to Vivaldis “Spring” almost like hearing the sound of the violin for the very first time.

Listening to Phish “Ghost” from 9/1/17 at Dicks will give you one of the many renditions and funky bluesy jams with a fine balance between all the instruments and vocals. Want some more strings? give the string cheese set from 4/22/22 Ashville a listen specifically 'mouna bowa' and 'long journey home'

Speaking of vocals Janet Jackson “That’s the way love goes” and Ella Fitzgeralds “Summertime” both smooth as a babies bottom.

the treble is tuned very well. With the L500mk2s i found the treble a bit too much and very shouty. I was a bit concerned it might be similar with these but that’s not the case at all. Some base music was unlistenable with them for example Seven lions remix “you got to go”, but it’s just right with the es-1a.

Imaging and Soundstage:
I think the es-1a really gives you an opportunity to listen to music in a new way. Depending on the recording, sometimes the position eg in front of the stage row 1, or a few rows back can change depending on your source and even DAC (eg comparing r2r vs delta sigma). But regardless, i think certain Symphonies are a good way to experience that like Beethoven Symphony No 9 ‘Choral’ or any of the tracks from Lee Ritenour Rhythm Sessions or Ray Brown Trio Soular Energy

I’ve had the chance to listen to these on 3 different amps SRM3, Antares v3, Mjolnir Stax007tA. As they say some headphones (like the SR 007) do scale with a better amp, up to a point… i think these do as well, having listened on a SRM3 and an antares (similar to modded t1) i think the sound is much better on the latter. Not drastically better, but maybe noticeably better if you're 'critically listening' vs background music or listening for fun. i'd say 5-10% ‘better’ if you had to quantify it. And then on a mjolnir modded 007tA) maybe another 2-3% ‘better’. I put ‘better’ in quotes because i think it’s very subjective. i suppose you could also say a different flavor instead of 'better' if that makes sense.
like headphones or anything else in your chain after the source, the amps can give you a different flavor of the music. which flavor you like most is really up to you to decide.

I was a bit skeptical about the es-1a but after hearing them and being pleasantly surprised, they continue to grow on me and i like them more and more. Now trying to decide if i should keep these and let the 007mk2s go! I can see both the 007mk2 and es-1a as complimentary as many say and easily be the end game (combo or not) for many people.
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Thank you for your review. I owned this headphone for a brief time. While I did appreciate its technicalities, I don't agree that its meant for just about any type of music. I think I would agree that you CAN enjoy it equality for all types of music, sure, but the tonality is far from neutral and ymmv with different genres. I think perhaps the best word to describe the tonality would be 'dark'. The owner of the store is very trustworthy, so I don't think its a risky buy on that front. For the cost, it does get you very far up the ladder, and if you're a basshead im not sure you'll do any better than this aside from the 007. Its a step up from Jade II (just the headphone) in terms of technicalities, but far less neutral. Its a fun type of headphone and hard to beat for the cost.
any comparison with x9000 will be largely appreciated!


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