Think high end headphones? Sennheiser HD800, Audeze, Fostex and maybe now even Mr. Speakers. Think even higher end than that though and your mind probably wanders too JPS Lab’s Abyss and Stax. Yes Stax, that elusive high end company that play with a type of technology that is very unique to them, electrostatic drivers to be more precise. What people don’t realise is that while Stax have been the leader of that technology for a while, for the last few years KingSound have been kicking around with their rendition of a electrostatic headphone. These guys may be new to the portable realm but when it comes to electrostatic transducers they have been using this snazzy tech in full sized speakers for quite some time now out of their base in Hong Kong. Like a lot of speaker companies the transition into headphones seemed like a natural and obvious one and with them already having a true grasp of how things work with the drivers, it was just adapting. Where KingSound differ to Stax is that while Stax cover a range of prices from entry level to the very high end, KingSound try and keep their prices a bit lower, not exactly cheap but not near the realm of the SR-007/009. There latest release the KS-H4 is the most costly at $900 and the KS-H3 we have is a touch cheaper at $875. At roughly £600 this is certainly at the cheaper end of experiencing electrostatic headphones. Now the names of KingSound are simple, we have a H1, H2, H3 and H4 and simply they are the order they were released. So why am I not reviewing the H4, the latest and flagship of KingSound, well because I didn’t want it. Me and Josh tried it at the Munich High End Show and had no luck sealing with it, the design did not have rotating yokes and the bottom of the pad did not sit on your head, what a shame.


ESL Talk

Being electrostatic you of course have the fact you can not just plug them into your current headphone amp or phone and get sound, they have to have their own specially designed and biased energiser and the H3s I have can be used with Stax products but KingSound also make their own range of amplification. As of now they have 3 choices for amps, a cheaper solid state M-10 ($625), a more expensive OTL tube M-20 ($1,800) and finally a new portable option that has the ESL output for electrostatics and a standard 3.5mm output, the M-03 ($450). I have the latter two options so can get a taste of trying different amplification with the headphones, which will certainly be interesting, especially with the rather huge price difference. Worth mentioning and really cool is some of the bundle deals Moon-Audio in the US do if buying a combination of products much as along with the M-20 tube amp, the KS-H3 are only $350 extra, thats quite a saving!

Electrostatic headphones with their very thin membrane drivers tend to have high impedance (H3 is 113kΩ and in that mindset, OTL tube amps have always worked quite well with them and that is exactly what the M-20 amp is. Its 2x160Vrms output translates to 10.5wpc into these headphones and that means it has a lot of grunt to put out, although the little M-03 is no slouch with its 300Vrms output for electrostatic headphones but is a fairly weak 125mw into 32ohm headphones from its 3.5mm output. The M-30 amp has quite an array of tubes, utilising 4 6P15s, 2 12AX7s and a 6V6 output tube. Yes this has 7 tubes and will get hot. Also worth noting is that you can roll the tubes, I know Moon offer an upgrade tube option and if you have the knowledge you can roll to your hearts content, while I did with the Lampizator review, I have not had time this time round. As for the M-03 I cannot find much more info beside simple specs and I do not see a huge gain of me opening it up. That being said on top of its two outputs, it has a single 3.5mm analogue input and then a standard USB micro B.  Then it also has a full sized USB output in case you want to charge your phone our source, odd feature.

Sturdy Enough?

My first concern for these is the build quality. Although they are at the entry level pricing for electrostatics, in the bigger picture these are still higher end headphone equipment, especially the M-20 at almost two grand US. The headphones themselves are very light, which is only a good thing when wearing but looking closer at the build quality it does not ooze that premium of similar priced equipment, not the Audeze EL-8 (regardless of whether I actually like the sound of it), ZMF Blackwood (which is DIY to an extent) or any number of Sennheiser models from the HD600 upwards. While thankfully there is metal in the design, and the exterior of the cups are finished lovely and are very solid, the yoke is plastic then the headband itself is the suspension type with two strips of metal over a very thin synthetic leather rest, the Blackwoods is real leather and much thicker. On top of that the suspension is plastic and does not install much faith for longevity. The cables are not removable and while they are in the new H4, that has its own problems to worry about. Having a 5 pole output the cables have 6 signals per channel but instead of being in a neat braid, they are glued side to side in a cheap looking manner. After the y-split we have 7 wires side by side for a big flat cable, but I do worry about them splitting apart. My worries continue when it comes to the wearability. Once again the materials of the pads feel cheap and they have no depth to them, so your ears are pressed right up to the drivers for an almost superaurual feel which gets very stuffy on longer listening. Lastly and similar to what I mentioned about the H4 that do not swivel on their hinges, these fold flat but do not rotate the opposite way at all so I still do not think they seal at the bottom as well as they could, in a comfort sense as I am still sealing sonically. Overall I am being fussy and these don’t have huge problems but it is just clear that these guys are new to headphones and they could do with a few tweaks. That being said entry level Stax are not the best built.

Elaborating on the comfort I think these are still very easy to wear because they are just so feather weight and while I dug out the headband it is nice on your head. My only problem is the close proximity of the pads on my ear, it gets sweaty and itchy over time and i really wish there was not a cm gap at the bottom of the pad between it and my ear.

The M-20 doesn’t so much have real problems but does not have any sense of luxury to it. The decision on shape is unique, at least for a headphone amplifier, going for a thin and long aesthetic. The lack of quality comes in the parts, especially that of the ones you touch such as the volume pot, that does not have any more quality than budget amps like the Objective 2, no stepped attenuator, no sturdy knobfeel. Then you have the odd decision to be put the power button on the back, thats a pain to always have to reach over the length of this amp to get to it. Then you have the grill that sits over the transformer and tubes, which I leave on (even though it gets very hot) but if you to take it off, it is flimsy and doesn’t slot back into place with any ease what so ever. Oh and the feet are slippery and skid all over the place.

The M-03 seems like a real turn around in quality and it is a chunky and firm portable amp. The volume pot is of decent size and has a nice resistance to it and the weight of the amp gives serious confidence. Considering this will be something for use on the go (not that the H3 are portable headphones being open backed) it is nice to see them concentrate harder on the build. It looks slick as well and you can get it in funky colours if you so need.

Warmth and Speed

If you have heard a top end Stax, say the SR-009 then you will note it is a lightning fast sound that may be on the bright side and puts things like details first. While there are obvious exceptions to all types of sounds, there are qualities you expect with a respective technology, be it dynamic, planar magnetic or electrostatic from my experience with a lot of Stax models. While I do get a feel of that transparency and speed from the H3, this seems to render bass in a much more solid way than I have ever heard from a Stax, even more so than the warm sided 007. For quick clarification when I talk about the sound it will be with the M-20 and we will go over the M-03 a bit later. Maybe the tubes are a little responsible for the warmer tonality of the H3 but as the KingSound system that is still the sound they have aimed for and you know what it is very pleasant. While the bass is powerful with a good level of depth to it the rest of the sound is still clear and very detailed, as one would expect from an electrostatic.

When it comes to decay the bass actually turns a blind eye to what electrostatics have done in the past and we have enough linger to easily classify this as a warm product. It is the mid-bass were this headphone really flaunts its stuff, it has a lot of body here and can really come bellowing in, these are easily bassier than a lot of my very best headphones such as the HD800, ZMF Blackwood and Beyerdynamic T5p although it might not quite have as much quantity as my HD580s. That being said when it comes to extension these do leave a tad to the imagination, it is not necessarily bad and everything feels quite weighty, but by 50Hz things are already very faint, the roll off probably starts at 100Hz. Even with a bit of a bass roll off, the bass is surely one of the most lovable things about these headphones, it is rich and engaging and its softer nature is very easy on the ears.

While there is no doubt these are a fantastic headphone, to me the midrange is the areas that prevents me going full blown mad over the value as I find it off tonally. It can be a bit wooly due to an upper midrange, lower treble drop off, from around 4kHz and it causes a weird resonance in the mids. The decay of timbre feels a bit excessive at times and both sexes are effected in terms of vocals. With that caveat out the way they are still very much in the mix of the frequency response and it still sounds more even than the EL-8. I do think as well that the body seems impressive, not as whispy as some cheaper Stax but still with that sense of finesse that is very electrostatic.

Too finish of a sound that is not typically electrostatic these are not even that bright, they have a little sparkle from a 10kHz peak but apart from the the higher ranges are syrupy and sweet with not even an ounce of sharpness to them. After the lower treble slight absence the presence is solid and so if the overall sound of them, not being as strident as the HD800s is just one of the positives.

Soundstage in general I am quite spoiled for referencing the HD800s and having such an enveloping DAC as the totaldac d1-tube-mk2 on hand and I have found the soundstage very average at this sort of price for the KingSound system. It is not as distant as the auditorium like Sennheisers but still remains away from your face and the slightly audible background combined with soft and relaxed nature of the headphone leave a touch to want in terms of pin point accuracy.

At this price point in terms of sound alone I think this does very nicely, I prefer it to the Audeze EL-8 and Oppo PM-2 but the trouble does step in that while it is a similar priced headphone, this does need a specific energiser for it and there is not a huge chance of having one of them lying around meaning the price does go up. For that reason it starts to turn up in HD800 territory and I just find them so much better tonally, it makes these sound a bit off and also a bit cramped, although the KingSound bass does give it a lovable quality in the match up. That being said this just is not on the same technical level if a different sound signature.

Electrostatic on the Move

Switching to the solid state and slightly weaker M-03 amp and the sound does certainly take a shift to the colder side and the soundstage gets flatter and wider. That being said the M-03 as if to prove that the M-20 is not the reason for the bass, we still have a full low end off this amp, it just doesn’t have the same level of control, in fact that goes for the headphone as whole with this amp, it much more easily becomes messy and jumbled. That being said I do feel like we get a little bit of zip back in the upper mids and makes them sound much more level. I also find this amp to sound harder with better dynamics.

Being a portable amp I thought rude not to try out with a few pairs of my IEMs but did not get very far due to having quite a considerable amount of hiss that I could easily conclude would prevent anyone from using this amp with their earphones. I also have found the gain to be ridiculously high, the least sensitive headphones in my collection, the ZMF Blackwood get loud with just the smallest turn on the volume pot and low level listening would equal a channel imbalance. That being said I don’t find the Blackwoods to sound particularly bad off the amp and at least they don’t hiss like my IEMs. That being said the way the gain works I think the 3.5mm output is more of an after thought but half me thinks who cares, this is a portable electrostatic energiser, so yes, it is just a cool lil bonus you can try it out with your other cans. I think this amp is a well made piece of gear that should only be purchased for use with your KingSound headphone in the office, or if you plan on taking them to different locations quite often and then you get the fun of seeing if it does do alright with your other headphones, because it certainly has the gain and power to drive most of my harder to drive headphone at the cost of hissing with anything sensitive.

A Great Entry into Electrostatics, Just Without Polish

The conclusion title says it all really. I find the warm sound is a very nice place to start for electrostatics and you still get some of the trademarks qualities such as finesse and speed. Its a strong combo. Now that being said they are not cheap and I do not think the tonal balance is top tier, even with the fairly expensive tube energiser. Without the Moon bundle deals I would feel the price is a too much of a stretch but they really help push the value of these and make them some thing perhaps worth consideration and it is a shame they are not for sale in the UK with similar combo deals. I have not tried with the solid state desktop amp but if you really don’t want to pay a lot to get a feel for electrostatic technology, the lil portable M-03 with KS-H3 does reveal a lot of what is capable here and you will also have a clear upgrade path which is cool. I hope KingSound keep at this game, giving products a more luxurious feel, comfier wearability, better ergonomics and a little fine tuning on sound because I think they could end up in a very good position.

Sonny Trigg