Campfire Solaris – A smooth exciting ride into hyperspace!

If you’re looking for an IEM with world class holographic soundstage, pinpoint precise imaging, quality bass (with subwoofer like sub bass), transparent mids and exciting while non fatiguing treble then you’re in for a very singular experience with the Solaris!


  • Speaker like presentation
  • Holographic soundstage with pinpoint precise imaging and top notch layering
  • Extended and exciting but non fatiguing treble
  • Rich, smooth yet articulate and transparent mids
  • Subwoofer like sub bass and bass with great control, detail and textures
  • All rounder, does well with any genre and is also forgiving of lesser mastering
  • Scales very well with an amp (low OI) and upgrade cables
  • Very good stock cable
  • Price is fair


  • Shells are big, hard to fit for some smaller ears
  • Bass attack lacking a bit with less powerful sources (low OI amp gives best results)
  • Isolation is very average even with deep insertion
  • Gold plating probably susceptible to scratches


By now, not much introduction is required for Campfire Audio, which is one of the highly regarded company building IEMs since 2015. Fairly recent, although ALO Audio has been around for a while. Maybe what’s less known is that Ken Ball was running a lab as a plant pathologist for the US Department of Agriculture when he decided it was time for a change (recommended read : From plants to Campfire Audio : the story of Ken Ball).

Ken literally started from his basement and as a self-taught engineer he is always « trying things not off the shelf, that normal electrical engineers wouldn’t think to do » . So Campfire is basically based on passion and trying out different things. It certainly turned out alright, in a short time span since 2015 quite a few unique and now all time classic such as the Lyra, the Andromeda, the Vega and the Atlas. There is certainly a Campfire house sound that is distinctive from other brands that can clearly be identified despite the very different approach between say the Andromeda and the Vega.

How does the Solaris (from the latin “Sun”) fit into the picture? The latest Campfire release and new flagship,  the Solaris is a hybrid design sporting one dynamic driver (10mm ADLC, probably the Atlas driver) for low and mids, a custom ported balanced armature for the mids and two armatures for the highs and a brand new super litz beautifully built 4 wires silver plated copper cable. The product pitch : « Solaris is the summation of our experience creating earphones and the acoustic technologies we’ve developed and discovered along the way. It delivers a sound that is second to none. Holographic presentation. Intimate detail retrieval. Soaring highs, engaging mids and impactful bass. Music sounds like music with lifelike performances, superior layering and unbelievable imaging. The traditional wall between high end two-channel hi-fi and personal audio just got thinner. »

Quite a tall order, isn’t it?Let’s see how it checks out!


The Solaris build is flawless, the 24K gold plated lid is a perfect match to the WM1Z body and as usual the rest is PVD finished with a stainless steel spout and the usual Campfire beryllium/copper MMCX connectors. Those are beautiful IEMs, the only question is how durable the gold plating will be, as it’s bound to be susceptible to scratch especially on the edges. Handle with care! Also, this is an eye catcher so depending on where you’ll be using them, be careful…

Fit and isolation

The Solaris shell are on the bigger side, protruding quite a bit from the ears, but luckily remain surprisingly light which means no strain while wearing them. This being said, the sheer size of the Solaris can be an issue with smaller ears and ear canals, and some had to return their units because of a fit issue. The nozzle like the Atlas nozzle is quite big as well and unless you’re like me blessed with larger ear canals deep insertion won’t be possible.

In my case, the Solaris is sitting flush, with full insertion and I am using one size smaller eartips. I have found the best fit and seal was the M size UE900 tips, and the comfort is on the high side. Of course your mileage may vary as it’s very much dependent on your own physiology.

I am not sure I understand why Final E tips are included as I found they affect the SQ, in general I’d stay away from any tip that has a stem narrower than the bore size. Isolation is good but nothing to rave about either (note that I am a low volume listener), probably a side effect of the lighter shell. I still consider this a good design choice as heavier shells would have affected comfort. Given the lightweight of the Solaris, the earhooks of the stock cable were not really needed there and negatively affect comfort in my opinion.


The Solaris have a highly engaging signature with a grandiose presentation relying on a great holographic soundstage with pinpoint precise imaging and an onion like layering. They feature lively treble, rich and articulate mids, a solid bass foundation all within a smooth delivery that make it non fatiguing with even the most energetic and/or busy genres. All of the above qualities make them fantastic all rounders that can give you great listening experience with a variety of genres. While Solaris will shine on better source material, it’s quite forgiving of lesser recordings, making it all the more versatile as basically everything will sound good provided you have a good source.

I am more a Jazz, Indie, Blues and Folk kind of guy and I was absolutely excited by the Solaris on those genres but I found myself listening to a lot more Rock, Metal, Dance, EDM and Dubstep than I would have thought when reviewing the Solaris. Initially meant to tests how it handled those genres but I took so much pleasure getting back to those genres that I ended up rekindling with entire albums altogether. I had a similar experience with the VE8 especially with Rock and Metal but the taller and deeper soundstage provided extra air of the Solaris helped listening for longer period of time and with more excitement. The extra sub bass presence and extension of the Solaris vs VE8 did also help there, as well as even more lively treble with more weight.

The first contact with the Solaris had me totally « wowed » by a few key items :

  • its soundstage depth and height with a very holographic rendering
  • Its pinpoint imaging, with some ahah moments on well known tracks, things seemed to fall into place way more precisely and naturally
  • Its treble, I have never heard Andromeda but the lower treble tuning is both exciting and non fatiguing, hi hats have never sounded better

I can see your reaction « but why isn’t the bass in there? » as many would expect something very special with the driver from the Atlas, with a lot of wowing power and impact. Well, this wasn’t what initially struck me. I value my first impression even if the unit was not burn in those raw first minutes will usually be interesting nonetheless.

Ken recommends at least 5 or 6 days for the dynamic driver to be fully burnt in and given my experience with the Vega I knew this was clearly something to keep in mind. Here is the surprise though : even out of the box, the Solaris didn’t sound « unruly » as its Vega brother. The bass clearly has good control out of the box, with great textures and detail. If anything the bass out of the box is almost too sensible, I found myself wishing for more impact.

Let’s dive into this a bit more…


The bass is well extended with subwoofer like sub bass, with no saturation even on the most sub bass heavy tracks. The LCD i4 is the only other « IEM » that provided a similar experience in the sub bass. But the Solaris has in my opinion even better bass than the LCD i4, there is more detail and control, probably also by way of a cleaner bass tuning with less mid bass emphasis. The flipside is that you loose some oomph factor in the mid bass and I won’t lie, I wished it had a tad more impact. You can’t get it all and the bass quality is off the charts with the richest bass textures and layers I ever had the pleasure to listen to. This is especially important when listening to classical or Jazz where for instance double bass sound as good as they ever will in my opinion. There is a very tactile feel to the bass. Burn in definitely made bass tighter and after a 100 hours or so I didn’t notice further improvements.

The Solaris bass is in my opinion bass done right, but bass-heads might better go the Atlas or Legend X way as bass quantity and impact might be found lacking depending on the genre you listen to but also on your source. The above is true with WM1Z (firmware 3.0) but several listening sessions with the Mojo gave me a hint that other sources might provide different synergy and results. More on this in the Sources matching section.


The Solaris mids are very musical striking a very nice balance between articulation and smoothness and the right amount of body and weight to have presence but not too much in order to keep the right separation. Vocals are just slightly forward enough to be in front of the instruments but I wouldn’t call the Solaris forward by any means. This is subtle. Timbre is very natural, with a slightly warm tone that makes the Solaris very musical.

The lower mids are emphasized just enough to give male vocals satisfying power but not overly so as not to lean towards a darker signature. The upper mids on the other hand are clearly tuned for smoothness, but are neither recessed or muddy as the Solaris has good clarity and female vocals are beautifully portrayed with a touch of sweetness. There is no hint of sibilance whatsoever even with the worst tracks I had handy. As across all range, layering is great. There is a richness to the sound and an overall sense of realism and accuracy.

I find it very interesting given the profile of the mids (neutral warm) that Jazz and Classical sound so great, as usually thinner sounding IEMs fit the genre better. The Solaris is not thick per say but it does have body and weight combined with a lot of air, separation is more by way of its vast soundstage so it doesn’t need to rely on a thinner signature to make complex music sound articulate. On top of this, contrary to the bass and treble, I found the mids have interestingly a sharper attack with more snap, you get satisfying crunch and whack.

There is clearly something unique there that feels so engaging to me.


The highs are very exciting while never harsh or hot, both attack and decay are smooth. There is plenty of detail and a lot of sparkle, contributing greatly to the engaging nature of the Solaris and bringing a lot of air. Treble is not slow but nor is it the fastest treble around but it has distinctive weight and body making it also very “tactile” (for lack of a better word). Percussion have never sounded better to me, and hi hats are really something I never thought I’d enjoy so much. It’s the first IEM since the VE8 that has me wowed by treble… Last but not least, note linger beautifully when called for, somewhat reminiscent of my experience of Final Audio Heaven VI. In my opinion, the Solaris treble are key to the emotional nature of the IEM, as well as bringing balance and excitement to a very smooth signature.


With the Solaris, Campfire Audio has built what will undoubtedly become as much of a classic as the Andromeda, living up to its quite bold promise « Holographic presentation. Intimate detail retrieval. Soaring highs, engaging mids and impactful bass. Music sounds like music with lifelike performances, superior layering and unbelievable imaging. The traditional wall between high end two-channel hi-fi and personal audio just got thinner. »

In Star Wars : A new hope, Han Solo said « Traveling through hyperspace ain’t like dusting crops, boy! Without precise calculations we could fly right through a star or bounce too close to a supernova and that’d end your trip real quick, wouldn’t it?». To me, buiding an hybrid is a bit like travelling to hyperspace, it’s very easy to go wrong and quite hard to build something as highly coherent as the Solaris. Metaphorically speaking, I am glad Ken did his calculations right and propelled us into hyperspace, and the trip is nowhere near its end there are many galaxies yet to explore and countless hours of fun.

Never had an IEM sounded so speaker like in the way it presents music, a big sound much more akin to full size open back headphones than any IEM except the LCD i4 which is arguably not really an IEM with its 30mm planar driver and his open back. It’s no small feat to have accomplished such soundstage and imaging with a closed back IEM, very few have managed this (U18t comes to mind) let alone on the warmer side of the force. This combined with a smooth and engaging signature help the Solaris bring you into the music and when you realize that you’re more often than not forgetting time and space, you know something special is happening.
If you’re looking for an IEM with world class holographic soundstage, pinpoint precise imaging, quality bass (with subwoofer like sub bass), transparent mids and exciting while non fatiguing treble then you’re in for a very singular experience with the Solaris (actually the first title of this review was : It’s a kind of magic!).

If you’re looking for a bass-head experience, a good low OI amp will help but you’ll probably be best served looking towards the current kings namely Atlas or Legend X as I don’t believe EQ’ing or a bassier source will change this for you without loosing the distinctive bass qualities (detail, textures, layering) that in my sense make the Solaris pretty unique.

This review was initially published on headfi :

Solaris review on head-fi frontpage (8/11/2018)

Disclaimer : I have purchased and paid the full retail price for the Solaris, this is not a sponsored review.

Listening notes : I have listened to the Solaris for over 40 hours before writing this review. The unit has been burned in almost 24/7 for over 7 days (so approx 150 hours). While I mainly use a Hansound Zen (full copper) balanced cable to enjoy the Solaris to the fullest, I have stuck to the stock cable for the purpose of this review. The vast majority of my time with the Solaris is with Sony WM1Z (unit has over 300 hours on it and running firmware 3.0) but I have included select comparisons with other sources such as Mojo, Oriolus BA300S and ALO CV5


The Solaris is delivered with a nice printed card box containing the following accessories :

  • Campfire Audio Premium Leather Earphone Case
  • Earphone Protection Sleeve
  • Super Litz for Solaris (Silver Plated Conductors featuring multi diameter stranding with Berylium Copper MMCX and 3.5mm Stereo Plug)
  • Final Audio E-Type Tips (xs/s/m/l/xl) – Campfire Audio Marshmallow Earphone Tips (s/m/l) – Silicon Earphone Tips (s/m/l)
  • Campfire Audio Lapel Pin
  • Cleaning Tool


  • Dual Custom Balanced Armature Drivers + T.A.E.C. (High)
  • Single Custom Ported Balanced Armature Driver (Mid)
  • Specially Tuned 10mm Dynamic Driver (Mid + Low)
  • 5Hz–20 kHz Frequency Response
  • 115 dB SPL/mW Sensitivity
  • 10 Ohms @ 1kHz Impedance
  • Less than 1% Total Harmonic Distortion

Source matching

All of the above impressions are from WM1Z with firmware 3.0. I have also tried the sources below :


Note : I ran the DX120 with reference sound mode and super slow roll off filter, with the stock cable balanced.

This was an interesting pairing, quite different from WM1Z, a leaner more reference sound with a twist as the DX120 has more mid bass than the 1Z (with firmware 3.0) providing more kick there and more treble sparkle as well thanks to a colder tone than the 1Z. The lower mids are leaner, making for a cleaner but less musical presentation to my taste, I prefer a fuller sound, but I am nitpicking and that’s really an unfair comparison to begin with.

If you’re into a reference musical signature, the DX120 with the Solaris will be a highly portable combo. I think that the DX120 is not too far off from the DX200… not really as pure reference as AMP1 but not as warm as AMP3 either.


Mojo has more mid bass so you do get some extra kick which no doubt will satisfy bass-heads better but to me you loose in the exceptional detail and textures that makes the Solaris shine in terms of bass quality. There is more lower mids and upper mids are smoothened a bit which make the Solaris warmer, darker and less articulate. The Mojo loosing at least 20% soundstage vs the 1Z also affects the separation making it a less than ideal pairing especially for Jazz and Classical. A lot of the WM1Z / Solaris magic is lost there. Treble looses quite a bit of sparkle compared to the 1Z, it’s good but nothing to rave about.

Oriolus BA300S

With the Oriolus BA300S plugged into the WM1Z, things get interesting as the BA300S extra power is significant with 700mW into 16ohm while the balanced output of the 1Z in high gain tops out at 250mW into 16ohm. That’s on paper, how does it translate in real usage?

Short answer is, the Solaris scale very well even with this mid tier tube amp which again shows that even low impedance and high sensitivity IEMs can benefit from extra power. With the BA300S, the Solaris clearly enjoy extra driving authority in the bass department, scratching the little itch for more bass impact with a bonus of even richer textures and detail similar to standalone WM1Z. This could probably also be credited to an even lower output impedance of 0.3ohm for the BA300S over the 0.94ohm of the 1Z.


The Continental v5 is another step up the ladder source, with high grade ESR capacitors and a 16V power supply providing a +/- 8V voltage swing. It’s also more versatile as it allows for tube rolling and while the baseline amp signature remains consistent you can tweak it significantly enough to adjust pairing with your IEM.

Compared to the Oriolus BA300S, running with the 1Z the CV5 demonstrate greater authority yet and although it’s not a balanced implementation the soundstage is significantly wider and a little deeper. There is significantly less hiss than the BA300S as well. With the default 6111 stock tube – same as the BA300S – the presentation is tighter in the bass, mids are leaner with less body a very clean presentation and the treble is both better extended and more refined. I found myself wishing for more weight and body and a bit of warmth that I do have from the 1Z alone. This is even more striking with the DX120 as source for the CV5.

I rolled to the 6832 tube and this is a much better pairing with the Solaris, significantly more bass kick and mids are fuller with satisfying body and weight and treble tone is more pleasing. Textures are also a step up from 6111. Overall not that much warmer than the 6111 though but much more musical to my ears. This is a fun combo with a lot of energy. Switching to CV5/6832 with DX120 as a source, definitely more kick in the bass but more treble presence as well and leaner mids than from 1Z.

The best sounding combo source for the Solaris so far has been WM1Z with the CV5 (6832 tube), you basically retain the 1Z qualities adding quite a bit of headroom which benefits the macro dynamics significantly, the CV5 being quite the lively amp to begin with. Soundstage gains another 10% or so compared to 1Z alone, making for an even grander sounstage. The 1Z alone is a tad more laid back and will be the preferred set up for late night listen.

Upgrade cables

All of the above impressions are from the stock cable, single ended. I have purchased a balanced Hansound Zen 4 wires in 2.5 termination that I then upgraded to 8 wires copper cable with 4.4. termination. All of the impressions below are from WM1Z balanced out in low gain :
First of all, the Solaris does respond well to be run balanced, soundstage and imaging are further improved with better separation. I’ll soon post comparison with the stock cable balanced as Campfire kindly provided me with one when I asked to order an upgrade.

Hansound Zen 4 wires balanced

With the 4 wire Hansound Zen, bass is a bit tighter and more textured. Note that the Hansound Zen has a subtle effect on the signature compared to the stock cable, it’s not a colored cable that makes the Solaris much warmer or bassier. It’s fairly transparent with the following improvements : bass has a bit more impact and is a bit tighter overall, mids are largely similar to the stock cable with slightly more body and highs have a little less sparkle and a tad warmer tone. I find there is good synergy for my taste.

Hansound Zen 8 wires balanced

The 8 wires Hansound Zen improves this much further up to the point I wouldn’t even consider it’s in the same tier as the 4 wires. It probably has to do with a much lower cable impedance that 8 wire design usually features and the Solaris responds very well. I had to lower the volume by 10% to achieve the same SPL. On the downside there is a noticeably more hiss, but nothing that would affect the listening experience other than critical listening on very very quiet passage in tracks.
With the 8 wires, the soundstage is wider and taller but more importantly much deeper. Bass is more layered and has gained even more textures, it was already very good but the 8 wires takes it to elite territory. This is something to behold. Both macro and micro dynamics are also in a different ballpark and quite honestly I am reaching the levels of SQ that I had never experienced so far with any gear I have owned. The Solaris sound even more like a full size headphone, so open, that my brain is reconciling the sound is coming from IEMs. Transparency and clarity is also better and the Solaris show its technicality a little bit more.

Bonus : Select comparisons

I can only compare with what I own or have owned long enough (several hundred hours of listening) but here are a few select comparisons. Unfortunately I have never owned or auditioned Andromeda so this much expected comparison will have to wait for other reviewers to chip in!

LCD i4

There are some commonalities between the Solaris and the LCD i4 : a huge soundstage, great sub bass extension, smooth signature. Granted the LCD i4 edges out the Solaris in terms of soundstage, but not by much which is quite a feat. Sub bass extension is similar although the Solaris has more impact due to its closed back nature. The LCD i4 has more mid bass the Solaris has cleaner more articulate bass with more detail, while the LCD i4 has a tad better textures and a clear advantage in speed.

The Solaris mids are more transparent than the LCD i4, with leaner lower mids and upper mids are clearer and more articulate providing more bite as well as more detail. The LCD i4 is warmer. Treble are very different, despite being similarly extended the Solaris is much more exciting by way of its lower treble tuning. To me the Solaris is much more engaging, the LCD i4 missed out on the opportunity to have more articulate mids (upper mids are too smoothed out) and more treble sparkle.


Both the VE8 and Solaris are fantastic all rounders with a very musical and smooth tuning. The VE8 is faster, with shorter decay. Mid bass is more prominent on the VE8 with better kick but sub bass is better extended on the Solaris with that subwoofer like quality. Both have a smoother attack, neither has hard hitting bass. I think the Solaris bass is overall more balanced with leaner mid bass and more sub bass presence.

Mids are interesting, the Solaris is slighgly warmer than the VE8 I find a tad more lower mids on the Solaris and on the flipside a tad more upper mids on the VE8. Notes are bigger on the Solaris, there is more space between instruments by way of its soundstage which is considerably deeper but similarly wide. Maybe the VE8 is a bit taller there. The VE8 has slightly more body and weight, the Solaris mids on the other hand breathe better. Both have highly coherent mids, no strange peak and a smooth experience.

Treble : both are sublime but with a different take. The VE8 treble is smooth and has good sparkle, with great speed it’s airy and feathery a very delicate and refined presentation of the treble. I’d say upper treble are as good as it gets and lower treble is tuned for sparkle with just enough excitement. The Solaris has more weight to its treble, but it’s not as fast.

It’s an exciting treble with an emphasis on lower treble while upper treble while very very good takes a back seat to the excitement and sparkle. IMHO the Solaris walk a very fine line pushing treble excitement as far as it can while never sounding harsh or fatiguing… The VE8 was the first IEM that made me realize I loved good treble. The Solaris does the same, showing me another path to exciting and smooth treble. This makes both IEM very emotional.

Phantom (Custom)

This will sound strange as it’s BA vs DD but I find although it doesn’t extend quite as low as the Solaris, the Phantom has more bass impact thanks to sharper attack and more kick in the mid bass. There is more rhythm to the Phantom, it’s more physical while the Solaris is more mature with a more refined bass presentation providing more detail and textures.

The Phantom mids are thicker, warmer and more forward. It has a tad more lower mids, but more importantly the Phantom has upper mids tuned for clarity : a necessity given the lesser treble sparkle, that prevent the Phantom to fall into darkness so to speak. The Phantom mids have more power and their presence is felt while the Solaris has more transparent mids with upper mids tuned for smoothness as the treble is providing the air and clarity to its signature.

Both the Phantom and Solaris have unusual weight and body to their treble, but the Solaris has much more sparkle and it’s treble tone is brighter than the Phantom. The Phantom lower treble is much more conservative where the Solaris is playful. The Phantom engages you with its bass kick while the Solaris is giving you shivers with its treble.

Solaris separation is better than the Phantom while remaining just as coherent there is simply a lot more air by way of its much bigger soundstage.  Imaging is great on both but simply sounds better because the image itself is much bigger and deeper on the Solaris.


The EX1000 is brighter than the Solaris, those are two different signatures. The EX1000 is more neutral bright to my ears while the Solaris is neutral warm. The EX1000 can be a bit harsh at times (although a copper cable will help), the Solaris is as smooth as it gets. Both have a high level of detail but the EX1000 is focused on sharpness and Solaris on smooth delivery. Both have great extension, the Solaris has more kick in the bass but they share good bass texture with a high degree of naturalness. The EX1000 is faster with quicker decay.

The Solaris mids are thicker there is more body and weight and lower mids have more presence. Both have great articulate mids but the EX1000 upper mids are clearly more prominent.

The treble is very extended on both, but the presentation is very different. The EX1000 is thinner, with more upper treble presence, it’s a airy treble with quicker decay. Resolution is better on the EX1000. The Solaris has weight in the treble, it’s has more texture and has more impact. Lower treble is more prominent on the Solaris but always smooth and sibilance free contrary to EX1000.

Both share a great soundstage, I think the EX1000 is wider or appears so because it doesn’t have the great depth of the Solaris, also the Solaris soundstage is taller and overall more holographic. The Solaris is bigger sounding probably also thanks to that deep reaching sub bass.

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