Oriolus Traillii

Small IEM with a BIG Sound!

PROS: hybrid (8BA/4EST) design with a natural full body detailed tonality, powerful bass impact, and a balanced sound sig, 3D holographic soundstage, durable compact shells, premium PWA cable, VanNuys carry case.

CONS: price, universal fit only, nothing to nitpick unless you prefer a different sound sig.

The product was provided to me on a short loan from MusicTeck for the review purpose in exchange for my honest opinion.

Manufacturer website: Oriolus Japan.  Available for sale from MusicTeck.


The only time I use preamble in my reviews is when I talk about cables because I find that discussion to be a rather controversial topic which needs some additional explanation before the Intro.  So why would I start IEM review with a preamble?  Because I need to address the elephant in the room, the price tag of Oriolus Traillii which is $6k.  When I heard how much it cost, a thought ran through my mind that we crossed yet another price threshold and now entering a new chapter of premium IEMs.  But is this really a new chapter?

Every time I review flagship IEMs, I get asked about different premium cable pair ups.  And some of my readers are well aware of Nic’s thread on Head-fi where I see a lot of discussions from head-fiers who use their kilobuck IEMs with high end cables.  The price of Traillii is not for everybody, but there is a number of audiophiles who already own $5k-$6k IEM/cable combos because they want to squeeze out every ounce of performance, don’t mind diminishing returns, and still find it cheaper than 2 channel home systems where a power cable alone can cost as much.


So, let’s put down pitchforks and torches, and if you are still curious about this new IEM release from Oriolus with a premium PWA cable, proceed further to read my review of Oriolus Traillii latest hybrid flagship.


Actually, this review feels a bit like a déjà vu from 2018 when I visited Oriolus/Hyla table at CanJam NYC and heard Oriolus Mellianus for the first time.  I couldn’t get its tuning out of my head and just had to review it.  Now, 3 years later, I continue to use and to feature Mellianus in a number of my reviews as part of comparison and cable pair ups.  Fast forward to 2020, and I saw the announcement from MusicTeck about a new Oriolus Traillii flagship which of course caught my attention even before I read the price.

My original plan was just to hear them without a commitment to review, and I was happy for the opportunity to spend a few days with Traillii.  While I’m trying not to use the word “spoiled”, I do feel a bit jaded after having a chance to hear and to review so many different flagship IEMs, to the point where it is hard to get excited about another one.  And as usual, I didn’t know what to expect, but after putting these in my ears, I immediately asked MusicTeck if I can hold on to them for a few extra days so I can write full review.

Another interesting thing was Traillii being released under Oriolus and not Hyla name.  For those who are not familiar, Oriolus was formed in 2015 under the umbrella of Cyras Co. in Japan, and had a number of successful IEMs, DAP, DAC, and Amp releases.  In 2017, Cyras added a more upscale line of IEMs under Hyla name, though this latest premium flagship release ended up under Oriolus name.  But regardless of the name, what really counts here is how this little bird sings, so let’s proceed to find out more.

Unboxing and Accessories.

Arrived in a smaller size plain carboard box, inside you will find a custom VanNuys storage carry case which is pretty much the whole packaging of the product.  VanNuys (Japan) are well known in audiophile world and usually hard to find outside of Japan.  This ballistic nylon multifunctional case with Oriolus name on the cover has a padded poly mesh inner lining and adjustable velcro partition to make a separate pocket for storage of other accessories like eartips.  Plus, it comes with a twin-tube double sleeve (in red) to separate earpieces so you can keep them apart and secure during transportation.  Though I do like VanNuys storage case, it is not exactly pocket friendly.

Other included accessories are a set of S/M/L regular wide bore silicone eartips, a set of M size double-flange eartips, and a set of S/M foam eartips.  You will also find a cleaning tool, and a removable cable shirt clip, though the spring-loaded mechanism to attach to the cable won’t work with the included thick PWA cable.  I assume this cable clip is a standard stock accessory for use with thinner cables.

Overall, the packaging and accessories are practical, but at this price the unboxing lacks a wow-factor.


The stock cable is a customized version of a popular PWA (Peter Wong Audio) 1960 4-wire (8conductors) cable which retails for over $2.2k by itself.  As I mentioned in my EE Odin review where they also used PWA 1960, these cables are quite popular and in demand even considering their premium price.

The cable uses 26AWG gauge wires and FEP jacket for a positive signal (as part of the core) and 24AWG gauge thicker wires and PVC jacket for a negative signal (as part of the shielding).  The wires are insulated and combined under a tightly braided black carbon fiber sleeving which has a nice touch and still feels very flexible.  Don’t expect a see-through jacket which showcases the wire.  This cable is not about pretty looks but performance and isolation, using UPOCC Litz Copper premium wires presumably sourced from Cardas.

Since positive and negative signal wires are combined under the same sleeve inside of a coax cable design, you can only see two Left and two Right wires, thus a name of 4-wire cable, but you have a total of 8 separate conductors, 4 on each side.  The cable comes with a brand name genuine Pentaconn 4.4mm plug, carbon fiber black y-split, and PWA signature wooden round chin slider designed to minimize microphonics effect.  Toward the connectors you have a flexible clear heat-shrink earhook going into PWA 2pin connectors with red/black ring marking and red/black short strain relief to indicate Right/Left sides.


Before I go into the design details, I want to point something out.  Often, people make assumptions that a flagship IEM should have a fancy look.  If you Google “Traillii” you will see that it is a type of a small flycatcher bird that looks rather plain from outside, until it starts to sing.  As Wikipedia says “… their song is the only reliable method to tell them apart in the field” from other similar birds.  That pretty much describes how I felt about Traillii when I put these small shells in my ears and let them sing!  Don’t know if this is what Oriolus guys had in mind, but it sure does make sense to me.  While Traillii doesn’t look as flashy, once you hit Play you will hear a BIG sound.

The IEM itself has a 12driver design with a 3-way crossover that partitions drivers into 2BAs for lows, 6BAs for mids, and 4ESTs for highs.  And despite 8BAs and quad ESTs along with voltage transformers, everything is squeezed inside of a very compact clear shell with a unique brownish/reddish faceplate finish covered in hairlines of fiber strands.  Oriolus also offers a selection of 36 alternative custom faceplates, but they do have a warning it will delay availability of Traillii if you decide to customize it.


What is interesting, despite packing a more advanced hybrid design config inside, Traillii shells are nearly the same, and maybe even a touch smaller than all-BA Mellianus.  The body of the shell is made using Photopolymer material, and as I already mentioned, the shell design is very compact with a transparent body and standard universal faceplate selection which can be customized.  The nozzle is a bit thick and shorter, has a secure lip at the top, and has one large bore opening and 3 smaller ones.  Also, 2pin socket is recessed, just like in Mellianus.

The fit was very comfortable and secure with stock eartips, and with shells being so lightweight I didn’t even feel them in my ears.  I do know that some people prefer CIEMs, but I’m not aware if one is available for Traillii.

The fit.


Page 2 – Sound analysis and Eartips selection.
Page 3 – Comparison, Source pair up, and Conclusion.

25 thoughts on “Oriolus Traillii

    1. Hey I’ve been following your reviews for a while. It has really helped me decide what TOTL IEM I should get for my next purchase. So thank you so much! I really do appreciate the effort and level of detail and the comparisons made. I have bought the Final A8000 and have had it for almost a year. There was nothing wrong with it but when I compared it to the Sony Z1R I found I preferred the bass on the sony. The Z1R also had a similar sized soundstage but not as much clarity, especially in the mids.

      Because my top 2 priorities are bass and soundstage I preferred the Z1R. Alex I was wondering if even by memory, you could give me a comparison between the A8000 and the MMR Thummin in the areas of sounstage and dynamics of the bass?

      Thank You Very Much in advanced!
      Thanks for your effort and your time.


      1. It’s hard to recall soundstage by memory, and tbh, unlike some other people I didn’t find Thummim soundstage to be that big. Maybe it is because of its thicker warmer sound tuning which to my ears has the effect of more intimate rather than 3D holographic space. The more revealing airy nature of A8k gives its soundstage more width, but like I said, all could be a matter of perception. Regarding bass, it is literally NIGHT and DAY, Thummim is almost bass-head tuned IEMs while A8k has nearly flat bass in a relative comparison. A8k bass is about accuracy, about articulation, about speed and precision, while Thummim bass is BIG and BOLD with a deep thick sub-bass rumble and big mid-bass impact, and slower attach and shorter decay of bass notes. I’m going by memory, but that was the impression it left me with. Two completely different IEMs. Another one, Odin is fantastic, and will have more bass impact (than A8k), big soundstage (like A8k or maybe bigger), and similar clarity (like A8k), but Traillii and Erlkonig have more bass impact than Odin and better bass control than Thummim.


    1. It’s hard to compare to one IEM, Bobby. In general, Trailli is what Thummim should have been, combined with likes of Elysium, Odin, and A18s. Keep in mind, I spent less than a week with Trailli and haven’t heard Erl yet, but it strikes me as the signature where I can’t think of changing anything. Of course, we will be kidding ourselves by calling any IEM “the endgame”, but this one is special for sure.


  1. Why do your “comparison” and “pair up” sections always look almost identical, like it’s the same block of text that you copy-paste with only couple of words changed?


    1. I have a slightly different approach to Comparison and Pair up. From audiophile perspective, the sound is split into sub-bass/bass/lower-mids/upper-mids-vocals/treble and has characteristics of soundstage, imaging, layering, separation, and dynamics. After every review I get a ton of questions from my readers asking how their IEM compares to the one I’m reviewing, will it have more sub-bass or stronger mid-bass impact, does it have thicker/fuller body or will the vocals be brighter or darker or more forward, and if treble is crisper or more extended or sibilant, etc. The same with soundstage, which one sounds wider/deeper, or which one has better separation of sounds. Thus, Comparison section is focused around a short format where I do a very brief comparison of these parameters, so people can decide how different the IEM under the review will sound relative to their IEMs. With Pair Up, again, I’m more into portable setup, and majority of these DAPs slightly vary in output impedance, output power, or just a slight variation in tonality. All these variables not going to change the sound significantly, but some will yield a stronger bass or wider soundstage or brighter vocals. Again, as part of my review format, I take quick notes to capture these slight variations. Perhaps, it’s not exactly a traditional comparison of going into details like I would describe in Sound analysis section, but it’s more of a quick rapid comparison so my readers can determine if IEM I’m reviewing will be an upgrade or a side-grade or just something different relative to what they already have. Hope this explains, and I probably should mention this review approach in About section of my site, so it will be more clear.


    1. Someone mentioned to me they will finally have a universal demo version. So, maybe I will ping them in a near future, too overloaded with work and other reviews in my queue now. Otherwise, I’m not familiar with their sound/tuning and only heard about them being discussed in Nic’s thread on head-fi and nowhere else.


    1. Both are great IEMs, unfortunately Erl is discontinued and sold out. The intent of the updated comparison was because many Erl owners asked me about it. For me personally, if I would to choose one, I would go with Traillii because of a bigger soundstage and less colored mids. Also, Erl silver shells are heavy, and after extended listening period I lose the seal since they start fall out of my ears.


    1. If I would to revisit my personal Top3, Traillii and Odin are still at the top. They are tuned differently and serve a different purpose, Traillii for listening to the music and Odin for analyzing the music/gear when I’m reviewing. I like Erlkonig and A18s (but not custom, rather universal demo version of A18s I have with me now because due to a fit it sounds better to my ears), but they both in a similar tuning category as Traillii where Traillii edges them out per my personal preference. Thus, I would add Ely to my personal Top3 since its mids are truly special, not so much bass, but the mids and with the right cable like Code 51 or Leo II 8wire their EST treble sounds more natural, not as rough as I hear it with stock cable.


  2. Thanks, considering an Ely. I have Traillii already. Odin design does not work for me. Your opinion here really helps. On HeadFi a couple are really ecstatic about the M8/Ely combo. Have a P6 Pro and M8 so if I do get one I can hear for myself. Seems not many have the Traillii but if they did they would probably really like it as well.


  3. Hello and thank you for the review!

    Are you able to provide some comparison of Traillii and VE Phoenix ?

    Thanks again


    1. There are a few differences. In terms of soundstage, Traillii is just a bit wider, but also their imaging is different where Traillii is more holographic with the sound placed further out of your head, while Phoenix brings sound closer to you or you closer to the performer. Bass and lower mids are not too far off, but upper mids/treble differ. Traillii is smother with a more natural “analog” upper frequencies while Phoenix makes it crisper and more revealing, with higher resolution.


  4. Hi!!

    I think that the Traillii are maybe the best and more engaging IEMs i’ve ever tried.
    Recently i think that maybe i could go for the Aroma Jewel, but i don’t know if it’s in the same level of Trailii, if the Aroma Jewel is somewhat near to the Bird, but with better and more DD bass then is a solid choice…
    Please tell me about your comparison between Trailii and Jewel, and wich one is the best for you…and why


    1. I think they share the pedestal, two of the best IEMs I heard 🙂 Many ask me about the bass comparison between The Bird and the Jewel. Traillii bass has more focus on sub-bass rumble and has slower/softer more rounded mid-bass. Jewel has a faster and more textured DD bass punch. Another difference is in mids where Traillii is smoother and more laidback while Jewel is a bit more forward and revealing. Both are great. For me personally, I listen to Jewel more with EDM, Pop, and Rock tracks, while Traillii is better for Vocal, Instrumental, Classical, and Jazz tracks.


      1. Great!! It sound like the next target then…
        Thanks for your guidance man 👍

        Please do a full review of the Aroma Jewel when you can 🙏


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