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UM Amber Pearl: Tiger Thunder

Unique Melody and Cayin team up for a very, very special IEM. The Amber Pearl, building on the Multiverse Mentor, but with bigger bass, a brand new full spectrum BCD, and stunning tiger stripes.


- Huge epic sound

- Amazing full spectrum BCD

- Weighty and powerful presentation

- Fantastic punchy bass

- Pinpoint positioning

- Incredible velvety mids

- Refined, extended and comfortable treble

- Vast stage

- Beautiful shells

- Good stock cable


- Insanely expensive

- Shells are fairly big and heavy

- BCD performance is impacted by fit

- Lots of bass (depending on your tastes)

Greetings dear audio crazies and music lovers everywhere, and welcome to my review of the Unique Melody Amber Pearl IEM! ​

This one certainly garnered some serious attention and created a truckload of hype when it was announced. One reason was that it was only available paired with the Cayin N30LE DAP, a $13,000 combo. Yes, you read that right, 13k, ridiculous. But after CanJam SoCal 2023 everyone was talking about the same thing; the Amber Pearl (AP) IEM was best in show. “They” said it was the best UM has ever done, a knocked-it-out-of-the-park tuning, with an upgraded full spectrum BCD that was next level. I read it over and over. I started to froth at the mouth, and despite my cynical nature of disbelief, deep desire took over my soul. I want to hear it too! How is a guy -who happens to be from SoCal- but now lives in Europe, to hear this already fabled amber stripe-ed creature? I don’t want to buy an extra $5k DAP, I have the LP6 Ti AE and it’s the best in the world, at least for my analog-loving soul. Plus $13k is a rough one to swallow. But somehow I knew that I needed to get the AP, that much was for sure. The allure was powerful enough to occupy my dreams, soundscapes of tiger stripes and bone rattling drums hits were all I could think about. I have a problem, I know, not ready to talk about it.

As a self professed Mason FS lover I know what UM can do with mids. Their use of bone conduction drivers (BCD) bring realism and tactility to the music emanating from these tiny thingies in your ears, roaring it to life in a way that is simply not comparable with other configurations. I remember the first time I heard the Mason FS, after letting my brain burn-in for a bit, that BCD really does transform the experience. You just have to hear it for yourself to understand, it is in fact pretty subtle, but a transformation occurs nonetheless. Despite my love for the blue marble Mason, I did find the stage somewhat small and/or congested for complicated and busy music. It was better with acoustic instruments and voices over electronic stuff, and I longed for some extension in the sub-bass and more open spacious staging. I wanted a true all-rounder, I’ve always preferred having Ione great IEM over a collection. UM seemed to secretly know my (and I’m sure many more people’s) wishes, releasing the new Multiverse Mentor Mentor a few months later. Huge stage, bigger deep bass, more depth and open top end, all with those UM mids. Hooray? I did demo it once and fantasized about its stage and technical abilities, I could hear some brightness or shrillness in the sparkle, and the bass just didn’t quite sit right for me. I know everyone was praising it, but it didn’t quite sit with me as a end-gamer. My search continued on, fast-forward six moths or so, nothing interested me so much. I had the Traillii, and Jewel, but I still felt something was missing. As luck would have it, (but bad for my wallet) MusicTeck began to sell the AP IEM buy itself, sans the DAP, at a measly $8000 price tag. Yes, again you read that right (facepalm). What is happening to the world when companies release flagship IEMs slapped with the price tag of a nice used car? Some scoff, some are insulted for sure, but many addicts don’t even batt an eye and just bring out their wallet… We’re all doomed for sure. I guess I don’t have much to say, I bought it too, whoops! I just had to hear it for myself; a stepped up and refined Mentor, but this time featuring even more gorgeous mids borrowed from the Mason FS, smoother treble and even deeper bass, a new BCD, and a stage you could throw a submarine through. Drooooool…. I couldn’t help myself. It also looks really cool, those tiger stripes!

Does it live up to the hype, does it sound like I hoped and imagined? Yes indeed, it does, but there comes a small caveat. For what it does it well; gorgeous mids and an epic thick and juicy presentation centered around a thunderous low end, it very well may one of the best IEMs in the world. It is addictive like smack, ‘cause the BCD goes to 11 now. The entire frequency range has that titillating percussive quality that also hits harder and more powerfully. Does that mean it’s only good for epic bass central music? Absolutely not. But here the caveat shall be explained. This is an all-rounder-daily driver for sure, and epic music (think EDM, Metal, Prog, Rock, Hip-Hop, Funk) it is staggeringly good. Also, really some of the best vocals I’ve ever heard, it could very well be worth the ridiculous price tag for that alone. For everything else the AP handles great, from jazz to acoustic music, classical, pop and classic rock, et al, but I wouldn’t say it performs “2x better than something in the price rage of half. What I mean is, for “normal flagship” money you can get similar performance for some genres and styles that don’t require or harmonize well with its thick and bassy kind of tuning, BCD aside. But for the things it excels at, or if you prefer more bass and a thicker sound, there is nothing else quite like it, and the price could be justified for those that have the means.

Please don’t go out and sell your kidney for this, it is sublime but no gear is worth that. Unless it’s the LP6 Ti AE, and then maybe.

Now that my lengthy intro is over, and before I get into the fever details let me quickly do my usual testing gear rundown and disclaimer in favor of transparency:

-I purchased the AP myself, though I did receive a discount from MusicTeck in exchange for a review. As always, there was no pressure or requirements of me to provide a positive review in any way, I was simply asked to share my views, experiences and thoughts with the community. I did perform around 75+ hours burn-in before doing any critical listening and note taking. After my initial critical A/B stage I listened to music as I normally would for several weeks, to get a feel for the AP alone. I then came back to AB’ing and cable rolling before sitting down to write this review. I was listening to it 99% of the tine while writing, which I find helps me to center my thoughts and solidify my impressions.

-To be clear, I review because I love doing so, it’s a great source of joy for me. I don’t do this for work, I spend an enormous amount of time on these. I take it very seriously, as I know people rely on reviews before they shell out enormous amount of cash, just like I do myself. For that reason I only review things that interest me, things I would maybe buy for myself. If you’ve read any of my previous reviews you will know that I usually choose very expensive gear. This here is a very expensive IEM, clocking in at the aforementioned $8000, which is simple insanity. The IEMs I will compare them to are stupid expensive too, and calling them “cheaper” is another kind of crazy. The pricing of gear is totally nuts and we’re headed for Armageddon if this continues (I think I’ve copy pasted this in a few reviews now). Please try to keep in mind that some people in this world have the money for these kinds of toys, I will try to focus my review on the sonic aspects so we can take a look at these here Summit-fi showstoppers without their cash melting contexts. If you are insulted or morally wronged by these price tags just stop reading and find something else to do, I don’t blame you at all. It costs a literal arm and leg, moving on.

-I used a very varied playlist of testing tracks to form my initial thoughts, and then spent several weeks simply listening to whatever inspired me like I normally would. I love all kinds of music, and to form an honest opinion for any piece of gear I think it absolutely necessary to test with lots of different kinds of music. If you’re taking a reviewer’s word about a piece of gear you want to spend your hard earned cash on, in my opinion you absolutely should take how their musical tastes match or differ from your own. A few excepts from my latest listening roster:

Jazz: Snarky Puppy, GoGo Penguin, Coltrane, Miles Davis, Charlie Hunter, Avishai Cohen, Kandace Springs, Chris Potter, John Scofield, Kurt Rosenwinkel, Esperanza Spalding, Gregory Porter, Julian Lage, Funky Knuckles, Ghost Note, Aaron Parks.

Rock: Led Zeppelin, Jeff Beck, Hendrix, Pink Floyd, Dire Straits, Talking Heads, Rage Against The Machine, Eric Johnson, Michael Landau, Them Crooked Vultures, Tom Petty, Jackson Brown, Jethro Tull.

Modern Music: Jordan Rakei, Tom Misch, Lianne La Havas, Asgeir, Fat Freddy’s Drop, Glass Animals, Jacob Collier, Moonchild, Robert Glasper, Hiatus Coyote.

Electronic: Om Unit, Emancipator, Kryptic Minds, Bonobo, FKJ, Djrum, Synkro

Heavy Music: Animals as Leaders, Tool, Gojira, Polyphia, TesseracT, Meshuggah, Hacktivist, Trivium, Sevendust, Periphery, Sepultura, Intervals, Plini, Polyphia.

As source I used my LP6 Ti AE and Sony WM1ZM2. For comparisons I did in-depth, intense AB comparisons with several IEMs I have at my disposal at this time. Some are mine and I know well, others are here for review/borrowed. They include: Oriolus Traillii, Aroma Jewel, Rhapsodio Supreme V3, and Mason FS.

Without further ado, let’s get into it!


As stated above, the AP is Unique Melody’s newest offering, a kilobuck flagship with everything and the kitchen sink thrown in. Their latest tech, an updated full range BCD that UM claims to enhance the entire spectrum of human hearing. I can attest that it is indeed their best BCD to date. UM has decided to give us a beast of an IEM with 30 combined drivers, 15 per side. 4x BA for bass, 2x BA for mids, 2x BA for upper mids, 4x BA for treble, while a pair of EST take care of the ultra highs and the BCD makes 15. For a neat diagram of the innards and some additional information you can check out the MusicTeck website since I cannot find any information at all on the UM website itself. I suppose it’s because the AP wasn’t originally planned to be sold alone, so I’ll skimp on most of the technical details and can read what’s available here.

The IEMs themselves are very pretty, with a warm orange glow accented with stripes of blonde wood grain in varying shapes and patterns, as each IEM is totally unique. If you look closely there are even some sparkles in there, accenting the bright orange sheen. UM uses stabilized Cholla wood, essentially a cactus wood mixed with resin to achieve some of them most beautiful shells on the market today. These are not understated, quiet or minimalistic looking, they are attention grabbing for sure. But I was pleasantly surprised they don’t look gaudy, or like cheap balls of orangey snot either. They’re rather beautiful, really.

To be clear right off, these are hefty IEMs. They are big and deep, though not super heavy since the shells are very light material. The body of the IEM is fairly large, the nozzle is shorter but very similar to any other UM IEMs I’ve tried. There is a replaceable filter at the end of the nozzle which is a great inclusion, with a notched lip so tips really stay on. They’re even hard to get off sometimes. Contrary to the Mason FS the faceplates are concave, I would imagine this is to fit in the bigger BDC (Le Jardin has the same). Comparing to Mason FS the depth of the shell is for sure bigger, and in ear they stick out more than any other UM IEMs I have tried. I have relatively small ears so that’s not saying so much, but just beware that they are pretty deep and relatively cumbersome for average ears. Not prohibitively so, but not tiny either. I tried out every tip I own, from Azla to Symbio, UM, Aroma, Acoustune, Spin Fit, foams, random otehrs, and in the end the best by far was the new Baroque tips made by Eletech. If you haven’t had a chance to check these out yet please do, they are nothing short of a revelation! With size S I was able to get the AP deeper into my ear than with other tips, and thus had a better BCD experience as well as the IEM not sitting outside of my ears as much. I also really enjoyed the stock UM silicone tips, there great, for those I used size M. As a happy surprise the 2 pin sockets are super snug which is a great upgrade from the usual UM loosey-goosey sockets I’m sure many of us are all too aware of. Only time will tell how well they hold up, but I am optimistic so far.

I think for most people these will fit just fine, just know that they do stick out of your ears a bit with average ears. Remember that the BCD requires actual contact to work, so the more of your ear is touching, the better the effect will be. At this time it is not clear if the AP will be available to the public in a CIEM form, I have inquired and am waiting for confirmation back. As normal with CIEM you would probably experience a slight bump in bass quantity, but also the BCD expressiveness and tactility would be further improved. Sounds good to me!

The AP requires more power than one would think, the EST top end and the BCD for sure are power hungry. I found that it sounded quite good from just about any source, but scales incredibly well. With a laptop and adapter/dongle I was easily able to get good volume and engagement, Sony M2 was fabulous, AE was another level of grand and epic. When I first got my Mason FS years ago I remember being told they only sounded their best from L&P R2R DAPs, and then I would have agreed. Now I think they have a very special sound with L&P, one that I personally love, but they sound amazing with DS DAPs as well. Perhaps its something in the impedance or tuning that UM has changed, but I find them far more universal to drive now, which is good news for everyone.


For anyone familiar with my reviews I am usually very uninterested in the unboxing experience. I do care about what comes in the box, but no so much the box itself. My reviews of cables are a bit different, as no-one I know uses the box their cable came in for storage, unless it’s a nice puck case or similar, and thusly I largely ignore the boxes and superfluous chotchkies that come inside. The same thing wouldn’t be said for IEMs, the case that comes with Summit IEM’s is usually quite nice and serves the divine purpose of storing the IEMs -with cable attached- for all the time that they are not in your ears and performing their sonic duties. If, for your hard earned $8k you’re expecting fanciness and gold plated trinkets inside you’re in for a harsh reality check. In keeping with UM’s usual basic setup, the AP comes in the typical branded blue box which flips open to show the stitched leather case holding the good stuff inside. There is also a slide drawer that houses all the accessories like tips, cable strap, clip, etc. You get two types of tips, one being the stock UM tips with the blue stem, as well as some Azlas. Open the leather case up top and out comes the APs, each nestled in a blue mesh bag for safety. The leather case is pretty basic, unpadded, blue stitched with gold zipper, with partitions that hold the goods in place well enough and can be used for daily storage if needed. Honestly, I don’t care much, but for this kind of money the packaging, and case, is rather disappointing, or lackluster. Even with its infamous cardboard box, the Traillii came with a very nice VanNuys leather case that hold my Bird to this day. I would have expected more, even if I personally wouldn’t have used it.

The included stock cable is a nice 4 wire PW cable in deep blue cloth sleeving, with the traditional UM branded connectors in teal. I wish they would just use black hardware, can’t UM just add their logo without changing the color? That’s wishful thinking I guess, I just personally prefer black. For those familiar, the AP cable looks a lot like First Times or Mason’s Deep of Universe and is aptly named Amber Pearl, since Peter Wong couldn’t come up with another bizarrely named, grammatically incorrect moniker. (I LOVE PW cables, but the names are always so funny). I can’t seem to find much information about the AP cable online, other than it is “newly designed” by PW Audio and features their high quality 6N OCC copper. It’s called a shielded cable, but this isn’t the traditional thick and heavy shielded cables like Orpheus, FTS, or Meet Agains. It’s very flexible and light, and like all PW Cables sounds great. For those who know, Orpheus, FTS and MAS all feature a higher level of copper, and the added shielding does affect the sound in many positive ways. You can check any of my reviews for more information. I’ll dive deeper into it later on in the review, but it’s a shame UM didn’t include a more expensive cable for this insane asking price. That being said, the stock cable really does fit the tuning of the AP well, and while you can certainly cable roll with upgrades, the stock cable is perfectly suited. I’ll get more into comparisons later, but rest assured you’re getting a good cable with AP, if not their TOTL Shielding versions.


So how does the AP sound? They are amazing. Fantastic. Unexpected too. When I first got them in my ears I was a little bit surprised because they were super thick and powerful sounding. I had expected a full sound sure, but one more mid focused since having owned the Mason FS I had believed that was the UM house sound. Now not to say that the AP doesn’t have great mids, it most certainly does, but there is a feature on the lower mids and bass that totally blew my mind. They are so HUGE and powerful sounding! Drums and bass, kicks and thumps, waves of synth pads rumble my guts and swirl around my head like some sort of frequency storm. I was simply not ready for the turbo onslaught I was greeted with upon first listen. The Thunder tiger. The velvet hammer; a slightly warm but undeniably resolving lush tonality with a bottom end to match, I was pretty knocked over. The AP is a natural and fairly balanced tuning, with the extra low kick pushing it perhaps more towards a L leaning W, or a shallow V with the right cable and tips. This is no bass canon, but it’s not shy in the least either.

The mids are positioned forward enough not to feel distant, and quantity wise it’s more like a W than V. Please do keep in mind that my DAPs are both heavily mid forward, especially the LP6 AE, so that is certainly affecting the balance of how I am hearing it. Based on how the AP graphs your experience may be more a V than mine.

The bass might be featured, but it is also of great quality and power. It reaches deep, hits hard and has a nice extra heft in the upper bass to give things a serious boost of energy and drive. Add that to my AE’s powerful midbass kick and you have an addictive presentation for rock, electronic, prog or anything that has a big low end and emphasized lower mids. Ballsy and grunt worthy for sure. Now, you might ask why I’m speaking at length about the bass when this is clearly a balanced Unique Melody ultra flagship set. Does this mean the mids aren’t the centerpiece? Not at all, the bass is just what I heard first and these early surprises are entirely based on my expectations and nothing more. The mids are fabulous, emotional and wonderfully velvet to the touch. Very detailed, perhaps one could even say exquisitely detailed, while never once going into the territory of harsh, crisp, or analytical at all. Vocals are sublime, top 3 of all time for me. There is a sweetness that’s hard to describe, especially when mated to the solid prominent low end. Mids and vocals are most certainly important, featured even. Just built on a very hefty and solid lower end that can sometimes overwhelm their presence for me, track and cable dependent. This is a balanced set, bass featured, with great mids and treble, that’s how I would describe it. The BCD adds a great sense of realism and physical qualities, adding in a extra dose of note weight and attack while not being hot or flashy. Same goes for the treble. It’s very nicely extended, detailed and full from the BCD’s active presence here as well. It’s almost weird to hear treble notes with so much body on them. Even the tiniest details way up top, over your head and floating in space, they have this physical attitude and percussive quality that is rather mind-blowing. You can feel them. Even the tiny EST producing flakes of gold and light you can feel like they reach out and caress your face. I know I keep saying percussive, but from a musician’s (guitarist+studio engineer) background such as the one I have, this is the only way I can describe it. Notes that you feel, and hear. Notes that create a sense that you’re in the room. You can feel the air from the horn, the waves from the snare hit as it physically affects the space around you. This is fit dependent of course, the better the fit the more the sense of BCD’s impact, but it’s certainly there for the taking. Updated from the Mason FS is the inclusion that the BCD is now full range, meaning you hear it in the sub bass too. It’s actually quite wild, the bass is a totally different animal with a full range BCD. Thump and pump, rumble and shake. Pretty cool.

The stage is large, expansive and spherical. It’s not the largest stage I have ever heard, something like the Traillii is indeed wider and taller. But the AP’s stage fits to the style of the tuning, and feels gigantic with the way that it presents drums, guitars, reverb and space. There is a lot of space up top, no doubt aided by the AP’s inclusion of ESTs for the upper treble frequencies. It seems this is the way of the future, all that air and space seems hard to create in such and natural and effortless way without their use. The main takeaway here is that the AP is a wild animal, with a sensitive side. AP does soft and gentle, with that low-end presence adding a blanket under your music for smooth rolling rumbles. When the track calls for it then it will be bombastic, physical and demanding of your attention. A BCD isn’t like you feel smacked in the face, its a very subtle and gentle addition to the sonic spectrum that adds realism, authenticity and percussive qualities to your music resulting in a very 3D experience unlike anything else. Another thing to mention, is positioning or placement. This means the listener’s ability to pinpoint where in the stage a certain sound, instrument or aspect is emanating from. Like being able to see in the sonic stage and map out where everything is. AP has the best positioning of any IEM I have heard, hands down. This is largely based on the new full spectrum BCD, so every tiny bit of information can be seen, heard and given a precise location in your head. All this contributes to the sense of reality, realism, and just bad-ass-ery that is the AP.


AP does bass like it should be. This is GREAT bass. It is in fact about as good a BA bass set as you will ever hear. The only other I have heard that is same/better was the Storm, based on memory. AP is punchy, full of texture and nice guttural rumbles. Going very deep into sub-bass territory, rumbling your brain like crazy, but the feature for me here is the midbass. It has a lot of slam and punch. It’s tight, clear and powerful. It’s bombastic without bleeding into the other frequencies. In the mid-bass area it sounds about as good as a real DD, the sense of texture and grip is really thrilling. In the sub bass regions I do notice the lack of a DD somewhat, there’s not faking that sense of air a real D-driver gives off, that’s just physics. There is a bit of that plasticky sound down low in the lowest regions. (There one exception, I find the sub bass of Traillii to be very DD like, and I feel like I do feel “air” being pushed when the bass hits really low. Traillii Midbass is not as guttural, and lacks the bump and pump of the AP) That being said, this is a set with truly fantastic bass. I would say it’s more like a vintage tube amp bass vs an ultra modern and Hi-Fi bass. There is a sense of real grit and grease when called for, and I mean this in a good way. It’s got spank, and that’s not something you can EQ in. Add in the BCD and it’s an experience you won’t soon forget, or get anywhere else. The way the bass kicks you, pun intended, is very surprising and amazingly engaging. You feel the bass in your chest and guts simultaneously. Damn addictive!

If I have one critique of the AP’s tuning is that the bass shelf - TO ME - seems a little too much, and takes away from what would otherwise be a perfectly balanced set. I know I’m in the minority here, some friends have told me they EQ the bass up on their APs (wowzers), but for me as more of a reference listener these were super fun, but ultimately the bass did overshadow the greatness of the near perfect tuning on occasions. This is also affected by my DAPs of choice, both featuring a slight midbass bump themselves, but I found myself EQing 125hz down about 1.5db, and then it was nicely balanced for some less bass heavy styles of music. When I first got the AP it was REALLY bassy, but after about 80+hrs to has fallen more into line, and feels less bloomy. I imagine that after another 100hrs this will be even more improved, though I don’t imagine the signature to vary much more, that extra bass is there to stay, just improved.

It’s not that it was ever bloated, bass is very tight and punchy, but I found that the lower mids and upper bass just overtook my attention when the music didn’t call for that kind of thing. For EDM, Prog and heavy rock I left the EQ alone and just let the AP blow my mind. I mention all this not because heavy bass is evil, I love a good slam, but I think that UM might have reeled this back a bit. It would be perfectly balanced with just a tiny bit less. As a canon set it’s pretty neutral, but for a W all rounder it’s a tad too lifted if such a thing can be said. This is ONLY my opinion, and I know I’m in the minority. Bring out your pitchforks folks, this guy is saying too much bass. I will go on record here, I prefer a linear tuning, great badass bass, but it can’t lean on other frequencies - if the music doesn’t call for it.


I have heard a lot of IEM’s with great bass, but, I am not a major bass head as you’ve just read. Contrasting to many here I found the Jewel’s quantity of bass to be just right for me, at least in CIEM form. Xe6 was a no go, arguably amazing, but not ultimately enjoyable for me. Too warm and way too much midbass (in my limited time with it.) Traillii has a nice amount of bass, as does Mason FS, or Elysian X. I enjoyed Fir’s offerings, but even with the red module I was overblown. Now you know where I am coming from, so you can adjust your feelings about my bass feelings in order to have a clear idea of AP’s bass feelings. Remember, this is about buying an IEM, committing to it, not how much I enjoyed it for 15 minutes on my buddy’s couch.

- Traillii - Deeper reaching sub-bass with the less midbass. More pushed air down under, but far less grunt, punch and texture in the upper bass. The Bird slams well but its more relaxed, AP is tighter, flashier, and calls far more attention to itself. AP has about 2-3db more quantity at least. Bird wins for DD style sub-bass, AP for punch, texture and speed.

- Jewel - Real DD sound, very nicely textured and tight. Fast for a DD. AP is bigger, bolder, punchier and with noticeably more presence and weight. Reaches deeper with a more noticeable sub bass rumble. Jewel wins for the DD texture and sub-bass air, AP wins for everything else.

- Mason FS - Fast midbass featured BA set. Much less sub bass, less overall quantity. AP takes everything about FS and just improves it in every direction. The only thing I prefer from FS - on occasion - is the quantity, which is nicely balanced over the AP’s slight overabundance.

- Supreme V3 - For a single MST DD driver the amount of dynamics and detail is quite staggering. The bass is very clear, supremely detailed and well extended. Best texture of all of them, really great quality. But, the quantity will not be enough for most people, myself included. It will leave most wanting for more, wishing for more. It has an equal presentation of sub and mid bass which does in fact match the V3s extremely airy and spacious sound.

DEEPEST > Trailli - AP/SV3 - Jewel - FS

TEXTURED > SV3 - Jewel/AP - Traillii - FS

PUNCHIEST > AP - FS - Jewel/Traillii - SV3

NEUTRAL > FS/Jewel - Traillii - AP - SV3

QUANTITY > AP - Traillii - FS - Jewel - SV3


As I have mentioned on any of a million occasions, I am a big fan of mids. They are the cat’s meow, or their pajamas, I can’t remember the phrase right now. The show stops with the mids for me, and they need to be accurate, detailed, and natural sounding without too much “stuff” going on to alter their correctness. That doesn’t mean they need to be boring or dry, they can be lush and wondrous, velvety and smooth or crazy detailed and more energetic, I can get down with all of that. Don’t hate on the reference guy! AP has some of the best mids I have ever heard, really. They are fabulous. Move you to tears vocals. Move your soul, really. These are UM tuned mids for sure, and I am hearing a great deal of Mason FS’s influences here. These are weighty and powerful mids, continuing up from the bass’s impact and heft. They are more velvet than edgy, more romantic than crisp. They are really fantastic, with just a little bit of extra bite around 8k to give some clarity without being sibilant in any way shape or form. Guitars crunch, guitars pluck and pump. Synths are especially satisfying, they grind in a way that I have never heard in another set. The lower mids are very thick, they thin out a bit going up but not much. This is a weighty mid section placed forward which makes them more vivid, while also upping the engagement factor quite a bit. There is lots of space between the layers, transients are clean but more on the relaxed side vs technically or analytically. That’s part of what makes AP so special, it’s musical, fun, exciting and energetic while never leaving you wanting on the details and technicals. This is a great balance, and I think many other companies could learn this for their flagships. UM has nailed this one out of the park for the mids - the perfect balance of engaging, fun and technical powers I have ever heard in an IEM. Very very detailed, but I don’t hear anything out of place, nothing accentuated overly to give a sense of extra bite, space, or resolution. They are just, for lack of a better word- perfect. Bravo!

The BCD adds the most sense of realism in the mids, while the bass is kicking and jumping, the mids is where the most “real” percussive instruments live. Bass kicks are great, but what about hearing the click of the pad beater on the actual drumhead clear as day. Then what about feeling it too? Guitars where you can feel the strings being plucked, strummed, or even hammered on. Drums are dope…. So physical and guttural. Thwacks and clicks, the lip smacking of your favorite vocalist, all presented in a way that I have personally never heard before. I think words struggle to pass on enough information when it comes to the BCD, it just adds a sense of realism that I just can’t describe. Suffice to say, if you don’t know what I am talking about, try out the AP, and then try anything else immediately afterwards. You’ll hear what’s missing.


Not a surprise to anyone I have chosen sets here to compare that feature amazing mids. Mids all done in different ways, so in this section I must tread carefully here with words like better, more this or that, etc as those imply a sense of perfection that carries over style, tuning, and preferences. I’ll do my best.

- Traillii - Arguably some of the best mids ever. Emotive, spacious, effortless and micro-detailed. Mids are placed further back and away from you giving some of the best stage space of any IEM ever made. The technicals are top notch without ever getting into analytical territory. AP is more thick and forward, Traillii is lighter and thinner, and spaced further away. Traillii has a small dip in the 4-6 kHz region, AP has a slight glimmer in the 6-8Khz region, but both sound very natural and more relaxed than anything. Trailli spread the mids waaaaay out to the side and above creating space but losing intimacy or engagement sometimes. AP mids are closer and more engaging, but they do miss out on the space the Bird can give. Bird is a bit relaxed AP is a bit more energetic. Sometimes I preferred AP for some heavier music, Bird for a different track. Vocals are amazing on both. Hard to pick a winner, I went back and forth for hours/days and couldn’t decide.

- Jewel - Great technical mids, a bit thinner and cool/analytical but only when compared to Bird and AP. More mid forward, with a noticeable bump in the 4-5khz region that can make some female vocals a tad shouty, or some instruments having extra bite. Subtle, well done, but noticeable. AP and Traillii are sweeter, more velvet. Jewel is more accurate perhaps, less fun, or at the very least more “reference” which is why it stood with me as a daily driver for so long. Large spherical stage here, less wide than Bird, similar to AP, but AP goes wider and much taller. Here’s a spot where a company went for a little more detail and less emotion, though I personally find the Jewel’s mids fabulous for my vast array of musical tastes. Another great all rounder.

- Mason FS - Here is a really tough call, AP and FS mids share a lot of similar vibes. AP is thicker and juicier, FS is still thick but a bit more clean and less moist, which is a weird way to describe an IEM but I stagger trying to find another word to use. Vocals have this almost wet juicy feeling, while FS is a tad more flat. AP has a bit more resolution only because it’s newer, but that doesn’t necessarily mean the mids are better. Only when comparing directly to each other are these subtleties clear, as compared to other IEMs these are at the very least extremely similar. AP takes the cake for emotive and fun, FS might be a tad more correct. AP stretches the mids out more, FS is a tad more intimate. They are both UM tuned, with the same sense of realism and love. There is something about UM mids that you either love desperately, or they’re just fine - if you’re the former than you’ll love either one of these. (FS mids are hard to beat for a used price tag around $2500 btw.)

- Supreme V3 - This is a totally different beast. The V3 has more details than any of these IEMs, and somehow still remains musical and fairly natural. The sense of space is also different, like a giant oval all around you, a bit like the Thummin, very unique. The level of microdetails are off the chain, the way little things pop in and out of your sonic spectrum, it’s wow. Vocals are very forward, sometimes almost feeling like the singer would actually touch my nose. Mids are thinner and less hefty than the others, especially the AP. Going back and forth between these two polar opposites was like a fancy quill pen made of sparkles and a sledgehammer! V3 has a noticeable bump in the 8-9Khz region that adds a great sense of bite and energy, but I found it somewhat tiring, and in the worst cases, slightly sibilant. If you listen to modern pop and vocals music, and you like bleeding edge details while remaining effortless the V3 is unchallenged. But I would say for “western” ears it could be a bit too intense, thin, or energetic for some music and tastes. Stage for mids is scary big, I almost lose where I am in the space it’s so spaced out. Not in a bad way at all, I’ve never quite heard a midrange like this.

DETAILED > SV3 - Traillii/AP/Jewel/FS

WEIGHTED > AP - FS - Jewel/Traillii - SV3

TEXTURED > SV3 - AP/Traillii/FS/Jewel

ACCURATE > FS/Jewel - Traillii/AP - SV3

SPACIOUS > SV3/Traillii - AP/FS/Jewel

ENERGETIC > SV3 - AP - Jewel - FS/Traillii

EMOTIONAL > AP/Traillii - FS - Jewel - SV3


The treble on AP I found to be fantastic, airy with plenty of detail without ever bordering on a sense of sharpness, crispness or any other ‘ness that could cause discomfort or fatigue over long sessions. This is sweet stuff. It’s very resolving but erring on the side of lush over a sense of technicals, even thought it is indeed very technical. There is plenty of sparkle, but extremely well contained. Once again the UM team have hit it out of the park with the way they were able to give it so much resolving power, tons of air and space, all without sacrificing the musicality and ease of listening. I hear cymbals splash and crash without a hint of glare, without losing out on the energetic attack, or feeling of presence and attack. My usual treble air test track (Jordan Rakei - Clouds) gives a great sense of the vast space, and hearing the airy breathing all around me with the BCD feels like I might just have to wipe off my shoulders and ears when it’s over. The vertical stage is quite good here, lots of air without getting overly out of head and ruining the realistic experience. The BCD does play large role here as well, adding weight, percussive qualities and realism to the top end. I hear it all the way up to 12-14Khz, still adding thickness to even the tiniest speckles of golden dust and featherlike air. Fantastic! There is a slight bump up around 8kHz to add some extra energy and bite, but it’s very light and feels at home with the rest of the tuning. There is also a roll up around 16-18Khz but I have to admit that my 40 year old ears no longer hear well quite that high, or at least not at full volume. If you’ve got dog ears and can hear that, Kudos to you, I’m jealous. I’m sure an extra does of slight brilliance up top would be lovely, and if you’re a young one that can still hear to 20kHz you’ve experienced it differently than I.

I think there are taller and more spacious top ends, that award would go to Elysian, or even Traillii as being the “bigger” “taller” or “extended” by a small bit. But what the AP does so well is keep all the dimensions equal and realistic, increasing the ever present engagement factor. Widest, tallest, or biggest aren’t always something to aspire to, unless it’s matched well. That’s not to say the stage of AP is small, not in the slightest. This is a vast and engulfing stage, one of the bigger ones for sure. It’s not as spaced out as Traillii, but the positioning is better, and it’s clearer where in the stage the sound is emanating from. The AP treble is very smooth and easy to listen to for hours on end. All the hotness and spice of the Mentor has been replaced with effortless air and sparkle that just puts a smile on my face where otherwise my infamous treble sensitive would bear its ugly head and leave me running for the door. One of the best trebles I have heard, it is not as effortless and light as Traillii, or insanely detailed like the SV3, but fabulous for sure. Add in the BCD weight, and the general theme of epic, big, huge and epic again rears it’s head once more. This is one big thick sound, even the top end. The Roaring Tiger, Velvet Reverb strikes again!


- Traillii - The Bird is lighter on its feet, and could on some tracks have more sparkle energy resulting in perhaps sounding “brighter” though I hesitate to even use the word. Traillii has a dip in the lower treble making it a bit smoother, AP does not. But somehow I hear the Bird with more sparkle than AP, which sounds more even, all the way up past infinity. Bird treble is very light and airy, like it’s floating in space, very EST like. The Traillii vertical stage is larger and higher here, so the stage feels more open and spacious. AP has more weight, given from the full range BCD doing its magic up top too. Both are fabulous, but I may prefer Trail simply for the fact of that endless space up top, where AP sounds more intimate in comparison, though it is very big and airy too.

- Jewel - For all that I love about the Jewel, its treble is not its attribute who’s love is shared by the community. Famously rolled off and slightly overly relaxed, that’s how I would put it. The spike at 4kHz gives it nice bite and clarity, but almost immediately afterwards it is very airy, and spacious, but loads of sparkle it does not give. I never minded it at all, I found it very enjoyable, but comparing to these treble wizards here I think the Jewel stays more ordinary than exemplary. AP is airier, more open and sparkly while retaining clarity and naturalness. BCD makes it weightier too.

- Mason FS - Another close tuning contender here, though with the EST and full range BCD the AP leaves the FS holding its hat a bit. FS has wonderful treble, but the AP is just better. Similar type, similar tuning, just more open, more airy, more weight too since the FS’ BCD does taper off before the high end. The inclusion of the AP’s EST top end gives it a more effortless style of air and space. More float, even with the added body.

- Supreme V3 - Here is another instance of complete opposite design styles, where one will be either blow you away or polarize you. While the AP has a very generally tuned and perfectly enjoyable high end that would be hard pressed to have haters, the SV3 pushes the limits a bit more. SV3 is indeed more of everything, and if you’re into that kind of tuning there is nothing like it. It is VAST…. Wow. Stage is almost not even the right word for it, just space. The level of detail here is totally mind-melting, it’s the most resolving top end I have ever heard by a large margin. BUT, and this is a fairly big but, there is a lot of energy here too. In my uses I had to EQ down the area around 8kHz by at least 2db for it to be comfortable for longer sessions. It’s not sibilant, it’s not bright per se, it’s simply energetic, or vivid, or cheerfully exuberant. Sharp yes, hot no. Clean and clear? The cleanest and clearest you’ve heard. Vocal reverbs are nuts. Electric guitars/splashes and harder hits are bit too much sometimes. Electronic and modern mastered music will make you reconsider your own hearing, there is so much going on you’ve never heard before. But not for the faint of heart, it’s A LOT. Think about a trumpet or saxophone, that extra edge of metallic energy and brilliance around every note, that’s what I’m talking about here.

QUANTITY > SV3 - Traillii/AP - FS - Jewel

QUALITY > Traillii/AP - SV3 - FS - Jewel

EXTENSION > SV3 - Traillii - AP - FS - Jewel

WEIGHT > AP - Jewel/FS - Traillii - SV3

DETAILS > SV3 - Traillii/AP - Jewel/FS

NATURAL > Traillii/AP/FS - Jewel - SV3


This section is copy pasted from a cable review I did, I think it sums it up quite well for my personal feelings.

As always, stage size is hard to quantify and explain. Let’s look at the root of the term “soundstage” for a moment. To me we’re talking about the space around you- in front of you, above and behind you, to the sides- where music is emanating from one central area and the surrounding environment is portraying, affecting, or mirroring this sound into a 3D environmental experience for your ears. There is clearly a stage, with performers, and you the listener are positioned somewhere in the space. You may be in front row center, or “rows” back, like a concert or 2 Channel speakers at home. You could be placed inside the band, like they’re sitting next to you, or even all around you. I have been privy to hear some drool-worthy, insanely expensive 2 channel systems, and let me tell you, they all sound like you’re INSIDE the studio with the band. I’ve also clocked more than my fair share of live concerts, and in that live scenario the band is clearly in front of you, and the music comes from one huge source in that direction. Some may prefer sitting in the middle of a crowd at a festival, moshing or swaying back and forth to the beat, subs shaking your chest with giant vocals floating above your head and a light show emblazoning the sky. Or you’re in a smaller club, smaller system, but the band feels like you can reach out and touch them, emotions flying to your sheer proximity as you can brave their cigarette smoke. Or, like a Snarky Puppy live album, the crowd is literally inside the space, fist bumping along to the crazy inspired jams as one tries desperately not to touch all their amazing gear. So which is bigger? Which is better? Thankfully we don’t have to choose, everyone can enjoy whichever makes them happy, hooray for choices!

As I said earlier, AP has a grand stage. It’s quite even in all directions, though I hear a bit more height and depth vs width. It’s very natural, giving this sense of epic rock anthem soundscapes, without pulling you too much out of head and ruining the sense of reality. This is stadium big, a huge sound, but not disappearing into the next state as some aviary units do. If I had to try and describe the stages in terms of physical dimensions I would say this:

AP - A big 3D oval, with sounds emanating from all around you, especially vertically.

Traillii - An oval, hugely circular, but with the midrange stretching out at the widest edges as far as one can see.

Jewel - a lovely circular stage in all directions, with less height.

Mason FS - A narrower oval, with the high and low end stretching a bit further but keeping the mids more intimate.

SV3 - A very holographic stage, with more depth than any other IEM I have heard. Truly all around you.

SIZE > SV3 - Traillii - AP - FS - Jewel

WIDTH> SV3/Traillii - AP - Jewel - FS

HEIGHT > Traillii/SV3 - AP - FS - Jewel

DEPTH > SV3 - Traillii/AP - Jewel/FS

HOLOGRAPHY > SV3 - Traillii/AP - Jewel/FS

NATURAL > AP/FS - Traillii - Jewel - SV3

EMOTIVE > AP/Traillii - SV3/FS - Jewel


It’s become the norm that ultra flagship IEMs finally come with good cables, decent cables. Are they fitting to their price tags? Not really. However there is at least something we can celebrate. As the prices of IEMs keep going up star-ward, the inclusion of something fancy enough not to rip off immediately and replaced in vicious fashion is great news for all of us. All of the IEMs in this group come with good cables, (except Jewel) but considering the price of some of these, it could be said with strong conviction that the manufacturers should have included the very best cables they could find, instead of making us all feel baited and switched when the time comes to shell out cash. The AP comes with the aptly names Amber Pearl cable, and it is a fine cable. It is very similar to the Deep of Universe cable that came with Mentor, though in this case it is pure copper instead of SPC. It also reminds me very much of First Times, especially the weight and color. It does have the somewhat uglier UM hardware which I disapprove of, and I am anxiously awaiting an apology from UM that most certainly will never come as they couldn’t care less what I think.

As stated in my prologue the AP cable is perfectly matched to the IEM, sounds great, and is of high enough quality and resolving powers that the average user for such an IEM could be happy “forever”. UM gave us that much at least, it sounds great. That being said, said manufacturer released another kilobuck IEM last year, and that one has a fancy $3k Meet Agains Shielding cable while the AP has a lesser one. They could say how this cable is precisely matched etc, but I feel it’s a bit of a gut punch not to include a true TOTL cable for this kind of stupid expense. Or Traillii for that matter, $6k and the cable is a fairly standard 4 wire PW 1960s (ish), similar to AP. A great cable sure, and better than some brands give out with their TOTLs, but certainly not the flagship cable available. At the time Traillii’s high end cable made waves, but I think now we all expect a bit more, as prices have soared, so have our expectations to boot. Mason FS came with the PW Attila shielding, but that IEM costs half so the quality to price ratio is fair enough. The SV3 comes with a good RSD 2 wire cable, similar price range as the others. But for this $6.3k flagship RSD recommends their Copper Fantasies -which is a stunning cable- but only for a measly $3k more. And last but not least, the Jewel. This fancy $5.4k IEM comes with a stock cable that looks like they bought it off AliExpress for $3. I’d sooner cut it off with scissors than let that disgrace ever touch my IEMs. Bwah, that is really the worst of them all.

As I said, we have something to celebrate, stock cables are getting better! But for these prices it should be the best.

Rant over. Sorry.

The following is synergy with each of the fancy cables I currently have at my disposal compared to the stock Amber Pearl: Orpheus, 50s Shielding, Rhapsodio Copper Fantasies, and Shirogane.

AP - The stock cable provides a very nice balanced sound, and despite my earlier rant about price, is a fine (meaning: with great class and style) pairing. It holds the AP’s tuning well, providing the huge bass, nice full mids and balanced airy and spacious treble. It has great resolution, tactile energy and very comfortable weight and ergo.

-Swapping it out for Orpheus was met with more resolution, wider stage and more microdetails, but a bit too much midbass. It got overkill for me there, for the sheer amount of bass, but also for the excessively positioned mid bass bump. Orpheus mid were pushed a bit further out, which was a welcome stage increase, but it seemed also to shorten the vertical dynamics and remove some of the air and extension. Orphy is also quite warm, and the mix with AP’s warmth and LP6 Ti AE or Sony WM1ZM2’s warmth was too much. Amazing cable, but not the best synergy with AP, unless paired with a more neutral DAP.

-50s shielding was great, a bit more reference and clean. Great strong bass, adding in a bit more quantity but upping the quality over stock. Rolling off the upper treble just a bit, but a very good pairing and not feeling closed in above like the Orpheus does. 50s has a unique ability to amplify an IEM’s natural vibes, adding just a tiny dose of copper magic to the mix. Detail and resolution are great, as is the pitch black background. Recommended.

-Shirogane took away some of the extra bass of Orphy, which was welcome for me, and added a healthy dose of upper air and stage height. Vs stock the bass is about the same quantity, but deepened, made more taught and textured. Mids are more forward while being more spacious and airy. This brings the AP’s slight V into full blown W territory. It did however smooth out the mid edges a bit, so heavier style of music weren’t as bombastic or energetic, but electronic was great with deeper bass. Vocal tracks, just wow. Treble is more extended, more open, and slightly more featured. I find the Shiro to add a sense of Electrostatic full size headphone-ness to the vibe, there’s something about it that makes me think of that every time I use it. Staging is huge on the Shiro, vast and free while also somehow having big and bold features too. Light on it’s feet, less bombastic in the bass but still very textured and fast. If you want to bring AP a bit more into neutral tuning, the Shiro is a good choice. This very well may be my favorite of the bunch, makes the AP more suitable for all kinds of music.

-RSD CF gave the AP a healthy dose of more everything. More punch, more resolution, extra attack. Bass levels is about the same as stock, but reaches deeper, and has a lot more punch and toughness. Stage is much more spherical and holographic. Adds a little extra bump in the 8kHz region for extra bite, but very tastefully so. Mids are clear and clean like 50S, but more modern sounding, more resolving and more musical too. Fantastic. There is something about the Rhapsodio tuning that gets to me, but if ergo is a concern then its purple rubbery wires might be a nail in the coffin. It’s not heavy, and the wire isn’t truly stiff, it’s more unfettered, with a mind of its own. I find it hard to wear sometimes only because it won’t lie flat, wanting to float and slide around. But staggering sonics, really, an amazing cable and amazing synergy with AP. If I ever went customs with AP I could imagine being able to handle the RSD’s ergo for the sake of its sonic prowess.

FTS - While I don’t have the FTS here with me now, I do remember it well. I did a full review on it a while back, loved it very much, though I always felt it took a backseat to the Orpheus. Very detailed, more punchy and less wide, more top end energy and sub bass focus over the Orphy’s uber analog wide but not tall vibe. In this case, with the AP’s warmth and Orphy’s bass bump, I could easily see the FTS being a perfect pairing. Deeper subbass, forward mids that aren’t as wide to lose engagement and vocal distance, creating a more W signature. Transients with sharper edges, to add a bit of energy to the AP’s velvety relaxed nature. A very tall stage. More punch and speed. Could be great.

I would love to test it, so anyone with a FTS laying around unused would be strongly suggested, or even coerced, to let me borrow and verify.


For the conclusion I thought to be honest and tell you a story. I bought the AP with the very last of my savings, I am not a wealthy person by any stretch of the imagination. After really enjoying it for a while, my struggle with the fit was irking me, then I stressed over the price, and was constantly comparing it to my Traillii in the extreme case I was forced to choose between them. It wasn’t ideal, and these external factors played heavily on my emotions, and my overall feelings about the AP. It got to a point where I let a good friend borrow them for a few days just to release the pressure. I was torn, and not sleeping. After a few days off I started to listen to music for enjoyment again, and no matter what I was listening to, I was missing the AP. Thinking about how it would have made me feel. Missing the bass. Missing the thickness, the BCD. Missing that character. I realized that I had never given the AP a chance to be what it was, only forcing it into a box of what I was expecting, and only with a price to value I was comfortable with. All of a sudden I wanted it back, needed it back, immediately. Thankfully my friend, who had totally fallen in love with them himself, agreed to hand them over, and I have been loving every second since. I just needed to stop obsessing over the details, over AB’ing and pairing, and simply step back and admire how insanely good the AP really is. Perfect no, but astounding yes. Tiger Thunder. Velvet subtleties. Musicality emblazoned with heart and soul. Sonic bliss carried by waves of sub rumbles. Vocals to die for. Easy to listen to for hours, while being extremely detailed. What UM have achieved to fit into these rather bulbous orange tiger shells is pretty stunning.

Now after my back and forth, rediscovery, and final settling on an IEM review filled with heavy praise, here comes the brutal honesty bit. Is it the best IEM ever? No. Is it worth the ludicrous price? Not really. Nothing is worth this price, it’s simply stupid. $8000 for an IEM, what are they thinking?!!? But does it do what no other IEM can in its own way? Absolutely! Do I love it and cherish it? You bet your a** I do. If it was $4-5k I would recommend it as perhaps the best summit allrounder available now, for those that like a little extra bass. While I personally would have prefer it less bottom heavy, I got into it and loved it after my brain adjusted. That. bass. is. epic! The mids are lust-worthy for sure, so velvety and lush. A top end that anyone would love, easy to listen to and with great air and space. It is amazing. But the slight V shape and bass shelf could be divisive to those looking to enjoy things without the heavier bottom end, and with an emphasis on mids, not just great mids. My personal recommendation for the all rounder would probably still go to the Traillii, just because it is a bit more neutral, and I simply couldn’t find a genre that it doesn’t handle perfectly. It also sounds amazing from a phone, where the AP is no slouch, but needs at least better gear to shine. The AP shells are too big for me, but I am learning to deal with it, Traillii also has a divisive for the opposite reason funny enough. They both sound huge, but go about it in different ways and are dramatically different shapes. For my tastes, AP sounds sublime for some genres, and simply great for others. For a $8k IEM that’s quite the pill to swallow. That is only my personal feeling, I’m more of a reference guy, though the AP does continue to grow on me more and more everyday I listen to it. It’s unapologetically fun, huge and powerful, and a tad bass heavy. I’m probably in the minority here, I do know a large part of the population rightfully enjoys a little extra thunder down under. Rumble in the jungle? Tigers love a little thunder I’m certain, at least as far as it fits my metaphors and review mythology. There’s an expression that fits here, but l’ll be stopping now and saying it clearly and simply - this is a fantastic IEM, for an insane price. If you like this tuning, and you have excess cash to burn, I recommend the AP highly. If you’ve bought one you should cherish it, forget how much you spent on it, and just enjoy. If you don’t have the cash to spare the Mentor is a good choice, or even the Mason FS which can procure some of the same/similar BCD experiences, though it does lack the bombastic approach the AP takes. Traillii is great too, a classic that somehow through the passage of time only seems to garner attention and respect unlike the rest of the TOTLs. The AP is different, and only time will tell if it’s going to stick around at the top of the summit. S it sits now it’s certainly one of the best in the world, and fittingly, one of the most expensive. It is really more than the sum of its parts, which is what makes it so special. If you like a fun tuning with amazing yet musical technicalities the AP is hard to beat. Just don’t empty your kid’s college fund for it, nothing is worth that.

Thanks for reading!

If anyone is looking to pick up the AP for themselves I cannot recommend MusicTeck enough. I have no official affiliation, just passing on my personal experiences that Andrew is a Gentleman and a Scholar, and is the nicest guy to deal with when shlepping out all your hard earned dough on gear. I heard there is only a couple APs left, and when they’re gone that’s the end of that.


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