YUIN PK1, a review
Jan 26, 2007 at 4:11 AM Thread Starter Post #1 of 30


Nov 28, 2007
Ok so I first heard these little buds at the NYC meet, 82 days later, I finally feel Ive spent enough time with them to share my impressions.

I bought these used, and they seem to be an earlier model for there were no "L" and "R" markings.

The burn in issue has definitely been settled as I have rotated these with my other cans at night for a good two months now, so it is over 250 hours.

When inserted into this chain-- FLAC-> m-audio a192-> LDII+-> PK1
(I left out the newly acquired dac and sacd player because Ive not spent enough time yet <100 hours and have not yet fully analyzed and appreciated the great benefits) I have used the LDII+ straight out of the m-audio card for a very long time and it is what I am using as a reference.

I remember the first extended listening session I had with them on, and still to this day, my thoughts remain firm that these buds have a sound that is most comfortable to me.

Oh and these things aren't the most efficient things in the world, and would be much happier with a good amp.
Synergy? Well Ill put it this way- It sounds marvelous with my LDII+, especially with the Mullard M8161 tubes (tuberolling impressions comin in another thread). The portaphile? Here is where it gets tricky. IMO, the PK1's have a sound signature that closely resembles what the v2^2 imparts onto other cans! In other words, the PK1s are the very headphonication of the amp. It multiplies the articulate and honest bass, the transparent midrange, and the detail retrieval in the highs sans sparkles. I feel it would be a great advantage if these buds were used at work at a desk with a tube amp, and from what I hear, it would pair well with a punchy warm hornet.

Ill begin with the highs. The detail is there, liquid and smooth without being overly harsh- it blends in very well throughout the whole experience. Compared to the super.fi 5 pros, I think the PK1's definitely triumph in this category. Against the K501, its a different story, though the 501s are not as balanced as the PK1's. When listening to Björk’s Vespertine, I find that tracks 5-7, Pagan Poetry, Frosty, and Aurora sound particularly atmospheric. The airy sound is there, detail is there, soundstage in the highs there, and what wasn’t there were the peaks which sometimes can be fatiguing.

Mids are very strange sounding. The whole experience suggests a rather large soundstage for a bud, but the energy is still there. Again, I would say that they sound very liquid unlike the K501's. I love the grado/ksc75 mids, and am quite happy that these buds stack up nicely in that you get a taste of the excitement of a midrangy can like the 225s yet am not detracted from the holistic approach it takes to the sound. Of course not as finely revealing as the 225's but then gain more than my ksc35, which happened to be a victim of its own bass. There is a nice balance that was lacking in the ksc75's. There seemed to lack gradients between the mids, highs, and lows- the transitions, which is somewhat existent in these buds and that makes for an enjoyable listen.

The lows strike me as amazingly textural and refined. There is no hump, added presence, or any other kind of gimmick here. All I hear is bass that reflects as much of the recording as possible. The second track of Oakenfolds Bunkka, Southern Sun, there is a bass loop that is very unusual. The bass is there in two situations- very poor headphones which reproduce it in flabby booms, very fine headphones like the HD580s which IMO DO have bass. The PK1 falls in the latter category. The bass background came through as a deep vibrations yes with each note you could actually tell a difference in timbre, as you could did on my 580/dac/amp setup.

The whole picture? When I hear the crack of a drum, I don't hear some monotone poof, fart, or vibrating plastic noise, but rather I am presented with the whole picture, from the crisp attack, articulate low end thump, and finally an almost transparent decay(obviously since they are buds and exhibit very little vibration). I particularly enjoy the layering, especially with my classical cds. It lets the ADD recordings come alive (especially Beethoven's 5/7th,kleiber, DG) which formerly sounded poor, almost unbearable with the super.fi's. I know that I enjoy the KSC35 the most with that recording, but then again, only with resistors which totally color the sound. Since they react to amplification quite noticeably, it would also mean you could tailor the sound to your tastes later on.

The most interesting thing about this little pair of buds is that it fills in a niche usage area that I really don't believe anything else could. These buds cannot be used satisfactory without an amp, there is no isolation, the soundstage is not as proficient as some full sized headphones, and well, they are expensive and don't look sexy. So what got me excited? Well, Ive discovered that most of the daytime working purveyors of fine headphones have office jobs, are students who frequent the library, or those that stay at home. Usually we don't want any type of isolation that could detract us from an important call, someone entering the office, etc. Students who are in a library or dorm room(except during "happy hour") have little need for isolation too. They don't want ostentatious full sized luxury looking cans to attract potential robbers and pickpockets. During these times, and amp and a decent source is readily available. They will give you a hifi-y feeling with the balanced sound in the majority of your waking hours, which in my book offers value against its initially high price tag.

In the end, I would say it sounds balanced. I perceive detail without grain, a coherent midrange and soundstage, and very importantly, a bass that is present, textural, and not at all overwhelming.

I wouldn't hesitate to give it a try now that TTVJ is selling them! Do give these buds a chance, because they might just be your thing, even if they are not, you still would lose nothing as you have gone up against the vanguard of earbud technology.
Jan 26, 2007 at 8:15 AM Post #3 of 30
Nice review Hydrocity. Can I contribute with my review? If I am thread crapping please let me know and I will start a dedicated thread of my own.

FWIW... My amp for all these tests was my Larocco PPA, misterX pimeta, and DIY Cmoy. I used a variety of sources, but mainly my D335 and panasonic CD deck.

I have had the PK1 for a month and have thoroughly enjoyed them, and continue to be impressed the more I listen to them.... So... Lets BOOGIE!!....

Plain-Jane, no frills earbud. Nothing flashy nothing gimicky at all here to really get too excited over. Don't let the ho-hum looks fool you. Inside lurks the MOST DURABLE headphone I have ever owned, and MOST COMFORTABLE headphone I have ever worn.

About a dozen or so times I have fallen asleep ON it at night, only to wake up in the morning with a tangled wad of headphone under my back (FWIW I am 5-11 and 200 pounds). I did this several times, and every time the PK1 bounced back unharmed. There have been WAY (!!) too many speculative comments and posts slamming Yuin phones for being cheaply made in asia of inferior materials. Let me put all that BS to rest once and for all... The PK1 are BY FAR the most durable headphones I have ever worn. I would NEVER sleep on my other cans at night, they wouldn't survive that kind of abuse.

They are easily the most comfortable headphones I have worn too. They just lightly cling too my ears, I can hardly feel them. This however will vary greatly depending on the shape of your ear. Here are some pics...


Like the PK2 the PK1 has a wooden case enclosing a small cylindrical plastic carry case. It comes with a nice 1/4" adapter and 4 pairs of replacement earpads. Mine came with 4 bowls and 4 flat pads.

First thing that jumps out at me is how Fast, Snappy, Dynamic, very detail revealing these buds are across the spectrum. The PK1 reveals details in my music that only my RS1 and A250 are capable of recovering.

It has the rare ability to sound airy and light and articulate, without boosting treble. Very few cans in this price range can accomplish this feat. K501 is one that comes to mind, but its not something you can use portably, from a cmoy. PK1 treble is smooth, articulate and never harsh. Reminds me a lot of my RS1.... that same kind of rolled off extension. Treble in live recordings is the PK1 specialty. Crowd noise has a very real sense of distance and separation. Maybe a hair less ambient than the KSC75. But way more ambient than the MDR-EX90 or any comparably priced canalphone / IEM.

Smooth and detailed. Very articulate and refined. Not as forward and aggressive as my Grados though. Snare DRUM TONES!!! wow... these buds really do a nice job with snare tones. Quick, snappy airy with that sense of "dryness" that very few headphones can replicate. Just a hair less energetic than my RS1, yet still very real to life. The PK1 is about as close to Grado mids as I have found in a portable. PK1 mids beat out the KSC75, due mainly to the PK1 speed and detail resolution.

You've all heard me rant/rave about RS1/HF1 guitar tone replication... ad-nausium. Well... the king & queen mahogany have a new prince in the castle (and its not the SR60). Those detailed and fast mids work WONDERS for guitar replication. Even complex heavily distorted guitar passages shine through clear and detailed on the PK1.

This ones for the Metallica fans. You've never heard Kirk and james like this. Those speed-metal riffs and thundering power-chords are spine tingling. Dave Murrays Iron Maiden marshall JCM tones are equally impressive. Yngwie, Eddie, SRV, Brian May... I could go on and on... they all sound great on the PK1.

But theres sooo much more.... The PK1 also has the ability to back down and mellow out should the recording call for it. Diana Krall is Silky smooth, as is Sade and Jonathan Butler.

Smooth and detailed, aritculate... FAST and very dynamic. Lars Ulrich kick drum triplets really dish out the impact and speed. Compared to the KSC75 the PK1 is MUCH less sloppy and bloated bass-wise. The PK1 is just way more refined in all aspects of bass reproduction than the koss.

The PK1 doesn't have quite the deep bass extension of any of my favorite cans (RS1, A250, HD580). But to be fair.... they are more bassy and extend deeper than any earbud I have tried (including the PK2). What the PK1 lacks in deep sub-bass extension it MORE THAN makes up for with speed, detail, impact and texture resolution. I'm a pseudo-bass head, so for me it came as a complete shock that a headphone with this kind of bass signature can capture my interest. They are just so detailed... I forget that the bottom octave (below 40Hz) rolls off gently. Fortunately most rock tunes don't have too much information below ~35 hz anyways. You read the ER4 owners comment on quality of bass over quantity. I think now I thoroughly understand where they're coming from.

I was playing around with my Foobar EQ and dialed in about 3 db of boost below ~75Hz. The PK1 handled it just fine. Never farting out or loosing its refined definition.

Three words on amplification for the PK1.... "they need it".
While I found them plenty loud straight out of my MuVo T100, they lost some degree of that speed and detail that makes them so special. They are easily detail revealing enough to fully reveal the sonic differences between all my amps. The higher up the amp/source ladder you climb, the greater your reward. I found the airy, ambient sound of my PPA clearly audible. The bass boost on the PPA works very well on the PK1 to fill in the lower octaves. Compared to my pimeta whos aggressive, forward presentation was just as easily perceived. I found my little cmoy plenty adequate for them. Pick your components wisely and a little $30 in parts goes a long way. I'm willing to bet a hornet, pint or 8397 based amp circuit will knock your socks off. OK... so thats a little more than 3 words.

Don't let the speed and detail resolution fool you though. They are not sterile, accurate or cold in any way. The PK1 is a Groovy, foot stomping listen. Its a very engaging kind of signature that draws you into the music... dare I say... Grado-like groove.

So are these for me? Thats the question thats nagging at members. That little man inside you that whispers... "You're about to spend $135 on a pair of earbuds." For that same amount you could get an HD580, K501 or SR125. While all are superior to the PK1 in sub-bass extension and soundstage, none can touch the PK1s portability, durability or comfort. I'd put the PK1 somewhere between the K501 and SR125 in terms of detail resolution. PK1 detail resolution quite frankly leaves the HD580 in the dust.

Ive seen ER4 sell for around that price used. ER4 of course wins out for isolation, but the PK1 beats it with superior image separation, soundstage and comfort. Its been a long time since I heard the ER4 though, so I really can't comment any further than that.

All my sonic comments are based on the foam doughnut sleeves. Without the foam sleeves, the buds fall out of my ears.

-Price, At $130 that places it Right in line with the HD580 and K501. Thats a TOUGH market segment to compete in, with those two soundstage / imaging GIANTS. But in all fairness, the PK1 is a portable earbud.
-Deep bass extension, below ~35hz starts to roll off.

-Speed / detail, impact and dynamic texture resolution
-Smooth balanced presnetation
-Not harsh or fatigue-ing
-highly portable
-Symmetric "Y" cord
-can sound aggressive and forward at times yet also laid back and mellow out when the recording calls for it. Outstanding in this regard.

Like ANY headphone, the PK1 has strengths and weaknesses. Members should keep this in mind and use their own "Value scale" to determine if the PK1 strengths outweigh its weaknesses.

Bottom line:
Based on my value scale, the PK1 is a winner. K501 levels of speed and detail resolution from a HIGHLY portable can. ER4 levels of speed and detail with soundstage and image. They very easily fill a vacant hole in the portable headphone market.

happy Listening!!
Jan 26, 2007 at 9:04 AM Post #4 of 30
Great reviews guys
I just ordered mine today and I can't wait to try them. Please post some close-up pix if you may. Does the PK1's have R and L designation? From other pictures, i don't see it.
Jan 26, 2007 at 11:20 AM Post #5 of 30
Just wanted to chime in here: had a chance to play with these for the first time today and am very impressed. pretty clearly the best sounding earbud I've ever heard. I don't know if we'll be carrying them soon (just too many other things we're working on at the moment), but I'd love to in the future. I've been looking for a good earbud for a long time, I think I've found it. I was hoping for a ~$80 price tag but I'm not surprised to see the solution pop the century mark out of the gate. Maybe with time we'll see the price go down, but they are a significant accomplishment to my ears (for an earbud) and a good reccomendation as long as your talking to someone who has plenty of disposable cash and wants an earbud specifically.
Jan 26, 2007 at 1:26 PM Post #8 of 30
Dear Tyll, Why not try PK2s? They are $69 and low impedance. Tips: Give them a little more time to burn-in.


Originally Posted by Tyll Hertsens /img/forum/go_quote.gif
Just wanted to chime in here: had a chance to play with these for the first time today and am very impressed. pretty clearly the best sounding earbud I've ever heard. I don't know if we'll be carrying them soon (just too many other things we're working on at the moment), but I'd love to in the future. I've been looking for a good earbud for a long time, I think I've found it. I was hoping for a ~$80 price tag but I'm not surprised to see the solution pop the century mark out of the gate. Maybe with time we'll see the price go down, but they are a significant accomplishment to my ears (for an earbud) and a good reccomendation as long as your talking to someone who has plenty of disposable cash and wants an earbud specifically.

HiFiMAN Innovating the art of listening. Stay updated on HiFiMAN at their sponsor profile on Head-Fi.
Jan 26, 2007 at 2:30 PM Post #9 of 30
In considering the review that Kramer gave, my wallet is just about ready to leap into action. I am guessing that they will sing with my Tomahawk. I have noticed over the years that Kramer and I share very similar tastes in music and sound signature preference. So to say I am interested in trying these litttle guys out would be an understatement.

Now all I have to do is get over the mental block of spending $139 on a pair of ear buds...

Just typing the words 'ear buds' gives me the shivers.


Does anyone know what TTVJ return policy is regarding Earbuds and IEMs? I can't seem to find his return policy anywhere on his website.
Jan 26, 2007 at 3:34 PM Post #10 of 30
It's good to hear they still do well un-amped. I've been enjoying my PK2's very much, however I just got my C&C Box (my first truly portable), and was thinking about upgrading to the PK1. I'm not always going to have an amp on me, so I need something that does well unamped.
Jan 26, 2007 at 4:14 PM Post #11 of 30
Thanks guys, I found both comments very informative and well written. I completely agree with hYdrociTy about a niche for high quality sound + minimal isolation phones.

Cheers for YUIN, it seems their great job was fully recognized here.

BTW no one told us yet do they leak sound?
Jan 26, 2007 at 6:23 PM Post #13 of 30
has anyone here compared the pk-1s to the v-moda vibes? that's what i'm currently using...and like them enough to have thought about getting another pair... but now i'm intrigued by the pk-1s.
Jan 29, 2007 at 9:05 PM Post #15 of 30
Wow, nice reviews.
I have had a pair of PK1 for a while but sort of sloppy to write a detailed review though. Most of the time I used it when I at home together with my er-4s, and there are both powered by my aged MG Head-DT. So far, the PK1 have been the primary earbud unless I was in a trip.
For the sound quality, many people have mentioned that they are great, which I totally agree. Compared to Er-4s, Pk1 has a fuller body in the lower frenquency. Thus, cello sounds much better with Pk1.
Concerning the cable quality problem some head-fier has mentioned, I do not find any problem in my hands for about 5 months yet.
Hopefully I have enough energy to write a decent review after I dig out my HD-600, and compare all these three phones together.

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