Cayin YB-04

disclaimer:  I was sent the Cayin N6ii and YB04 as part of the Cayin North American Review tour.  Thank you to Cayin for providing the opportunity and trusting me with their gear.   If you have an interest in Cayin products, more details can be found at Cayin’s Website.    Cayin products are sold in North America by Musicteck.


Unboxing / Packaging:

While the asking price is mid-fi, the packaging certainly qualifies as high end.   An outer slipcover keeps a book-fold style box closed for transport but is easily removed when needed unlike some that required considerable force to dislodge the inner package.   The inner box is equally divided with the tips, books, case, and accessories on one side, and a foam surround cradling the earpieces and cable on the other.  The foam has cutouts to allow easy removal and at the same time is a tight enough fit to protect the contents well.   The case is a rectangular leather clamshell type with ample room for the cable and earpieces without feeling crowded (Nice touch as too many are too small),   Multiple tip options are presented on cards to keep them organized, again, exceeding the norm at this price-point (more on this later).    The only hint that the YB04 is closer to mid-fi than flagship is the lack of a balanced cable in the kit.



The YB04 is a 4 piece shell consisting of nozzles, inner shell, an outer ring that seals the bi-pin connector to the inner shell, and a faceplate.   All except the nozzles are made of the same aluminum alloy and polished to a brushed metal finish. The nozzle, while also aluminum, is a different alloy and polished to a lighter and brighter finish than the rest of the shell.  Nozzles are T400 size with a pronounced lip f0r holding tips in place.   The nozzles themselves are fairly short, but sit atop a riser that is roughly the same height as the nozzle itself and offsets the nozzle significantly from the body of the earpiece.  This allows for fairly deep insertion.  L/R are marked on the Riser at the front of the earpiece with a colored dot immediately below the connector for quick reference.

Shells are on the large side, but sit mostly on the ear rather than in it so comfort is reasonable for long periods for me, but I would certainly recommend auditioning a set before purchase as they are larger than most.   Isolation is only average as the body does little to block the canal so realistically the tip is the only thing doing so.   While my first thoughts were these looked large, heavy, and uncomfortable, I found them to be more comfortable for long wear than things like the Hifiman Re2000s, or the CCA-C12 as these later two fit more in the ear than on and create pressure points which the YB04 did not.




Thy YB04 is a quad balanced armature using two pairs of drivers.  At the Low end, a Sonion made dual woofer package is used.  Cayin doesn’t state which but odds are pretty good it is either a 3800 or 3300 package.  My bet would be on the 3300 series as it is a bit flatter in the mids than the 3800.   For the top end, a Knowles package with two drivers is used.  Here again, no detail is provided but the most likely options are either a twfk or an swfk package.     Crossover duties are handled by a 2 way resistor/capacitor cross.  The pictures below show Cayin’s exploded diagram and a couple of shots of the actual internals of the review pair.   Nominal impedance is listed as 30Ω with a sensitivity of  113 dB/mW which makes the YB04 fairly easy to drive.  Having said that, the YB04 definitely benefits from more amplification than the average phone or tablet can provide and even the LG on high output is marginal.     Cayin of course recommends the N6ii as the prefered source for the YB04 and they do indeed pair well, but I found the Sony WM1A, Dethonray DTR1, Xduoo X20, and even the Shanling M1 to be capable of driving the YB04 well.   The YB04 scales qualitatively as well with more detail being heard with improvements in source.



The cable provided with the YB04 is a 8 core hybrid with 4 strands of oxygen free copper and 4 of silver alloy.  Strands are covered in a clear PVC giving the cable a pleasing striped look.   Starting from the south end, the cable starts with a straight 3.5mm TRS connector housed in a hexagon shaped metal housing that matches the color of the earpieces.  A small set screw holds the plastic strain relief in place at the exit of the jack.  the 8 core braid exits the strain relief and runs to the splitter.  The splitter matches the barrel on the jack and has a proper strain relief on the lower side and then exits as two separate 4 wire braids as the wire heads for the earpieces.  A small translucent plastic hexagon chin slider fits tightly to the top of the splitter when not in use.    The north end of the cable ends with pre-formed earhooks without memory wire and hooded bi-pin connectors.  The connectors themselves have clear housings, .78mm pins, and are well labeled with both L/R markings and a red dot on right for quick identification.   I hesitate to call these QDC connectors as they do not have the reverse polarity of the QDC but are similar in style.




As mentioned earlier, Cayin provides a larger than average selection of tips with the YB04 with bass, vocal, balanced, double flanged, and memory foams.   The bass/balanced tip options have recently become more popular as Simgot ships those two styles with most of their line, but the addition of the vocal to the mix is not as commonly seen.   While I started to write up something about each of the tips, I thought it better to let the measurements do the talking so I have included graphs of each compared to the default balanced tip.   I used the balanced tips for all my listening notes. insert in my canals. As a result they feel less comfy and they stick out. The seal is there but it doesn’t look or feel very nice. I’d need bigger ear canals for this tip selection.




Balanced tips used for Frequency Response graph.


Beginning at the bottom end, the YB-04 has typical sub-bass for an all balanced armature model.  Sub-bass is present, but not emphasized and falls a bit short of having that visceral feel most look for.  What is there is tight, fast and better textured than most, but it won’t please the bass-heads in the crowd and it may seem a touch lite even for those who prefer a more balanced signature.  Mid-bass is more present and follows the same pattern, fast, clean, and well detailed, but with a very slight emphasis that gives it a bit more presence in the overall mix and provides good slam when called upon.   The YB04 is somewhat tip dependent, and bass ranges from lite to near neutral to odd.  For me the bass tips gave an odd tonality when I listened using them so I quickly moved back to the balanced.



Mids are the dominant feature of the Yb04 but not in an “in your face” kind of way.  The very slight warmth in the mid-bass combined with a very linear transition into the mids gives the YB04 more lower-mid presence than most and a gentle push in the upper-mids brings vocals to the forefront.  timbre is mixed as the YB04 relies more on speed and articulation than brute force to deliver its message.  Acoustic guitar sounds more natural than its electric counterpart as a result.  Vocal presentation is engaging and well nuanced for both genders without sounding like one is in front of the other.   The best feature of the YB04 to me is the tuning of the upper-mids, they have enough energy to be well present in the mix, without that over-done feel that is so common to those models with the upper-mid/lower treble push.     These may not be as flashy or lively as some, but they are a much more natural presentation than most at this price point.



The mild upper-mid push is carried over into the lower treble with just enough added emphasis to really bring percussion to life without getting metallic or harsh.  High-hat has a satisfying clap and snare rattle is precise and crisp.   Detail in the lower treble is quite good which is almost expected from a ba anymore. Upper treble drops back a bit which keeps the Yb04 from getting fatiguing, but does add some air back into the mix and keeps the YB04 from sounding overly closed off.    The YB04 manages to walk a very thin line between feeling closed in and unnatural on one side and fatiguing and treble inflated on the other masterfully.


Soundstage / Imaging:

This is another strong point of the YB04.  The Stage is well dimensioned with a bit more width than depth,  and good height.  I’ve said that same thing about many iems, but with the YB04, the excellent stereo separation and imaging make the most of the stage and you lose some of the feeling that the shape is wider than deep as a result.   Seating the orchestra is straight forward with very defined margins between instruments and movement is easily tracked on the stage.  Layering is equally impressive with complex passages being easily handled without thickening or slop.



As a side note, Cayin recommends the YB04 be paired to the N6ii and I did find them to be a good pairing with the A01 module as the A01 is a bit warmer and thicker and the YB04 is a bit on the lean side so the combination really works.   The two play off each others strengths to deliver an really enjoyable performance.   The T01 module on the other hand is a bit thinner and more clinical and while yielding a near neutral performance, the combination came across as a bit lifeless in comparison to the A01.

Other than the N6ii, I found the YB04 paired exceedingly well with the Opus#1s with its slightly warm tilt and perhaps oddly with the iFi xDSD.  I say oddly as the xDSD shares the burr brown dac of the T01 card but was warmer and a bit more full than the T01 by comparison.


Thoughts / Conclusion:

2019 has seen a lot of companies enter the earphone market and a lot of others jump up price brackets to release models in the mid-fi space.  To say it is a crowded market is a serious understatement.    It has also been a year when the name Knowles has been tossed around a lot as if it was the holy grail of balanced armatures.   Sonion has quietly been building extremely good drivers and is giving Knowles a run for their money as evidenced here.   The fact that Cayin chose to source parts from both shows a willingness to go after the best components regardless of the extra complexity added to sourcing, balancing, and managing those additional moving parts.   A lot of other companies might have settled on Knowles or Sonion drivers to simplify the process.   The result of that extra work pays off in one of the best sounding freshman iems on the market.   It isn’t perfect as the size will scare some off and the lack of boosted bass will be the kiss of death for others, but the YB04 is a very solid (both physically and sounding) effort and shows that Cayin has some prowess in this space as well as in amps and DACs.     If you like an iem that has a natural sound on the thinner side without a big bass boost or an artificially warm signature, the YB04 should be on your list of iems to audition.   I am seriously considering shelling out for a pair when the tour package leaves my possession.  That probably says more than anything else I can.

Cayin YB04




Build Quality




Sound Quality

  • 6.5/10
    Bass - 6.5/10
  • 8/10
    Mids - 8/10
  • 7.5/10
    Treble - 7.5/10
  • 7/10
    Soundstage - 7/10
  • 8/10
    Imaging - 8/10


Pros –  first rate build and cable, neutral signature and natural tonality, great kit

Cons – Large shells, only average isolation, bass is neutral to slightly lite which wont please some.