Cayin C9

Pair up – IEMs/Headphones.

When I was testing and taking notes of C9 pair up with various IEMs and headphones, I received a few questions from my readers asking about benefits of using C9 w/tubes vs N8 w/tubes.  Thus, I thought it will be an interesting pair up comparison.  Here, I was using N6ii w/E02 + C9 (Low Gain, Tubes, Class AB) 4.4mm BAL vs N8 (Low Gain, P+, Tubes) 3.5mm SE, volume matched in every example.

Also, the reason why I thought N6ii w/E02 + C9 vs N8 will be good in this pair up comparison because due to a similar pricing some might find adding C9 to N6ii to be a more cost-efficient upgrade than going to N8.  The DAC choice is important, but from my personal experience I find the amplifier section of the source to make it or break it!


Here are some of my favorite IEM pair ups with C9.

Oriolus Traillii – Both C9 and N8 have a wide soundstage expansion and holographic imaging with Traillii, but the width spreads more L/R with C9, depth/height the same but stereo separation is wider.  C9 tonality is a little warmer, with a fuller body, but it doesn’t affect the resolution or retrieval of details.  Another thing, while both have excellent macro-dynamics of vertical expansion, I hear better micro-dynamics with C9 when analyzing layering and separation of the sounds.  When switching SE of C9, the soundstage is narrower in comparison to BAL, but it is still wider than N8 SE.

EE Legend X – Interesting comparison here.  As expected, the soundstage is wider with C9 vs N8, while imaging is similar.  Also, I hear a smoother and warmer tonality of mids in pair up with C9.  But it wasn’t just the tonality, being more analog and fuller body, but also the quantity of mids that came up, making the sound more balanced in comparison to N8 pair up where mids/vocals are pushed a bit back with bass being more forward.  With C9 the signature of LX is more W-shaped than L-shaped.  Also, in LX pair up with C9 the bass had more analog texture.

64 Audio U18t – In addition to C9 soundstage being wider in comparison to N8, C9 also improves the U18t imaging, making it more 3D holographic, positioning sounds not just wider but also with more 3D depth.  Both C9 and N8 pair up well with U18t, give the sound more bass texture and even extra bass quantity, and they both give the mids/vocals more body and help treble with more natural tonality.  Actually, C9 was a little bit smoother in this pair up, but to my big surprise, U18t had more clarity and better resolution with C9 than N8, despite being smoother.  N8 is also quieter when it comes to hissing, C9 has a little more hissing with U18t, but I personally preferred a pair up with C9 here.

VE Elysium – Ely really does come alive with C9.  Both have a similar 3D imaging on a holographic level, but there is something interesting about the soundstage.  C9 is definitely wider than N8, but I hear more width in vocals.  But the most noticeable difference is in tonality, with C9 mids being warmer and having a fuller body, while still being very detailed and layered.  Ely strength is in the reproduction of vocals, and C9 scales up its quality relative to N8, giving vocals more analog vacuum-tube flavor.  Also, adding more texture to the bass, especially to sub-bass rumble.


Here are a few IEM surprises where I actually preferred N8 over C9, in most of the cases due to hissing.  But if you use iFi iEMatch, hissing goes away, dead quiet!

DUNU Luna – I do hear a wider soundstage when comparing C9 to N8, and the soundstage was even wider when I switched to 3.5mm of C9.  I actually preferred using 3.5mm of C9 because 4.4mm had a bit too much power for Luna and hissing level was higher.  With 3.5mm of C9 the hissing is lower and when music is playing, it is not even noticeable.  When it comes to tonality, C9 does add more body and makes Luna smoothers, but I wasn’t 100% sure if I like that because it took away some speed, making sound more laidback. Between C9 and N8, I preferred more transparent and revealing pair up with N8.

VE Erlkonig – this is a more sensitive iem where I do hear some hissing with C9 and N8, a lot more with C9 (BAL).  Both have a very similar wide soundstage expansion and close to holographic imaging; I was expecting to hear a bigger difference, but it wasn’t too far off.  The tonality of C9 is warmer, especially with fuller body and slightly more textured bass, while resolution and retrieval of details is the same.  Unlike Traillii, here the vertical dynamic expansion of the sound is very similar as well.  The main difference is in tonality with C9 being warmer.  Switching to C9 SE only yielded a slightly narrower soundstage expansion, while tonality remained the same, and it was still hissing.

EE Odin – I had higher hopes for this pair up with C9, but it wasn’t exactly the best match in comparison to N8.  C9 soundstage is wider than N8, even when I tried both 4.4mm and 3.5mm C9 outputs.  But I was expecting a warmer and smoother tonality with a fuller body when comparing C9 pair up to N8, but surprisingly found the opposite where N8 pair up was smoother.  That was one of the reasons I switched Odin to 3.5mm output of C9, but it didn’t help.  And on top of that, Odin hissing with C9 was noticeably louder than with N8.  I preferred Odin pair up directly from N8.

Campfire Audio Solaris – this one going to be short.  If you have high sensitivity IEMs, there is no way around it even if you switch to low gain.  The hissing is there and it is noticeable.  Of course, you don’t need amplifier for high sensitivity IEMs, but if you are still considering it, I wouldn’t recommend it if you are into instrumental or classical music where a black background is a must.  Otherwise, you will get all the benefits of expanded soundstage and more natural body in sound.



The full-size headphones pair up coverage is not as extensive, since I’m mostly use IEMs, but you can get some idea how it pairs up with demanding high impedance (ATH-R70x), planar magnetic (Empyrean), and classic Tesla dynamic driver (T5p 2nd gen) headphones.

Audio Technica ATH-R70x – These are my hardest to drive headphones (470ohm impedance, 99dB sensitivity) so I was looking forward to this comparison. Right away I noticed soundstage being wider with C9, not just subtle difference, but quite noticeable, especially for open back headphones.  Next, N8 in low gain wasn’t driving R70x properly, and I had to switch to high gain and still raise the volume to 56 while C9 remained at low gain, though volume was at around 50%.  Comparing the tonality, you can clearly hear N8 being a little brighter and less colored, while C9 added warmth and body to the mids without affecting its technical performance.  As a result, pair up with N8 was more transparent and a little faster, while with C9 R70x sounded fuller, warmer, and slightly more laid back.

Meze Audio Empyrean – The soundstage expansion and imaging have a lot of similarities between C9 and N8, just a little bit wider in C9, especially when focusing on mids/vocals.  Tonality had a bigger gap until I changed N8 gain to high, otherwise bass was very soft and mids were lacking clarity in low gain.  But even in high gain, N8 doesn’t reach the same level of sub-bass rumble as C9 which pushed Empyrean to have a better low end extension, which is noticeable.  Still, with either C9 or N8 the Empyrean sounds smoother and more laidback, and C9 has a lot more headroom to drive these planar magnetic headphones more efficiently while N8 has to be pushed harder.

Beyerdynamic T5p 2nd – The soundstage width in this comparison is quite noticeable, stretching T5p2 width more to the right/left, giving the sound more holographic soundstage and imaging.  Tonality didn’t change as much, both C9 and N8 paired up with T5p2 give you a natural smooth balanced sound with extra velvety bass texture, natural organic mids/vocals, and just enough tremble sparkle to maintain natural clarity and resolution, but I hear improved micro-dynamics and a little more clarity with C9 and wondering if this could be due to improvement in soundstage width and imaging which gives vocals more room to breathe.  It’s not a night’n’day difference, but I did enjoy T5p2 more with C9.


Page 5 – Pair up with DAPs and Conclusion.

19 thoughts on “Cayin C9

  1. Great review Alex! One thing to point out, in my experience, is that using N6ii/A02 paired with the C9 creates a pitch black background for the Odin, seemingly unlike the N8, and is an incredible combo.


    1. If you unplug input to C9 while Odin is connected, do you hear this waterfall type of background hissing? Or when you pause your source? I spoke with a few people who do hear it and others who don’t, such as yourself. So, I’m puzzled now… I can only speak based on the sample in hand, wish I can compare it to another C9. My Odin doesn’t hiss with any daps except N6ii and C9 is quiet with most of the iems, except sensitive Campfire and Odin which is kind of an anomaly. And I tried different daps with C9 and Odin, the same results, even without dap connected.


      1. Doesn’t matter, high or low gain, tube or solid state, Class a or ab. But only with Campfire iems which is expected since they hiss with everything, and Odin which is a bit of a surprise to me.


    1. Been told BX2 was updated to BX2+. BX2 has imbalance at low volume so hard to use for iems. BX2+ fixed that, but I still feel it has way too much power for iems. BX2/+ is better for demanding headphones.


      1. Thank you very much. Your opinion makes my life easier on decision making.
        Do you think EE Odin is not a good pairing with C9 even with iematch?


      2. A more important question, why do you even need such a powerful amplifier to use with a pair of IEMs that sounds great straight out of your smartphone? Perhaps my ears are too sensitive to hissing or maybe something is not 100% right with my C9 review unit since a few people mentioned their C9 is dead quiet with Odin. But I don’t see a reason why anyone would need such a powerful amp for Odin. But if you do want to use it with Odin to color the sound, iematch works great. Iematch is impedance adapter that will change Odin sound slightly, making it warmer, which is what C9 will do anyway. So, if we are talking about C9 + iematch + Odin = great combo indeed that works for my ears 😉


      3. I have tried EE Odin from my daily driver…Lotoo Paw6k. It sounds weird.
        I have tried EE Odin from N6ii E02. It sounds ok.
        Lastly, I have tried EE Odin from Chord Hugo2. It sounds good!!
        So I assume EE Odin need more power to let it sing 😛

        Will demo the pair when C9 is available in my area.

        Appreciate your comments. 🙂


    1. Of course, my personal preference, but I’m not too crazy about this pair up. These earbuds do like power, but they have a thicker warmer fuller body sound to begin with. Coloring it with tubes makes the sound even smoother which takes away some resolution. And even when I switch from tube to ss on C9, I feel the sound is still colored. This is fine with some iems/earbuds/headphones, but not with VE Sun dice/copper. In this pair up I prefer a cleaner and more transparent Romi Audio BX2.


  2. Hello!

    Wondering how you think the Romi compares with the C9 when paired with the Empyrean?

    Looking to getting the latter and wondering if the Romi at less than half the price is a better match regardless, given how the Empy is warmish to begin with. Would be using the DX300 as the source/DAC.

    Appreciate any thoughts you might have if possible!


    1. For Empy, BX2+ will be a more cost efficient solution. BX2+ is super clear and transparent amp. Now, regarding dx300, wait for amp12, should be soon. It will have a proper dedicated LO, will be better for use with external amp.


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