I am unfortunately experiencing a very disconcerting issue from electrical noises - humming, clicking, sizzling - in my mobile setup consisting of N6ii, C9 and Beyerdynamic Xelento Remote. My interconnect cables are the stock ones that came with the C9, the Xelento is used with its stock 3.5 mm SE cable (no mic/mute) and an ALO Reference 8 4.4 mm BAL cable.
First, how do these noises sound:
- Like a continuous mains hum, though not exactly at mains frequency
- Plus continous clicking noises, like an estimated 10 clicks per second
- Plus superimposed sizzling occurring when nearing a hand towards the N6ii, and a tremendous sizzling like a hot fry pan when touching the N6ii screen
All these noises sound a bit like what musicians on stage create by touching cable plugs or sockets.
Important to remember: These noises are NOT the usual waterfall hissing of the IEM. They are superimposed upon the hissing, and they are much louder than that.
Second, very important to know: No connection whatsoever of any device to any mains wall wart, no chargers, all devices run on their batteries. No computer involved.
Third, the volume of these noises:
- Very faintly audible (with no audio playing) when I have the various gain and volume settings in my normal listening position, which is not a loud one.
- Well audible when I increase the volume settings to a higher level at which I would listen to music only for a few seconds.
- Increasing the volume beyond that point (say like > 1 o'clock on the C9, no audio playing) lets one hear the noises perfectly well and loud.
What I am saying is: Once these noises have been discovered, one gets more and more attentive, and they become more and more disturbing at normal listening levels or a bit above them.
Fourth, triggered by observing that the noises and in particular the sizzling show up when nearing a hand towards the N6ii: I can exclude WiFi as a reason; everything remains exactly the same in Flight Mode.
Here comes the most important part:
Fifth, when do these noises occur?
- The N6ii needs to be connected to the C9 with the 4.4 mm balanced Cayin stock interconnect for any of the noises to occur. I am using the Line Out of various N6ii DAC/AMP modules. As mentioned in other posts, this BAL cable by design has NO sleeve (ground) connection between its two plugs; out of the five TRRRS points, only the TRRR are connected along the cable.
- Using the 3.5 mm SE Cayin interconnect between N6ii and C9, all electrical noises are gone. Only the waterfall hissing remains. This cable of TRS type of course has the S's connected.
- Most importantly, these electrical noises occur very prominently when NO audio is being played by any of the apps, i.e. when the DAC/AMP is disengaged / muted. The engagement / unmuting at Play and disengagement / muting at Stop or Pause can be heard as faint clicks. When an audio replay is being started, the noises disappear to a good extent, i.e. they become very faint. I am using a Digital-Zero test track for this purpose, since real music could mask any noise.
- The noise level changes when the C9 volume pot is turned up/down and when switching the C9 Gain setting L/H.
- The noise level does NOT change when changing the N6ii Line Out Gain Lo/Mid/Hi.
- When I am in a situation where the noises are present, the clicking that emanates from the C9 into the room while the volume pot is being turned becomes a bit louder.
- The noises do occur alike for the other C9 setings, Timbre SS/Tube, Class AB/A.
Sixth, what do these noises depend on, and what are they independent of?
- I have discovered these noises only in the chain N6ii with any module -> 4.4 mm TRRRS BAL -> C9 -> any IEM cable type -> Xelento or another IEM.
- The Beyerdynamic Xelento (16 Ohm, 110 dB @ 1 mW @ 500 Hz) makes them most prominent. They do occur for both a SE and a BAL IEM cable from C9 to the Xelento earpieces. The noise level changes between SE and BAL IEM connections, probably according to the power available at either C9 phone output..
- Exchanging the Xelento with old Sony 16 Ohm earbuds (SE only) from a NWZ MP3 Walkman, the noises remain. They just are lower in volume, probably because these earbuds are less efficient.
- Exchanging the Xelento with my 300 Ohm Sennheiser HD 800S (SE driven from the C9), everything becomes dead quiet. I guess this is just due to the fact that such a 300 Ohm full-size headphone is no "noise and hiss detective".
- Exchanging the N6ii modules doesn't change anything. I tested A01 and E02 all line outs SE and BAL -> C9 -> IEM up to now. I could repeat it also for the T01 and A02.
- I cannot find noises of this kind when the Xelento IEM is hooked up directly to the N6ii, i.e. omitting the C9. There is waterfall hissing, maybe some tiny noise superimposed, but hard to tell. No sizzling when touching the N6ii sceen in this case.
Seventh, I conducted some more tests and exchanges:
- In order to exclude the Xelento as a sole reason, I used another chain: N6ii -> S/PDIF embedded in USB-C digital output -> Coaxial input into Chord Hugo 2 (on battery) -> 3.5 mm SE IEM cable -> Xelento. Super quiet. Does the Cayin-supplied USB-C to coaxial digital cable provide a "ground" connection between N6ii and Hugo 2?
- In order to check whether grounding the N6ii would help, I used the chain N6ii -> 4.4 mm BAL -> C9 -> 4.4. mm BAL -> Xelento again and connected the N6ii USB-C input to my laptop USB-A, with the laptop being connected to the mains power and ground. The humming / clicking / sizzling noise in question disappears, the N6ii doesn't react to a hand getting close or to touching the screen anymore. Of course, there are other noises coming from the laptop now, albeit at a lower level.
- In order to check whether leaving the C9 out of the equation would help, I set up a different chain: N6ii -> iFi 4.4 mm BAL to 2x XLR adapter cable -> desktop headphone amp Violectric HPA V281 -> headphone, where the only usable headphone is my Sennheiser HD 800S. All is super quiet, as maybe was to be expected with the HD 800S.
Eighth, what had I changed before discovering the noises in question?
- I installed firmware version 2.3EN over 2.2 EN, OTA method, one or two days before observing the noise issue. No problems observed during the process. Kind of hard to imagine that the firmware could be the culprit, but one never knows.
- No other changes, no software change. Actually, since the noises occur when no audio is being played, no installed software matters.
Nineth and finally, I think I would have discovered this issue earlier, if it had been present. I had done a few checks on waterfall hissing 1.5 months ago when my C9 came in, and I don't think I heard anything like my issue before yesterday. So probably the issue is new; but I am not 100% sure, since initial tests are always conducted in sort of a rush and are not as comprehensive as today.
Well, too bad, I don't have any real idea what to make out of this. I would like to ask for community help here, and I also set a link in the C9 thread (
https://www.head-fi.org/threads/cay...able-headphone-amplifier.943135/post-16412192) in order to reach a wider audience. And of course I would like to ask in particular for your help, dear
@Andykong.
- Any similar observations by anybody?
- What would you advise as next steps to understand this issue?
- Could this potentially be an issue created by the interplay between N6ii and C9 due to their designs, more probably the C9's?
- Is any one or are several of my devices broken?
- I am very unsure whether a single one out of the two Cayin devices would be a culprit, and which one, or whether it would be both of them? Or any cable? I think I can exclude the Xelento.
- What would you ultimately advise to check and fix this issue?
I would be scared a bit if the ultimate solution would be to ship one or several of my Cayin devices in for repair. Where to?
I am located in Germany.
My N6ii is 1.5 years old, my C9 a mere 2 months. The Xelento Remote is more than 3 years old.
I bought my N6ii with A01, T01 and E02 from an authorized local dealer nearby.
I actually bought my C9 and A02 from the German importer (Cayin.com, Mr. Thomas Deyerling), who was nice to deal with. (And I have an R01 coming in ...)
Their website mentions a Cayin service in Germany named Lyric Audio run by Mr. Stefan Noll, but my feeling is that he might be more into the big tube amps than personal HiRes audio according to some PR publication.
I would hope for a smooth process to arrive at a solution. On the other hand, sorry to say, I would be a bit afraid of this dreaded deadlock of "ship in" -> "we can't reproduce" -> "explain the symptoms again" -> "yes, we can reproduce now, but that is a normal behavior" -> "but it wasn't there in the beginning" -> "further back and forth" -> "ship back, be months without the gear". A process which I experienced some time ago, though not with Cayin.
