Piano World Home Page Forums Our Most Popular Forums Digital Pianos - Electronic Pianos - Synths & Keyboards Kawai Novus NV10 - line in volume level

Hello Giac,

Thank you for your reply.



Okay, I see.

So the hum only occurs when a cable is connected to the piano's Line In connector. In addition, this hum occurs regardless of whether that cable is connected to your computer or not, correct?

I will need to double-check, however, I expect leaving the other end of that cable disconnected from any device (the "freely" cable, as you refer to it) will probably cause a hum sound, as spanishbuddha notes with his NU1. For reference, my Nord also behaves in the same way.

However, a hum sound that occurs when the Line In cable is connected to another device is something of a mystery to me. I initially expected a Ground Loop hum caused by the USB cable, however you claim that the hum remains audible even after the USB cable is disconnected. By the way, have you also tried disconnecting the power from your computer (and running from the battery)?

If you have not done so already, I would recommend contacting your Kawai dealer and/or Kawai distributor (Furcht Pianoforte) for technical assistance. It's possible we may have missed something very simple that a technician will be able to resolve straight away.

Kind regards,
James
x

Hello Kawai James,
many thanks for your support. And YES, this hum occurs regardless of whether that cable is connected to my computer or not. I have a notebook very powerful that makes VST working for a long time with its durable battery. Recently I've also contacted my dealer (Furcht pianoforti) but he argues that NV10 is a very niche product so they have no technicians, so far, able to take responsability on doing something they have never done before (even if his service is top notch and one of the best!). I will have to wait much longer... Forum.pianoworld is my last resort right now. It may be a very silly thing but I don't know what it could depends on.
I've tried everything you said but it results a mistery for me too. Probably I forget something, but don't know what. Have you ever tested other NV10s affected by the same issue? Thank you for every single tip.

Hi Gombessa,
thanks for your tip. I know that we share the same configuration between NV10 and Garritan CFX (I personally don't require any external audio device).
Do you own any other accessory, in addition to usb and aux cables that I use? Or should I try other cables' brands? Which ones?
Which are the steps you do when preparing (such as settings, volume adjustments etc..) before starting to play the piano with Garritan CFX? Many thanks in advance.

Well, I do get a ground loop buzz/hum with my Macbook Pro, so I used a USB dongle called an IDefender 3.0 to reduce (unfortunately not eliminate) it. But if I unplug the USB cable from either the laptop or the DP, the hum stops completely (even if a line-in cable is still connected).

I have 5-6 stereo mini cables that I've used at one time or another, most are cheap/generic from Amazon that I purchased for various uses over the years. None of them cause a buzz when connected to the NV10. So I wouldn't recommend any brand in particular, as I feel they're all suitable for the purpose.

Garritan CFX is 100% headphones for me, plugged directly into the Macbook. So I don't typically use the line-in, unless I feel I want a change of pace. For speaker output I just use the NV10's native sound. On the occasions when I do plug in a line-in cable, I just plug the iDefender between the USB cable and laptop, and connect the line-in to the DP. The only precaution I take is to make sure the master volume on the NV10 isn't set too high, to avoid accidentally blowing out the speakers (or waking up everyone in the house).

Hello Giac,



May I ask you to send me a private message with your contact email address, please?

In addition, it would be useful if you could also send the correspondence that you sent (and received) from the dealer.

Thank you in advance.

Kind regards,
James
x

I tried a few more of my spare cables today, with interesting results:



All of these are fairly cheap freebie cables that have come with toys, car audio kits, PC speaker systems, or purchased from Amazon.

Most of them work fine. I can plug them in "freely" to the NV-10, without plugging the other end into an audio source, and turn the line-in volume knob to full. There is no hum. If I touch the tip or barrel of the connector, I can get a loud hum on the left (tip) or right (barrel) speakers, which seems normal to me.*

Two of these cables however, seem to have ineffective shielding. They will hum by themselves, and hum more loudly if I hold the cable in my hand or move the cable around (without touching the exposed connector). So I definitely agree with Mac to try a different cable and see if that solves the issue.


*Interestingly, I think the NV-10 may have a noise gate of sorts? If I plug a working cable into the NV-10 and touch the other end of the cable connector, it will cause a hum from the DP's speakers, but when I let go, the hum fades to a very low level, stays like that for a second, and then smoothly ducks to silence. I'm not sure what would cause that except for the DP monitoring the input and cutting it off when it senses no appreciable signal.

Thank you very much Gombessa for your very helpful experiments. I will make other attempts, as you suggested, in order to sort out this problem (only for me apparently). Today I also tested line-in on my Kawai ES8 and I experienced the same issue: when I plug one of the two branded aux cables in "freely" a very loud noise starts to increse from internal speakers. Any other ideas? Or the previous reasons can be applied in this case too?

If it happens on two DPs using the same cables, it's really sounding to me like the problem is with the cables and not the pianos...

Thank you for checking Gombessa.

Yes, based on your tests, I expect the issue that Giac is experiencing may be caused by the cables - especially if the same hum sound occurs when connecting to the his/her ES8 also.

Kind regards,
James
x

I think I've solved the problem.
When I use VST programs, installed in my notebook, I usually keep a bluetooth mouse's flash drive plugged: it has been very comfortable for my workplace, until now.
Today I made another final attempt, by chance; I removed the bluetooth flash drive and suddenly the speaker's buzzing noise went away! It only remains a soft hiss when I turn up the volume, but for me is tolerable. I knew that there was something dumb hidden in it, but I can't explain its reasons at the moment.
I hope my case might help other people that use the same setup. Now I can get back to normality and enjoy my NV10 again. Thanks you all for you time and constant support.

Was the flash drive plugged into the notebook connected to DP? Or into a USB port on the DP itself?

Interesting--do you still get the him if the cable is plugged into the DP but not plugged into the laptop?

The flash drive was plugged into the notebook connected to DP. I have two USB ports in the right side, next to each other, and only one in the left side of my notebook. If I plug the Bluetooth flash drive in the right side, where I always plug the USB type B and the AUX cables, obviously connected to NV10, I notice the buzzing noise I talked about previously. If I plug the Bluetooth flash drive in the left side of my PC (also with the USB type B and AUX cables connected in the right side) the noise seems to be a lot reduced. When I unplug the Bluetooth flash drive definitively, the noise goes away.

Not quite, I mean... Before I did another experiment. When I use the cable on the loose, without connecting it with any device, I experiment the same buzzing noise problem from the speaker (the issue persists by the way). Then I did a strange attempt: I rolled up the AUX cable and stucked it with a wire, connecting it to line-in port at the same time. The result is like a "ball of thread" dangling over the line-in port suspended in air, under the piano, WITHOUT touching floor: and by that the noise went away! This case made me reflect on some physical stuff (I'm not a scientist ahah...); I tried to move my hand close to the dangling cable and I noticed that the noise was coming out as strong as my hand was closer to the cable. What I can now deduct is that, in my case, when this "free" AUX cable (connected to line-in but not with a device...) is near something "human material", touching the ground or something else, the buzzing noise comes out the speakers. I think there is an electromagnetic interaction through the corps that causes this phenomenon: indeed, if I also touch with a finger the end of the AUX cable (the one that is not connected to line-in port) it generates a crackling from speakers. This is what I found out with the case of cable plugged into line-in port but not into the laptop. On the other hand, when I use my VST, I've just resolved with simply removing a bluetooth flash-drive from my notebook (previously explained).

This is why.

Thanks for the update Giac!

I'm glad to hear that you have managed to resolve this issue by removing the Bluetooth USB dongle from your laptop.

I wondered if this could also be related to the NV10's Bluetooth Audio controller, but recalled that you also hear the same noise on your ES8 (which does not feature Bluetooth), so it's unlikely to be the case.

Kind regards,
James
x