BT Magic makes some noise

I found that my new BT Magic makes periodic noise on the left unit connected to Tone2 Pro.

Here’s video I took to record the noise sound.
The noise is very small. High volume is required to listen the noise.
You can hear popping sound every second in the first video.

This is the video with BT Magic.!AgcJN-fTHU5Ngbo2fu2DwHSEeKSH3A?e=FeNw4r

This is the video without BT Magic.!AgcJN-fTHU5Ngbo1GqV4BTtQNVT7cA?e=3eHh3N

Is there any solution or suggestion to fix this problem?

These are other peripherals.

  • I replaced the left unit to the right unit, but the noise still remained left side.
  • There is always noise regardless of the volume & source setting.
  • Unfortunately, I don’t have other I2S device. So I couldn’t figure out the cause of the noise: Tone2 Pro or BT magic.
  • I know the noise is very “very” small to hear when I listening to music, but I’m not playing music all the time and the noise becomes very annoying when I need silence.

I want to make sure some questions with you.
1.Noise exists when tone2 pro connects to bt magic whenever the music is play or not;
2.Noise does not exist when tone2 pro disconnects to bt magic when the music from USB is not play;
3.Noise still exists when tone2 pro audio source from USB is play;
4.Our RCA is balanced RCA,it can use for both balanced and unbalanced RCA plug.what kind of audio connect is your loudspeaker? Single end RCA or XLR-3?
5.Your loudspeaker has independent power supply.

Hi, Eric68.

Here are the answers to your questions

  1. There is always the noise when the BT Magic is connected whenever music is played or not: I checked it by playing an empty sound.
  2. There is no noise when the BT Magic is disconnected, whether music is played or not. You can check it in the second video link I uploaded in the main article.
  3. There is always the noise regardless of the volume, playback status & source settings.
  4. The speakers I use are 8010A active speakers from Genelec. It uses an XLR-3 connector and I connected it with Tone2 Pro with Bal-RCA to XLR-3 Cable(K-RCAX-M01).
  5. The speakers are connected to the power socket independently. But I don’t think the power configuration is the problem. The noise always remained left side even when I replaced the left unit with right unit and vice versa.

Thank you for your interest.

I know your loudspeaker and its connections. I am also confused these two questions below.

  • The noise exists when bt magic connects to your tone2 pro whenever music is from USB or bluetooth, no matter whether the music is play or not. Right?

  • The noise does not exist when bt magic disconnects to your tone2 pro and music from USB is play. Right?

Yes, the sound source and the playing status doesn’t matter to the noise.

Yes. If the BT Magic is connected, I can hear the noise. If the BT Magic is disconnected, the noise disappear.

I’ve changed hardwares: the speakers, the sound source and the power source, but there was no change of the noise.
And I’ve changed the setting of the Tone2 Pro: the volume, the sound source(USB, I2S, Auto), the playing status(stop & play), and the gain setting(Low, High, Pre-amp); but there was no change either.

The only condition that I found to remove the noise is disconnecting the BT Magic.

Thank you for your quick-reply. :slight_smile:
I hope the solution can be found.

OK,there is something wrong with the bt magic,could you send it to us to check please?

Sure, I bought it from a week ago. I’ll contact to the seller about sending it back.
But I’m afraid in case of the Tone2 Pro is the cause of the noise… :frowning:

You’d better to send both tone2 pro and bt magic to us to check if you are afraid of that.

I have used the APx555 to test the RCA output noise of tone2 pro when I plug bt magic into tone2 pro. The result is following below.

  • From the first wave diagram,there is some peak voltage which may be possible to make the noise. But it is so weak,just 35uV.I have used our speak to have a try, I cannot head the nosie.

  • I also find that if I use 5V/500mA to power tone2 pro the nosie is more obvious,I think you can use 5V/3A adapter to supply tone2 pro.

  • Another information is that the peak noise will be weaken 30 seconds after bt magic power-on.Beause bt magic needs to more current when power up.So you can try to wait the time to head if the nosie is still exist.

Hi, I checked the BT magic using several Tone2 Pros with local distributor in Korea.
There was the same periodic noise I described with other Tone2 Pro.
So I sent the BT magic and the return process is on going.

I heard that the package is already arrived to you.
Would you check the noise with the BT magic I sent?
I want to know whether the one BT magic I received has a problem or every BT magic have the same characteristic.
Because I was very satisfied with the Tone2 Pro and I want to buy BT Magic again unless the noise is a design issue. :frowning:

The noise is noticable at a high gain and it appears only on left channel.

I have received your bt magic and use it to connect our tone2 pro to test the RCA noise, the result was just the reply I sent to you 4 days ago.
Could you try the second and third methods?

Sorry, I don’t know how 35uV small is, but as shown in my video, the noise is even recordable with mobile phone. Would you give me more information about your measurement? I want to know whether the peak voltage you found represents the noise I heard.

  • Is the wave diagram shows one period of the noise? The noise I heard was periodic and its tempo is around 80bpm.
  • Is the peak voltage does not appears in the right channel? I heard the noise in the left RCA channel only.


  • Yes, weak noise persists for 30 seconds after power-on.

  • The peak voltage appears in right channel and left channel. It is strange that you heard the noise in only RCA channel.

Okay, Then the periodic voltage spike is confirmed and the symptom may differs by each tone2 boards: scale of the spike & output channel.

Now what I want to know is this: Is the BT magic I received only makes the voltage spike? Or, every BT Magic makes the same?

If is this problem is not the design issue and the normal BT magic does not make the spike, I’m going to buy new BT magic once again.

Thank you for your time.

Yes, bt magic makes the voltage spike, but the noise you mentioned may be caused by another reason. It may be the power supply for tone2 pro.