Up2Stream Mini v3: I hear noise and hum - how to solve?

I have noticed that the Up2Stream Mini seems to pick up noise and hum. When I stream music that is not too loud (like acapella, or just a piano), I can clearly hear noise and hum. It is permanently there, but sometimes the noise gets stronger like a sharp hiss.

My configuration is an active speaker of Bang & Olufsen, and a Up2Stream Mini v3 built inside the speaker casing. To power the Up2Stream Mini, I use a 230 to 5 volt AC/DC converter. The Up2Stream Mini’s WiFi-antenna is on the outside of the speaker casing. The antenna wire goes in through a small hole.

I have tested with an external power supply to the Up2Stream Mini, but this does not solve the noise & hum.
I did find out that when I touch the WiFi antenna with my finger tip (where the wire connects to the antenna strip), the noise and hum almost disappear.

Does anyone have suggestions to eliminate the noise & hum?

Hi @KolfMAKER , what external power did you try?

Have you tried 5V1A micro USB power supply for test?

Hi Joy, nice to hear from you!

For external power I have tested with a battery pack 5v power supply. The result was a bit less hum, but the noise was still the same.

What I use in my setup to power the Up2Stream Mini v3, is a 230v AC-to-5v DC converter = https://bit.ly/3eW6XzZ
According to the specifications it is an isolated step down converter.

Do you have any suggestions?

I had this problem as well when I first powered mine up. I first had it powered up through the USB port on my Yamaha receiver. I thought it might be some kind of weird interference with the Yamaha port. I then powered it up with an Apple 5v 1 amp phone charger base and a different micro usb cable and the noise went away. I have found the wifi antennae to be noisy as well and pass that noise on to the amplifier.

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I also consider the WiFi antenna to be the suspect.
Because I noticed if I touch the WiFi antenna with my finger tip,
the noise is much lower.

Have you een able to solve this issue?
How?

I haven’t had any more issues since changing my power supply to an iPhone 5v 1amp charger base and a high quality usb cable. I think my problem was power related with the noise. Have you removed the antennae and reseated it make sure connection is good. Also weird things happen and noise can be introduced into audio signal chains through cellular signals. If your phone is close to the unit and transmitting cellular data that can cause noise as well.

Also there could be some type of ground loop happening between your equipment. I’m not sure of your setup but if you have multiple pieces of equipment or a laptop in line grounding becomes a concern and can cause hum. Do the bang and olufson plugs on the active speakers utilize a ground prong on the power cord?

Hello,
I had the same issue, solved moving the wifi antena as far as possible from the board.
I hope it helps you.

Joan

There is no ground coming in via the power cord.
Could there then still be a ground loop?

That sounds interesting Joanb14.
Did you do that with the standard WiFi antenna (only 20cm cable)?
I have adjusted one of my speakers by moving the WiFi antenna as far away as possible. But it didn’t solve the hum & noise.

Yes, but I moved the wifi antena 20 cm far from the board not from the speakers, in the first setup I have it just near the board and after moving the noise disaperared. But the thing is, you can have some different sources of noise. Other option is use filters, I use filters for the DC power, mini jack line and between the amplifier and the speakers.

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Very interesting Joanb14!

  1. For the Up2Stream Mini to Amplifier connection, I use 4-pin connector on the Mini’s PCB. Is the mini-jack maybe a less ‘noisy’ connection?
  2. Can you share with me which filters you use?

Hi,
I use the 4-pin conector for the line also. But with this filter between my mini-jack and the 4-pin.

Fot the power source I use this one.

At the moment with very good results.

Joan

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Thnx Joan.
I ordered both already.
I will try if this solves my problem too.
And I will leave a message when I know.

Very interested to see if using the external antenna solves the noise problem. I would be interested to hear the noise if it is possible for you to capture it and post a short video. Joan suggestions were very good. One other solution I might add would be to add the DAC extension board and use high quality shielded rca cables to connect to your speakers. I haven’t purchased one yet but I’m going to as the sound quality out of the 3.5mm onboard Jack is not very good.

Dear Joan & Jzad,

In the meantime, I did another test with the WiFi antenna. By coincidence I have a fitting WiFi antenna with 1 meter of cable (see picture). So I connected this one and was able to have the antenne about 100cm away from the Up2Stream Mini PCB.

My conclusion: no difference, still hum & noise at the same level as with the standard antenna.

So I guess the hum & noise cause must be either in the power supply (ground loop), or in the audio connection between ‘Up2Stream Mini audio-out’ and ‘speaker amplifier audio-in’.

To be continued!

A friend of mine mentioned that many AC/DC converters put out high frequencies. So a possible cause of noise and hum. He advised to change the one I am currently using (this one) into this type.

The model that fits best is the 5 volt/2 Amp version.
The Acrylic manual for the Up2Stream Mini mentions “Warning: Up2Stream Mini must use 5V-1A DC input, higher voltage power supply may damage the board”

Question:
Does this mean that a 5 volt/2 Amp power supply is ok?

The higher voltage will damage the board as it’s designed to accept 5V. And the current need at least 1A for stable working as the booting of the board need it. And larger current output of adapter does not matter, as the board only consume what it needs.

Thnx zpl1025.

Does anyone recommend a linear or switched power supply?

I have my first experience with my UpStream Mini v3 today. I used some old skool bose powered speakers and a very cheap 5VDC power supply from my Samsung Phone. The Mini is very small but from experience with other hardware in the past (in particular powered active speakers) I have placed the mini 1 metre away. There is no noise or hum.

You could maybe try distancing the mini device from the Powered/Active Speakers ? Do you still have the same level of problem ?

Kevin