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

[KolfMAKER]

Thank you NWT.Stuff, for sharing your thoughts.

I am unfortunately unable to have this large distance between the Up2Stream Mini and the active speaker. Everything has to fit inside.
I do understand that this is a way of checking if the noise/hum goes away. Though it still doesn’t proof where the problem is: is the Mini the suspect, or the power supply to the mini?

In the meantime I have consulted an experienced audio/streaming technician. He advised me to change the power supply I have to this one: https://bit.ly/348EXCP. This is a shielded, ‘distortion-cleaner’ power supply.

I have ordered them already, and will update here when I have implemented this.

[NWT.Stuff]

@KolfMAKER. Good luck and fingers crossed

Out of interest what B&O speakers are you using ? I do have access to beolab 4 powered speakers ?

Kevin

[KolfMAKER]

Hi Kevin,

I work with a variety of B&O speakers, most of them active. Though I intend to do some projects also with passive speakers.
But I also work with other speaker manufacturers.

[NWT.Stuff]

Again Good Luck with the change in Power Supply. Will be interested in the results

In my experience with Powered Speakers they are susceptible to wireless interference. (e.g. Microwave Ovens, Routers, Wireless Access Points etc.). In addition I have not come across a product yet that has both wireless transmission and reception (usually wireless reception only e.g. JBL Control One Active). Also I have noticed that quite a lot of powered speakers don’t have an earth connection via the mains (e.g. B&O Beolab 4, JBL, etc.).

Just thinking aloud as I am not an expert !! Could this make these devices more sensitive to wireless interference ?

I have done many applications in my own house of home networking (not just audio) and for clients that I service I do have a basic rule of thumb that I recommend and (particularly) if I am selling them the hardware too. This is if the device is static (in one place) it must have a wired Ethernet Link and a Static IP Address.

In the light of current Smart Home Stuff where there is so much kit around with a wireless Ethernet Interface ONLY it will be very hard to keep this "philosophy)

If the power supply doesn’t resolve the problem you could try moving up to the " Wifi Stereo Receiver for DIY Speakers Up2stream Pro V3" For an extra $10 is has a wired LAN Port and is still vey compact. If I were approaching an integration of Acrylic Boards in a Powered Speaker I would use this and disable the wifi completely. It’s always given me better results and reliability to use wired ethernet. Also leaves the wireless bandwidth for all the phones and tablets in the house

Also with these type of audio products there are issues with discovery of services with some routers. Hard Wired gets round the Firewall and makes it quicket to install without additional port configuration.

Hope this helps

Kevin

P.S. Will try to replicate your problem with the mini

[KolfMAKER]

Thanks Kevin, for sharing your extensive thoughts. I can always find some ideas and inspiration from it.

You are right, this speaker also has no earth connection to the mains. This made me think to create a earth connection just for testing. At least I can then exlcude if it is this type of earth connection or not.

Concerning the wireless versus wired connection. For me it is not an option. My purpose is to build a wireless speaker that has one wire only for power. Nevertheless, I can try to make an ethernet connection. Again for testing.

[Srdjan_Bajic]

I want to write my experiences similar to those listed in this forum. I bought two Up2Stream Mini v3 and tested them and I have noise on both. It is important to put the amplifier (on which Up2Stream Mini is connected) on the loudest sound when testing to get the right picture. Then this noise is heard.

I have Up2stream Pro V3 device too, and I can say that this sound is not heard on the Up2stream Pro V3 device, I assume the reason is probably that the audio output and amplifier are further away from the Wi-Fi module on that board than on the Up2Stream Mini V (Up2stream Pro V3 is larger board). I tried to put another 5V power supply, with flat voltage, and didn’t help. I am not sure this problem can be solved by adjusting the power supply or Wi-Fi antenna.

To check if I am right, I would ask someone from this forum who wrote that there is no problem with a sound, to try to put volume to max without playing music and to write if in that case he hears a noise. Thank you. Kind regards.

[NWT.Stuff]

@Srdjan_Bajic I have an S50Pro+, Up2stream Pro & Mini. Will test them all and get back to you. Regards Kevin

[KolfMAKER]

I am still in the process of finding the source of this problem. Unfortunately, I have not found it yet.

For my project configuration, please have a look at the first post in this thread, where I describe my configuration (BeoLab active speaker).

What I tried in the meantime:

• Power the Up2Stream Mini with a battery pack: no result, still high frequency noise is there.
• Power the Up2Stream Mini with a switched power supply: no result, still high frequency noise is there.
• Exchange the standard WiFi antenna for one with a 1 meter cord, so large distance between antenna and Up2Stream Mini module: no result, still high frequency noise is there.
• Changed my audio wiring between Up2Stream Mini and Audio-IN on the speakers amplifier, to a shielded cable: no result, still high frequency noise is there.

I think it has not to do with the power supply. My feeling is that the noise is a high frequency (RF?) that is picked up somehow, and amplified. When the amplifier is on without music, this noise cannot be heard. Only when music is coming through the Up2Stream Mini, the noise is there.

I hope also Arylic/Rakoit members can pick this up and help us. This is a serious issue.

[NWT.Stuff]

@KolfMAKER which beolab speaker.are you working with? Do you schematic electrical drawing that you can post or send via email. Regards Kevin

[NWT.Stuff]

@Srdjan_Bajic what amplifier are you using ? Will try to select something of similar design principles for testing. Regards kevin

[KolfMAKER]

Thanks for helping to find a resolution Kevin.

The B&O Speaker is a BeoLab 8000. The amplifier board of this active speaker has a P4 connector, which is for audio-IN. (It is a JST PH2.0 3-pin connector)
I have unplugged this connecter and reconnected it with the Audio-OUT connector of the Up2Stream Mini v3. This works perfectly for streaming through the BeoLab 8000. Besides the hiss/noise of course.

There is something specific about the BeoLab 8000 amplifier. It has an auto standby switch. It means that the amplifier switches on when music is coming to the amplifier. And it switches back to standby when music stops. I have succeeded to also make this work with streaming input form the Up2Stream Mini.
Also specific is that the B&O amp uses one channel (for instance left) for the audio signal, and the other one (R) for triggering the auto standby switch. If I only connect one audio channel to the B&O amp, it will amplify music, but also cause an additional hum and it won’t switch back to standby when music stops. So, both L & R audio signals from the Up2Stream need to be connected, although the speaker is of course just one channel/mono.

Also I thought that the audio cable between the Up2Stream Mini Audio OUT and the Audio IN on the B&O amp, might be the issue. Since it wasn’t shielded, I thought it might pick up high frequencies like a kind of antenna. So I replaced it by a shielded cable. But still the hiss/noise is there.

Hope this info helps you.
If you let me know your email, I can share schematics.

[NWT.Stuff]

@KolfMAKER @Srdjan_Bajic my email address is nwt.stuff@gmail.com. Would you both say that the noise/hum is completely independent of which channel you are using ? 1. is the noise spread nicely over both L/R channels ? 2. Inversion left to right and vice versa has the same overall result? Regards Kevin

[SimonB]

Hi

I’ve used the Up2Stream V3 mini in a few projects and haven’t had a noise problem. I’ve generally powered mine with DC-DC or AC-DC converters too, an example is in the circuit diagram on this page: Cambridge Audio A5 Amp with Arylic Up2stream Mini V3 Streamer

In the Cambridge example, the wifi and bluetooth aerials were fitted directly into the chassis of the amp. It’s a shame I don’t have a spectral plot to show you, but would have measured it and I’m fairly sure there was no noise.

Be careful you don’t assume you won’t have an earth loop because you’ve not got a mains earthed PSU. The loop could be elsewhere.

To fault find, I’d start by testing the Up2Stream V3 module on it’s own with headphones to see if that has a problem.

[SimonB]

The spec says it must be a 5V DC PSU which can provide 1A or more.

In practice the Up2Stream Mini V3 doesn’t even need 1A so in my design I opted for the Traco 4-4811 that will only supply up to 0.8A.

Can you sketch and/or photo how you’ve connected the Mini V3 and post it here?

[Srdjan_Bajic]

First let me say thank you to everyone for wanting to help.

@KolfMAKER WT.Stuff question: what amplifier are you using? Will try to select something of similar design principles for testing.

Answer: I have been using Up2stream Pro V3 for a long time. It is connected to a vintage Sony TA-1140 amplifier on the line-in and it is powered by a phone charger. Very simple. It is important to repeat that this is Up2stream Pro V3 not Up2Stream Mini V3.

Since I was very pleased with how it works, I started with a project to make another system with Up2Stream Mini and a small TDA7297 amplifier purchased from aliexpress. That one is one on which I found out about sound problem. Up2Stream Mini and the TDA7297 amplifier I put in a small box I made. The power supply is from IBM laptop AC Adaptor 16V, 4.5A for amplifier, and I make 5v for Up2Stream Mini using the Step Down Power Supply Module Mini DC-DC 12-24V To 5V 3A.

When I put it together I heard a noise and first I thought it was because of the power supply or maybe because of audio cable between the Up2Stream Mini Audio OUT and the Audio IN. So for testing purpose I took the Up2Stream Mini out of my project and connected it instead of the Up2stream Pro to a large Sony TA — 1140 amplifier, and there is also noise. It is totally another amplifier and another power supply I used in project and shielded audio cable to Sony. So I’m pretty sure it has nothing to do with the power supply and amplifier. Since I bought two Up2Stream Mini devices for the project, I tried both and the same noise is heard on both.

@NWT.Stuff question: Would you both say that the noise / hum is completely independent of which channel you are using? 1. is the noise spread nicely over both L / R channels? 2. Inversion left to right and vice versa has the same overall result?

Answer:

1. Yes the noise is the same and of the same volume on both speakers. Like @KolfMAKER said it sound like some high frequency noise and it doesn’t matter if I move WiFi antenna.

2. It doesn’t matter if I’m doing an inversion.

I will try to attach some photos and sound if it is possible.

Thank you all. Kind regards, Srdjan Bajic

[KolfMAKER]

Thanks Kevin & Simon for your response! Thanks for hanging in to help me solve this issue. For me this is a ‘don’t give up’ case.
I will respond to both if you in one message. And I will additionally share some tests I did and their outcome.

Noise: let me say something about this, as the definition of noise is sometimes explained differently. The noise I am experiencing is not constant; it varies a bit like a high-pitched whistle. I believe some people call it hiss.

The BeoLab 8000 active speaker (See this link) has 3 speakers and a bass reflex pipe. The bottom and middle speakers are physically the same, but the bottom is driven as a woofer and the middle one as mid-tone driver.

The noise/hiss I have can mainly be heard from the mid-tone driver.

Test music: I mainly test if the noise/hiss is still there playing ‘Bob Dylan, Man in the long black coat’. In the starting seconds the music is low but present, and the noise/hiss can clearly be heard. Listening to this same recording via headphones, there is no noise/hiss. So I am sure the noise/hiss is not in the recording.

Q Kevin: Would you both say that the noise/hum is completely independent of which channel you are using? 1. is the noise spread nicely over both L/R channels? 2. Inversion left to right and vice versa has the same overall result?

Answer: yes, it is spread over both channels, and it is evenly on both. Inversion L to R and vice versa has the same result.

Schematics overall: See the picture below for a drawing of how my setup is connected for both power and for audio signal.

Power supply to Up2Stream Mini: As I have built everything inside the speaker casing of the BeoLab 8000, I am tapping 230 volts from where the power comes into the BeoLab. This goes directly to a separate 230v DC-to-5v AC power supply, which feeds the Up2Stream Mini. I have tested two of those power supplies (both 5v, 1A):

• First one: see this link
• Second one a switched power supply: see this link

I have also tested powering the Up2Stream Mini with a battery pack. But in all three cases, it makes no difference, the noise/hiss is still there.

Up2Stream Mini signal test via headphones (Simon): As suggested I tested the audio-OUT signal from the Up2Stream Mini via headphones. In this test, the Up2Stream Mini was still power connected to the B&O power input and the ‘230v DC-to-5v AC’ power supply mentioned before. Playing the same Bob Dylan test music, there is NO noise/hiss on the headphones! So I assume the Up2Stream Mini is producing a clear signal, and maybe it can be excluded as problem source. Though in my setup I am not using the mini jack on the Up2Stream as audio out, but the 4-pin connector on the PCB. (Does that make a difference?)

Audio connection in my setup: Here’s some explanation how I have made the audio connection (See below picture as a reference). The internal Amp of the BeoLab 8000 has an audio-IN connector on the Amp PCB. The connector is named P4 and is a JST PH2.0 3-pin connector. Though the speaker is only used for Left or Right channel, there are 3 connections used, because the BeoLab uses an ‘Auto Stand-by’ switch that is listening to the audio signal coming in via the P4 connection. In practice it means that the 1st pin of this connector is used for listening; if audio comes in, the BeoLab amp is switched on (and switched off again when music ends). The 2nd pin is used for Left or Right audio-IN signal and the 3rd pin is the ground. So all three pins have to be used, otherwise the BeoLab ‘Auto Stand-by’ functionality will not work properly.

Audio cable: to connect the audio-OUT connector on the Up2Stream Mini PCB to the P4 audio-IN connector on the BeoLab 8000 Amp, I made a custom cable. I used the 4-pin connector cable that comes with the Up2Stream Mini, cut off the connector on one side, and also cut off wire nr. 4 (not used). And as shown in the above schematics, I soldered all the right connections together and shrink wrapped the soldering points.

Originally, my cable was about 30cm long and un-shielded. So, I thought maybe this cable is the ‘antenna’ picking up the disturbance and causing the noise/hiss. So, I replaced it by a shorter and shielded cable in the same connection-configuration: appr. 10cm, of which 8cm shielded. But also this change did not solve the noise/hiss.

Schematics BeoLab power unit and Amp:

For your reference, I have the BeoLab 8000 Service manual available. It includes the schematics for electronics. See this link.

Considerations:

I am not sure, but it came to my mind that certain capacitors might be a problem. After all, the BeoLab 8000 is still a fantastic active speaker, but also rather old. I have 2 units that are from the late 90’s and 2 units that are probably 10 to 15 years old. Though, I also noticed that the noise/hiss is the same on all 4 speakers.

[NWT.Stuff]

@KolfMAKER Thanks for detailed reply and all the drawings. Things are a clearer now. I have not had a noise problem BUT I have never used the AUDIO-OUT Connector !!! I have only used the 3.5mm Line Out Connector which I presume you used to carry out the test that @SimonB suggested (That was a good suggestion :))?

I will now Test the AUDIO-OUT Connector this week but what happens if you modify a cable to use the 3.5mm Jack to connect to the Beolab Input. That is essentially what I did last week to connect some Beolab 4 Speakers that I repaired to the Arylic S50Pro+ ?

Kind Regards

Kevin

[SimonB]

Hi,

I don’t know the B&O speaker, but it looks like your ground connection is incorrect: P4-4 is the GND and I suspect changing this will fix your problems.

By the way I’ve noticed is the diagram you are using for the Up2stream Mini V3 is the wrong one (V2 maybe?). Note on the V3 the line out connector (9) uses the same signal as the 3.5mm socket, but the pin assignment is: Rout, GND, Lout, GND. Whereas on the old it seems pin 4 was used for WPS reset. See here for the correct one: https://cdn.shopify.cn/s/files/1/0072/6899/1049/files/Up2Stream_Mini_V3.0_Manual-en.pdf?v=1591605095.

Hope that helps.

Simon.

[zpl1025]

If using the step down power directly from the amp board, there would be a loop ground. And you can unplug the jumper on board to cut the loop. Please have a try and see if noise gone.

[KolfMAKER]

Thanks Simon for your comments and suggestion!

Up2Stream
You are right. And yes I know in the older version pin 4 was for WPS. Thanks.

P4 connector
I just opened up one of the BeoLab speakers to check the P4 connector and pins.
If I look at the physical connector, P4 is a 3-pin connector with P4-1, P4-2 and P4-3 pins.
So I am a bit confused as the diagram shows P4-4 as ground. Do you get that?