I have integrated an Up2stream Mini + DAC board into + Mean Well PS-05-5 power supply into an AKAI-AA-1020 receiver. I wired the DAC output to the AKAI’s AUX input.
I have a problem with noise which is clearly coming from the antenna. It is extremely sensitive to placement. I hear a lot of crackling when the antenna is near other cables.
What I understand: The location can very well effect the signal strength. When I put it on some metal the signal degrades from 100% to 37%.
What I do not understand: The crackling seems to be a problem of the board design. It assume that the Wifi antenna connector on the board is so close to some L/R signal pins that it can disturb the sound.
I also noticed that the antenna has been glued. Is this a workaround for this problem.
In the pictures, you see my current workaround of antenna placement. It is sticked on a cable tie positioned away from metal and cables. This way, I do not have any crackling. However, it feels like a highly vulnerable system. I am thinking of using an external antenna.
Hi Bidjan,
I haven’t seen an antenna connector glued before, it arrived like that?
I would recommend an external antenna as the amplifier’s chassis will degrade your wifi signal.
I might ask Arylic to supply shorter I2S cables too, as these often pickup local noise. Some forum members have resorted to wrapping this cable with aluminium foil.
Cheers,
Steve
Hi Steve, we received some feedback for weak signal, and the root cause is antenna loosed. So we made this change. User could clear it if he want to connect another antenna, not a problem I think. And for user who want to use the existing FPC one, he could be away from some unwanted connector issue.
Besides the material at the antenna connector, maybe an observation to add …
I have never had any problem with the standard antenna (the strip with the glue layer). Only …
If the antenna is surrounded by metal, it will not work. I have experienced many times that if the WiFi signal received by the Up2Stream is not strong enough, the speaker can produce crackling noise.
My advise would be to work with a rod antenna and place it on the back plate of your AKAI receiver. @SimonB has done this several times. Here you can find one of his posts with an example of implementing a Mini with a rod antenna in a Hitachi receiver.
Pay attention to the picture below (or the 5th picture in his post) that shows the rod antenna mount.
In his 2nd picture you see the inside of the Hitachi receiver, the position of the Mini, and the WiFi antenna cable going to the rod antenna on the back plate.
Thanks a lot. Very helpful and I think I will go that route. I have already ordered external antennas. I assume that their cables might be to short. Can I simply cut and extend the antenna cable or is there anything more than a single wire?
Hi Bidjan,
Not that easy, it’s a screened cable, if you search for a Small SMA connector to UFL(IPX) screened patch lead, you will find that you can purchase different lengths to suit your application.
Steve
In my experience, the FPC antenna placement matters a lot. Best to place it as far from any electronics as possible. You’ll need to experiment to see which placement gives you the least crackling sound.
In the AKAI receiver with the Mini streamer, I could solve with issue with an external antenna. Currently, I am working with the Upstream Amp. I upcycled an old Technics Tuner with it and it runs in a 2.1 configuration with an active subwoofer and I also use an external Wifi antenna. Initially, I had some ground noise from the sub which went away when I used an additional ground cable (GND of sub RCA out to electrical GND/Technics housing).
Now, I noticed that the subwoofer still has some noise and did some checks. The noise has to do with the Wifi antenna. When I took it off, I had dramatically loud noise from the subwoofer. How can a Wifi antenna NOT connected to the amp cause that noise? Should the Wifi antenna’s GND not be connected to the electrical GND? I am confused and have the feeling that the Wifi antenna connectors of the Arylic streamers are troublesome. Any ideas or suggestions?
Hi Bidjan,
So the noise is only through the subwoofer? You could try the antenna in other locations on the chassis, ground it with a length of wire and move it and see if the problem persists or maybe try a ferrite suppression core around your sub cable.
Steve
yes - the noise is only with the subwoofer. I had no time to look at the details yet, but I have a suspicion. I assume that the amp is (only) grounded via the antenna (which has contact with the metal housing). At least, that could explain that there is very loud noise when the antenna is disconnected from the board. When I have the time, I will experiment with an extra ground cable from the amp to the housing. I noticed that the amp is only screwed onto a wooden plate. Usually, the screws would make contact with the metal housing. I assume that every srew hole of the amp provides GND, right.
