RF noise with usb

[hixy]

My pc consists of an AB350m motherboard with a Ryzen 5.I'm trying to connect either ha2 or AK junior via USB then line out to a Little Dot Mk 2.Inbetween songs the rf noise is really bad any ideas on how I get around this also when going from USB to Phiree optical converter to my Bushmaster DAC I get no interference at all,The reason I want to use the other two dacs is because they do dsd.

Mick

 

[Yomanze]

Have you tried different USB ports, specifically not a USB3 (Blue) one?

 

[hixy]

Yes, I've tried that no joy. Maybe a dedicated sound card would be an option.

 

[Jim Audiomisc]

My pc consists of an AB350m motherboard with a Ryzen 5.I'm trying to connect either ha2 or AK junior via USB then line out to a Little Dot Mk 2.Inbetween songs the rf noise is really bad any ideas on how I get around this also when going from USB to Phiree optical converter to my Bushmaster DAC I get no interference at all,The reason I want to use the other two dacs is because they do dsd.

Mick

What do you mean by "rf noise" and "interference"? Do you mean you hear crackling noises, or what?...

 

[hixy]

what I mean is buzzing noises sounds like rf noise. you can hear the pc through the dac.

 

[Rick_F]

I've never experienced any interference or noise from a USB connection, but just maybe worth trying something like an Audioquest Jitterbug.

https://www.audioquest.com/jitterbu...ower-noise-filter/usb-data-power-noise-filter

If you are able to get inside the pc I'd check all connections and see if any cables are close to power leads & anything else that can create noise.

 

[Whatsisnaim]

Audioquest Jitterbug.

That might mitigate the problem, but with audible hum, I would take a ‘prevention is better than cure’ approach and try to identify/replace the offending component.

 

[Rick_F]

That might mitigate the problem, but with audible hum, I would take a ‘prevention is better than cure’ approach and try to identify/replace the offending component.

That's why I also mentioned trying to get inside and have a look for any cables issues.

 

[Jim Audiomisc]

what I mean is buzzing noises sounds like rf noise. you can hear the pc through the dac.

That makes me suspect crap on the 5v USB line. But it may be audio-band crap, not RF.

How is the DAC powered? Afraid I don't know anything about the models you specify.

Some years ago I checked out various external DACs, and hubs. Some DACs picked up power line noise much more than others. A quick test if they are USB powered is to try going via an added USB hub that provides its own power. The snag is that the USB hubs also vary in how much garbage *they* put onto their external power feed.

FWIW when I tested, the type CPC sell as CS16383 had the lowest line noise. But there is always a risk someone changes a design or chooses a different 'wall wart' and changed the behaviour.

 

[hixy]

Unfortunately, the dacs are powered by the micro USB cable which plugs into the pc.

 

[Jim Audiomisc]

Unfortunately, the dacs are powered by the micro USB cable which plugs into the pc.

That should mean you can make the connection via an additional hub with its own power supply. Given an appropriate external hub, the DAC then will draw its power from the hub's PSU not the 'pc'. In my experence this can make a measurable difference in some cases.

 

[hixy]

Thank you Jim

 

[Jim Audiomisc]

Note that not all external hubs are 'created equal'. Some behave weirdly, others well. Minefield. I recently compared four different types. One had a worrying flaw in that it put 5v *back up to the source*. So would light up the leds on a small computer I use when the computer psu was off. Risk of an electronic clash that could do damage! Most aren't that seriously flawed, but performance in terms of reliable working and power line garbage vary from one design to another.

 

[cctaylor]

The problem I had was that USB power supply was had noise from the video display on it. The cheapo USB speakers I was using put this out and was annoying. Changes on screen such as scrolling were audible.

I was lucky enough to pick up on of last sets of QSB USB powered speakers. They cured the problem with the bonus of only needing a single USB connection.

On reflection it is possible that the soundcard was picking up the noise.

 

[hixy]

Jim I was looking at an Anker USB hub,what do you think.Which one do you use.

 

[Jim Audiomisc]

Jim I was looking at an Anker USB hub,what do you think.Which one do you use.

I tend to use the one CPC sell as part number CS16383. Of the ones I've tested, this seems the most reliable and gives the lowest rail noise when powering audio devices. So I'd suggest trying that. Note, though, that makers sometimes change parts or their 'wall warts' without any warning, so I can never be certain the next example will be the same as previous ones. That said, I now have five of the above and they all seem fine. They are all USB1/2 *not* USB3.

Also, you may find that simply changing the wall wart PSU helps. So in the end this seems to come down to experiment - suck and see. I don't know of any hubs which come with specs for things like rail noise.

No idea about the 'Anker' one you mention as I don't think I have ever used one. Can you point me to a URL or reference for it?

 

[Jim Audiomisc]

I just did a quick websearch (DuckDuckGo) for anker hubs. The first thing I found was that their webpages won't render readably with a light non-js browser. Which doesn't fill me with confidence.

Looking at reports on other pages I get the impression their big point is high power available and USB3.

I can't say about the 'Anker' models specifically. But the two USB3 high 'charging'/'demand' hubs I tried from CPC recentely were both a PITA. They refused to work with various ports on my machines, and one produced the 'back up the line' phantom power effect which is, frankly, dangerous. They *aren't* Anker branded, though, so all that may be irrelevant. But the questions you need to check are - Do you really need high power provision? Do you need USB3 simply for audio transfers? Here USB2 hubs work fine on all my machines for audio. This includes powering items like the Focusrite 2i2 that is an ADC as well as a DAC.

 

[Thinkfloyd]

Here's a left field question for you - do you have any touch sensitive lamps plugged in to the same circuit? I've seen this before when a touch lamp is plugged in in the same room. Basically the touch works be creating a leak into the ground and it'll cause this kind of noise.