Hissing Noise from USB ouput of Intel NUC

[MarcMarc]

I only hear that if I turn my Cxn V2 + CXA81 to max volume.

But I have to put my ear on the loudspeaker for that.

Maybe he needs a DC Blocker for his accuphase

[Auron_Lim]

Hi Ged, i did the test , removing all RCA interconnects from amplifier, there’s no more hissing sound, when i reinsert first pair RCA from any source, the hiss comes back.

[Auron_Lim]

@MarcMarc For my case, the hiss sound not governed by amplifier volume knob

[Auron_Lim]

@Marin_Weigel I am confused if the noise is coming from USB, I have the iFi purifier3 USB connect at USB Type B side before DAC , it supposed to eliminate the noise , isn’t it?

Wonder if Intona really solve my issue , furthermore it’s not cheap .

[ged_hickman1]

How about just the lead without any device behind it.

[Auron_Lim]

I don’t understand Ged. What do you mean ?

[ged_hickman1]

Just plug the RCA leads into the amp by themselves with no equipment attached. See if it’s the input itself that is hissing.

[Auron_Lim]

Thanks. There’s no hissing when I connect RCA to amplifier only without connecting to sources.

[312Elements ("The absence of evidence is not evidence of absence.")]

From what I gathered from your posts, when there are no RCA’s plugged into the amp then there is no noise.

Are all of the electrical devices in the chain plugged into the same outlet (shared ground). That would be ideal for testing purposes assuming that you’re not overloading the outlet.

My personal workflow for solving this problem would be unplug and disconnect everything and then add one unit back in at a time. Disconnecting everything is important here.

There is one or more devices in your signal chain not behaving properly. I’m guessing it’s purely a grounding issue and this will point you to the source.

As you reassemble I’d test everything as simply as you can. For example NUC>D90>Amp then turn off the D90 and disconnect and try NUC>Ares 2>Amp. It might not be until you plug both dacs in simultaneously that you notice the noise.

As for solving the problem, in the past I’ve had to physically ground devices together by using a piece of wire with one of those little circle rings terminators attached to both sides and removing a random chassis screw from each device and grounding them together that way.

[ged_hickman1]

@312Elements

As for solving the problem, in the past I’ve had to physically ground devices together by using a piece of wire with one of those little circle rings terminators attached to both sides and removing a random chassis screw from each device and grounding them together that way.

Hence the grounding posts on susceptible equipment such as turntables, phono amps etc.

[Auron_Lim]

Thanks @312Elements for your guidance on troubleshooting. Yes, my audio equipment are connected from two wall receptacles (same circuit) with multi-gang Novaris power conditioner and Belkin multi-gang sockets respectively. No overloading as not all equipment are turn on at same time, the most power consumed is Accuphase Amp.

One of the potentianl hazard could be the grouding of 500VA step down transfomer 230V/110V for 110V Sony CD player (i turned off the stepdown
TX most of time but it’s plugged to the socket)

Yeah, I will do a trouble shooting as per your advise to disconnect all then add on one by one.

[312Elements ("The absence of evidence is not evidence of absence.")]

I’m definitely not an electrician so be sure to do your homework but maybe remove those devices from the outlets and assorted interconnects to eliminate them as the source of the problem.

[Marin_Weigel (Bram Stoker's Cappuccino)]

@Auron_Lim

… the iFi purifier3 USB connect at USB Type B side before DAC , it supposed to eliminate the noise , isn’t it?
…

Don’t l believe it’s doing what you think, and it costs some ~150€, so not cheap either.

Seems that actually the iDefender3 is supposedly galvanically isolating USB in to out.

I’ve no experience with these ifi devices and actually detest the audiophile buzzword frenzy in their marketing prose - never a good sign of solid engineering, in my book.

The Intona unit on the other hand was originally designed for medical devices, where special AC power insulation of equipment, as well as galvanic isolation of equipment interconnections is compulsory.

This Intona unit does what it says in it’s specifications, no techno-babble to be found.

And if you’ve really got conducted noise being fed from the USB source, it absolutely gets rid of it, no “100x noise reduction” ifi blah blah… and don’t get me started to comment on their reclocking and jitter hogwash!

But back to your case, it seems you need to test your setup in a logical manner, much as @312Elements recommends, as your reports are somewhat contradictory, as well as you forgot to mention all interconnected componentry, making it impossible to do any senseful remote troubleshooting (got a TV hooked up as well, maybe?).

So, remove all power conditioning and other accessory devices and outlets.
Use a regular power strip.
Plug in your integrated, nothing else connected but the speakers.
Power up with volume at zero - any noise, even close up to tweeters?
Carefully ramp volume and observe noise.
Return volume to zero.
Hook up next device up the chain into same power strip, retest noise as above.

And so forth - you’ve got the drill?!

Report back then…

[Auron_Lim]

@312Elements @Marin_Weigel
After disconnecting/unplugging all devices, then i started one by one , i then found out the hissing sound generated from PSU to Intel NUC (230V/19V AC/DC)

The next but very little hiss is D90
There no hiss on CXN V2, TV, stepdown transformer which I re-connect first.

I google further on intel nuc and found this article

Nasty ground loop between my NUC8i7BEH and audio interface

Having read the above article, some said removing the Intel NUC power adapter ground/earth will “solve” the issue, should i remove earth wire on 3-pin plug, probably i need to replace with new plugtop since the original plugtop is screwless

[AceRimmer (Smoke me a kipper, I'll be back for breakfast!)]

If it’s truly this they make a ground lift “cheater plug “ which would likely be the safest way to test this.
At least they do here in the USA, not so sure for EU style plugs.
Although safe is all relative in this method….

[Fernando_Pereira]

Suggestion: try a suitable medical spec SMPS, such as https://www.digikey.com/en/products/detail/mean-well-usa-inc./GST90A19-P1M/7703719

[Auron_Lim]

For the safety products, most products shall be earthed/ground, including some with frame earthed. There’s our local electrical regulatory recommendation

[Auron_Lim]

Great and thanks mates. That’s I am searching for , it’s affordable and not so “audiophile” snake oil grade LPSU.

Manage to find in our local online store too

http://shorturl.at/cdFLP

I have placed an order

[312Elements ("The absence of evidence is not evidence of absence.")]

Congrats on finding the problem! Keep us posted on whether the proposed solution solves the problem.I’m sure it could help others too.

[Auron_Lim]

Thanks @312Elements for your guidance , will report when I get the new power adapter.

Hopefully it will resolve the annoying hiss issue. Finger crossed