Hi, how do you eliminate noise from USB output of Intel NUC (Roon ROCK) to DAC.
My setup is as below
Intel NUC <> Topping D90 <> Accuphase integrated amp
I have used iFi iPurifier 3 USB B input to D90 to further clean the hissing noise. This hissing noise can be heard when no music is playing. The noise is there even i turn down the amplifier volume knob.
What could be the culprit and root cause?
Do you mean with the volume turned down to zero?
How is the dac connected to the amp.
I turn on the amplifier with volume knob at - - dB .
Previously i am using XLR cable , now i am using RCA cable.
When I power down Intel NUC, the noise is gone.
I have tried to change different USB ports (4 of them), the noise still there. I even change my USB A - USB B cable, the noise still there. I am clueless.
It’s likely digital noise from the computer leaking into the DAC analogue outs.
My guess is the Topping isn’t galvanically isolated.
Switching to balanced / XLR ins/outs between the dac and amp ( if you have them) may fix it.
I had a similar issue using the unbalanced outputs on an RME DAC - an Intona usb isolator (the basic model in my case - was recommended by the founder of RME) fixed it. It provides the galvanic isolation.
You could also use a roon endpoint (eg Ropiee) - Roon recommend not connecting direct to your core for best sound quality (I assume for just this reason)
What are the speakers? Passive (I assume) or active?
@Auron_Lim, I had similar issues with direct USB core to DAC connection as @GregD.
I posted about it here and I can absolutely recommend the Intona to fix that issue, the basic model being absolutely sufficient for the task.
Thanks @GregD for your post. I am not sure if it’s D90 issue, another DAC Denafrip Aries II I tested also giving me the hiss sound.
Yes, I have tried to test with two sets of XLR/Balanced cables (Cardas and Mogami), the hiss sound is still there.
I agreed the culprit most likely is from the USB out of the Intel NUC .
I have another Roon Ready network media player Cambridge Audio CXN V2 connects to my Accuphase E280 via RCA, that’s clean without any hiss sound.
To avoid the Roon Core’s noise, I would probably connect digitally (USB A-B) from CXN V2 to my D90.
FYI, my music library is on external hard disk connected to one of the USB port of Intel NUC.
Hi Bill, it’s passive speaker, ATC SCM 11
The intona is well worth a try.
Certainly fixed my issue.
Let me try to connect from CXN V2 to D90 , if the hiss sound will be eliminated. Before I try Intona. Thanks again
Today, i connected my DAC D90 from CXN V2 instead direct from Intel NUC , the hissing sound still there, tested both RCA and XLR balanced cable .
Surprise me when i turn off my Intel NUC, i still cant get rid of this hissing sound , i even turn down the volume at amplifier … this shows that the problem is not from USB … more complicated issue… could it be my amplifier issue ? 
Need further diagnose…
If you have any clue or hints, appreciate to share to help me to solve this … though the hissing sound is noticeable when i listen at very close distance ~ 1 foot away
You’ve still got a lot of different components from different manufacturers connected there… is there some way to simplify the setup? It’s got to be either the D90 or the Accuphase amp, right?
Thanks @Torben_Rick for the clue on the ground/earth switch. I should have connected this USB input (Type B) at CXN V2 from Intel NUC USB ouput (Type A). Then using digital coaxial to D90 , bypass CXN V2 DAC. This may eliminate the hissing sound but the max audio frequency is 96kHz compared to 192kHz via USB
Question, is the 2nd USB from the left rear panel, local media means from external HDD/SSD? My current SSD (music library) is connected to Intel NUC for 24/7 ROON ARC.
Wonder if there is any USB output from CXN V2 to D90 ?
Yes Bill, CXN V2 is added later for more features and replaced Auralic Aries Mini, my intent of setup is to have flexibility on digital sources/DAC
digital USB output from Intel NUC to CXN V2, then analog ouput to Accuphase via RCA (internal DAC Wolfson from CXN V2)
digital USB ouput from Intel NUC to D90 DAC then analog output to Accuphase (XLR / RCA)
And you only get hissing on configuration #2?
Did no one pay attention to the above? People are making this more complicated than it is. The “hiss” has nothing to do with the NUC or DAC or USB. It is the inherent noise floor of the amplifier. Hearing the amplifier noise floor with your ear within a foot of the loudspeaker is not unusual.
AJ
Hi Andrew, thank you for your explanation.
Being OCD, i would think of a cleaner and quieter audio system when it’s idling without playing music. I have had Novaris power conditioner to ensure a proper clean isolated earth/ground system.
Another thing puzzle me from the specs of E280 as photo attached, the S/N ratio for balance is lower than unbalanced, is there an error ?
I hope sketch below can further explain my current audio devices setup.
Dual DAC (Denafrips Aries II or Topping D90) and Cambridge CXN V2 with Wolfson internal DAC fed from Intel NUC as Roon Core
If you pull all the connections out from the back of the amplifier (with it switched off) does it still his when powered up?
