The exception that proves there is a rule. 
Iâm a tube person myself. I use PrimaLuna preamp & amp. You?
Doesnât this suggest the AVR has â â â â â â isolation on its inputs. Changing to an LPSU on the NUC is unlikely to resolve this
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Iâm a âwhatever sounds convincingly realâ person, myself. Which is why I also have a good solid state system (Naim Supernait 3 + HiCap DR. Also owned Benchmark LA4 + dual bridged AHB2âs as monoblocks).
Tube setup is Line Magnetic LM512CA preamp and LM503PA 845 SET monoblocks (essentially, updated/upgraded WE91bâs that drive the grids of 845 output tubes).
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If Marantz 7013 has ****** isolation on the inputs, I am not sure what class of AVRs would take care of that. I donât think a LPSU will also take care of the noise either. Could be something else coming from the board. But, this type of noise is typically dirty power.
Most SMPS used with audio gear donât have a ground connection, and are exceptionally good at filtering high frequency noise. Galvanic isolationâoptical, radio transmitter, etc.âprevents noise entering the DAC. Theoretically, a linear power supply is more likely to introduce a ground loop.
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Yes, if you mean no connection between PE (AC line protective earth) and DC output ground.
Theyâre usually designed as class II devices, being doubly isolated.
But their AC input does absolutely need a three wire connection with PE for the obligatory internal line filter to properly attenuate switching artifacts going back into the AC supply lines - never use a cheater plug/cable on those, youâll loose rather than gain something here!
Always depends:
- If designed as class I device, yes, since chassis, PE and DC output ground connected - possible ground loop.
- If designed as class II device, no, see SMPS case above.
You can always check the labeling for a power supplyâs classification
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More likely to be EMI coming from the cpu and various chipsets onboard. Very unlikely to be power supply related. You could get an hdmi over Ethernet converter and see if it isolates better from the noise
My system has two TT (each with its own phono stage), SET monoblocks etc. Digital is Roon Nucleus+, Pi4, Holo May. The only âtweakingâ is to the digital source side of my system, just trying to get it to sound halfway involving and enjoyable.
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<JOKE/
Just add some audible pink noise, read posts of others of how to force Roon to produce random pop and click sounds, and youâll find your digital audio nirvanaâŚ
/JOKE>
You should post here. Everyone likes HiFi porn.
Touche! 
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Done. Not Hi-Fi porn but I think it is a pretty solid setup. It is in the vinyl rig thread since it has turntables.
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If you are looking at replacing the standard SMPS brick in an effort to improve the sound of the Nucleus / overall system, donât bother - it does a perfectly adequate job of supplying a stable voltage and adequate current to the NUC. Yes, it generates an element of RFI because of its design and the unscreened plastic case, but thatâs only of any issue if the PSU is sitting in a bunch of cabling at the back of your system, and only then if its cable carrying analogue data which is susceptible to RFI. Digital data is not, unless the RFI is so bad it causes packet loss, but this does not happen! Think of it this way - banks have been using enterprise network switches since Noah got his feet wet. Those switches invariably have multiple redundant SMPS supplies in them. If there was even the remote chance of data corruption / loss, those PSUâs would never be used. If you are so inclined, familiarise yourself with the 802.x Ethernet protocol and how data is actually transferred. While youâre at it, have a ganders at the ISO model and everything will become clear. Its hardly light bedtime reading, but it will, assuming you absorb it sufficiently, allow you to understand why changing your computers PSU, dabbling with exotic network cables, or dropping money on a so called âaudiophile network switchâ is simply not necessary. Transmitted data either arrives at its destination intact, or it doesnât. Its a âyes/Noâ thing and unlike analogue, there are no in-between options. Unfortunately audiophile equipment manufacturers and reviewers would have you believe otherwiseâŚ
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Iâm pretty sure nobody has suggested that data integrity is the issue with SMPS use.
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No, people just make claims of ânoiseâ affecting the resolution of their âhigh-endâ gear.
I made a -120dBFS 1 kHz 50% square wave test track to test out my system after a (now suspended) user claimed my poor quality streamer (RPi4B running RoPieee) was compromising my DAC output and polluting it with noise. I can pull the test tone into audibility. So far, no one else who has tried it has been able to.
My system has a lot of very clean gain, exceptionally low noise and very low distortion. I have standard, enterprise grade network gear, with steel chassis (which BTW are better at minimising RFI than aluminium), bog standard Cat6 U/UTP cables, no fancy tweaks. The stuff banded around about noise from PSUs, ethernet etc. is nonsense. Pure audiophilia nervosa.
Knock yourself out.
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Probably not data integrity but⌠I will mention here that the USB Audio protocol (which is NOT the same protocol used when you read/write to a USB hard drive!!!) is NOT error correcting, so communication between host and DAC is not guaranteed to be error free. If you had a lot of electrical noise, it is in principle possible that the data could be compromised.
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You are right that audio data is not guaranteed error-free. However, if there were errors, those would manifest as clicks and pops, so they would be objectionable. If electrical noise was that high as to induce errors across a 6ft-or-so USB cable, then transferring data from a USB hard drive would also be affected - in the sense that many packets would have to be retransmitted and the data rate would be visibly reduced, and that would also be objectionable. What are the chances of that happening in a home listening environment?
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Please quote your source, since I think this is incorrect and refers to isosynchronous transfer.
My understanding is that USB audio (UAC2) is asyncronous, i.e., the PC sends bit-perfect data, and the DAC controls the clock. Error detection is provided by CRC. That is, errors are detected, dropped, and resent.
Yes, thatâs right.
No, the USB Audio protocol, that part of it which involves sending the actual music frames, is indeed checksummed, so errors can be detected, but thereâs no resend protocol. So, only detected and dropped.
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To be more specific, âasynchronousâ is one of the synchronization mechanisms used with isochronous USB mode.