Good morning,
I' m interested in building a dedicated PC for only transport purposes, to play files and send via USB to an external (high-end) dac.
I looked to many implementations, with expensive LPS, 2 or 3 cases for power supply.....BUT at the end every motherboard has onboard VRM for low voltage regulations 1,8V, 3,3V, 5,V...
and these regulators are 100% switching
LPS to power the mobo, the cpu, the hard disk is completely useless, if the voltage regulators onboard on the MOBO produce for example 100mV ripple!
my question is:
How to choose a MOBO in order to have the best VRM and the lowest ripple?
there was a past topic now closed:
I ask for example @skibum @geraldfryjr @marce if they can help, thanks
I' m interested in building a dedicated PC for only transport purposes, to play files and send via USB to an external (high-end) dac.
I looked to many implementations, with expensive LPS, 2 or 3 cases for power supply.....BUT at the end every motherboard has onboard VRM for low voltage regulations 1,8V, 3,3V, 5,V...
and these regulators are 100% switching
LPS to power the mobo, the cpu, the hard disk is completely useless, if the voltage regulators onboard on the MOBO produce for example 100mV ripple!
my question is:
How to choose a MOBO in order to have the best VRM and the lowest ripple?
there was a past topic now closed:
I ask for example @skibum @geraldfryjr @marce if they can help, thanks
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A separate audio player/transport with internal linear PSU ticks many boxes. Lacks also the for audio non essential stuff in a pc like Windows and a graphics card (EMI transmitter).
Sometimes things can be simple.
Sometimes things can be simple.
What do you mean "separate audio player with internal linear PSU"? Can you make some example?
I would like to use a PC because I would use PureAsioPlayer software.
It is a concept. They do not waste power, are small, do not make useless noise, need no noisy fans, no Windows/Linux with regular required user intervention, no configuration, no noisy ATX SMPS PSU, are not dust magnets, have no overkill Intel/AMD CPU with their EMI, no graphics card with EMI, no sound card, no harddisk, no virus, no OS updates, no logging in, no popups screens, no driver trouble, no monitor, no keyboard, no mouse. PC Audio is self inflicted trouble. Like swimming in a gutter trying to find potable water.
Google for WiiM Ultra, Eversolo DMP-A6.
Google for WiiM Ultra, Eversolo DMP-A6.
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I would not use audio non essential stuff anyway, they would be disabilitated...
I would go through USB output to an external DAC
Maybe via a dedicated USB PCI express card such as JCAT Femto.
I don't need a streamer.
Only playing local files.
I don't want to be connected to internet or any network.
Audio players are designed for and dedicated to audio and therefor they don't have all the self inflicted trouble pc's bring. Non existing trouble does not need to be solved. Local files and also no network are no issue but careful selection is necessary as many are streamers dependent on internet/providers. For operation either an IR remote controller or a smart phone/tablet via wireless or bluetooth is necessary. Internet is not a necessity.
Using several LPS to power a pc is plain silly. These are crammed with onboard switchers and ultra high frequency parts and memory/data busses all conflicting with the idea of having quality clean signals AKA the main goal in quality audio.
BTW at least one of the ones I pointed at is NOT a streamer. I have the Eversolo and use it for local files. There exists an IR remote controller for it too. Had several others too that lacked Internet dependence and had similarity to cassette players, CD players etc. That devices may have wireless or ethernet (just like your pc has) does not mean you are forced to use that. It can be handy to transfer data though. Please get your facts straight. The "flexibility" of pc's is exactly their burden in audio.
Using several LPS to power a pc is plain silly. These are crammed with onboard switchers and ultra high frequency parts and memory/data busses all conflicting with the idea of having quality clean signals AKA the main goal in quality audio.
BTW at least one of the ones I pointed at is NOT a streamer. I have the Eversolo and use it for local files. There exists an IR remote controller for it too. Had several others too that lacked Internet dependence and had similarity to cassette players, CD players etc. That devices may have wireless or ethernet (just like your pc has) does not mean you are forced to use that. It can be handy to transfer data though. Please get your facts straight. The "flexibility" of pc's is exactly their burden in audio.
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Thanks for the input, for now I keep trying to understand if there are very low ripple MOBO.
I would use Pure Asio Player software, and this needs a PC.
I would use Pure Asio Player software, and this needs a PC.
USB output is digital and carries no clock in case of a decent UAC2 async DAC. But it can cause nasty ground loop effects as the interface involves a ground connection. That is easily fixed with a USB highspeed isolator for 35EUR. Of course it assumes the DAC has an external PSU (which is always the case of a decent DAC). Therefore absolutely no logical reason to pay a nonsense price of 500EUR for an add-on PCI-e/USB adapter which differs from a standard 10EUR adapter only in some voltage supply regulator and a by-passable filter - both of which have no effect if the isolator and externally-powered DAC are used.
No reason to power the countless onboard switched-mode regulators with a linear PSU, especially if using a USB with isolator.
Virtually all boards, including low-power SBCs used in dedicated streamers, have onboard switched-mode regulators.
Just a note - if you need a dedicated windows PC to run your favourite player software, there are very inexpensive refurbished thin client PCs from good brands, high-quality builds, fully passive. Right now I am playing with HP T640 https://www.parkytowers.me.uk/thin/hp/t640/ for some 60EUR incl. shipping, the device accepts 2 x 32GB DDR4 RAM ("only" 32GB in mine), fast NVMe drives (mine has 1TB), quality PSU, very nice design, impossible to tell it's refurbished.
No reason to power the countless onboard switched-mode regulators with a linear PSU, especially if using a USB with isolator.
Virtually all boards, including low-power SBCs used in dedicated streamers, have onboard switched-mode regulators.
Just a note - if you need a dedicated windows PC to run your favourite player software, there are very inexpensive refurbished thin client PCs from good brands, high-quality builds, fully passive. Right now I am playing with HP T640 https://www.parkytowers.me.uk/thin/hp/t640/ for some 60EUR incl. shipping, the device accepts 2 x 32GB DDR4 RAM ("only" 32GB in mine), fast NVMe drives (mine has 1TB), quality PSU, very nice design, impossible to tell it's refurbished.
The trick is to choose a platform that could give you the ability to undervolt the CPU (NOS), but also to allow for full CPU boost operation in case you decide to use HQPlayer Pro and its pretty good DSD modulators (with the high-end DAC via USB) that are extremely demanding. So, using full-size motherboards is probably not a good idea. Using the desktop PC SMPS is a terrible idea. I'd look at NUC11/12/13 and similar platforms.
Then comes the OS... tiny 10 is good, but there's no reason to struggle with necessary add-ons; try an Enterprise WIN LTSC that already has everything stripped down, BUT it still contains the required services to correctly run the HQPLayer Pro, AND it (Enterprise version of OS) deploys only the necessary updates by default. The number of background services is simply perfect. No need to struggle to remove/disable them manually... However, you could still remove/stop services that you know will not be needed. The guaranteed OS/virus definition support goes beyond 2030.
Next would be the choice of RAM and m2 SSD... the single rank RAM sticks (used in pairs to allow for dual channel CPU access) will use very little power. So would SSDs like SK Hynix P31 and Samsung PM981a (similar power draws in all power states to SK Hynix, but much cheaper). I did a comparison between identical OS installs, on 1TB 980 Pro and 1TB PM981a... and the difference was simply mind-blowing. The PM981a provided much better sound, relaxed... easier to listen to. The speed difference (vs 980 Pro) is not enough to prevent me from running nice DSD modulators still, with HQPlayer Pro. Re RAM, dual-rank RAM sticks will be faster, but will use much more power.
Then comes the power supply... despite the fact that motherboards use switching regulators, nothing is stopping you from trying a good quality linear power supply with very low noise, great load regulation, low output impedance into MHz range... AND most importantly - no HF rubbish is being sent back into mains power strip where the rest of your audio gear is plugged in.
If you are a gamer, then yes... high-switching CPU voltages/huge TPDs is a must, dual-rank RAM sticks as well, fastest SSDs you can get.... kW SMPS... but that will make a terrible high-end digital audio streaming platform...
The add-on PCIe JCAT Femto will also require additional power from the system... more switching noise... AND will prevent you from running very high PCM oversampling rates (1.536MHz.. if you are into that kind of stuff)... unless they fixed it...
Wouldn’t a simple S/PDIF board with an optical TOSLINK output be enough to isolate the DAC from the noisy MOBO?
Well, ... the saying "extraordinary claims require extraordinary evidence" would seem to apply here ...
Please any more info on that? The card is a standard USB controller which does not care what information the bits running through it actually represent. If the card had problems (just guessing) with full bandwidth of highspeed or superspeed, then it's a buggy product to start with. I have never heard of an onboard USB controller not keeping up with USB bandwidth it was designed for.
I don't understand why....they also have the possibility the be externally powered.
So they would reduce noise...
I think this is very much an impossible compromise: you either want a lowish power, none/text mode/minimal video, with ideally linearly regulated MB rails or you want a water cooled, GPU-ed power monster for HQPlayer.
Very different customers for either setup, with the HQPlayer user clearly having a DSD dac, so noise already a part of the package.
Btw the low power option does not necessarily exclude HQPlayer if one is prepared to go the offline route.
Yes. OTOH it's a PCI-e device which assumes a regular PC format. Those are very prone to ground loop noise on which this card has no effect (the PC ground is still used). My 2 cents a ground loop noise is more likely to affect the performance of the chain than USB-port 5V voltage, especially with a decent DAC with external power supply.
This conclusion isn't necessarily the case. In my understanding the reason for a LPS is to eliminate the common-mode noise aggressor present in the mains-fed SMPSU. Simply put - the difference between the mains-fed SMPSU and those motherboard buck regulators is the latter are not referenced to mains neutral (and therefore to mains earth). The ripple noise on their output is only of consequence if it becomes imposed on the audio signal somehow and that seems unlikely as the current loops the noise travels around are small ones.
Thats what I do. One outlet power strip is "digital only" , my right table is my 2 amps , preamp , Topping dac , super-regulators.
Optical TOSlink is the only connection between my right and left tables.
My analog table has (below) connected to a Leviton rack strip with lots of MOV's in parallel.
I see NO "fuzz" on my analog side.
My Seasonic 750W PS (digital side) isn't too bad , but I can see it on my scope.
Cheap 5V phone chargers and my 7A LED SMPS are horrible.
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IMO it would be outdated (these days) to assume switching PSUs are bad and linear ones are good. There are very good and bad examples of both. And small amounts of ripple or noise should make no difference in a competently designed digital PC.
The challenge comes if you want to run analogue stuff off the PSU, such as an internal sound card or DAC. This is also challenging for other sources of electromagnetic interference, since PCs aren't an ideal environment in that respect either. One can be lucky, but after years of trying, my overwhelming conclusion is to avoid such things and just go with external DACs, preferably with their own PSU. If you choose a mini PC or laptop without an earthed supply it can also help to avoid ground loops in some cases.
The challenge comes if you want to run analogue stuff off the PSU, such as an internal sound card or DAC. This is also challenging for other sources of electromagnetic interference, since PCs aren't an ideal environment in that respect either. One can be lucky, but after years of trying, my overwhelming conclusion is to avoid such things and just go with external DACs, preferably with their own PSU. If you choose a mini PC or laptop without an earthed supply it can also help to avoid ground loops in some cases.
Just out of interest, do you have an example of a switching supply where CM noise has been successfully tamed?
Not recently, unfortunately. I gave up on that approach quite a while ago, partly because such specifications weren't commonly quoted in the PC world, which made upgrading/replacement a headache. But mainly because there were so many other sources of electrical/electromagnetic noise in my PCs that going external for the analogue stages was a much more complete answer. Prior to that even daft things could occur, like 'hearing' on-screen activity - even down to the mouse cursor moving.