I replaced a wall wart with a linear power supply

[AlainGr]

I will do some reading. Thanks for the link and contribution

Regards,

Alain

[PeterSt]

Sorry PeterSt, but I have another question for you, and please forgive me if you have answered this elsewhere.

Are you able to offer any insight into why a linear psu feeding a pc may improve sound quality in a dac?  I have been asking this question on another forum and nobody there seems to be able to provide an answer other than "your dac is broken" or "it just does" (neither answers are particularly helpful but they are insightful).

By the way Peter, I only stumbled across your NOS1 project a few days ago but it seems very forward thinking to me.  I would love to hear one. 

Hey Anthony - warm welcome here !

Well, as you will have seen, I hasted to say that I have no real judgement on that to begin with.

But which all doesn't tell me really that this helps SQ. I just don't know. It can for sure, but don't blame me because of some enthusiastic Wow when it does not.

So how to improve upon a "your DAC is broken" etc. ?
Well, the response can't be simple and I'm afraid it will be too brief and will show that I really don't know.

Let's take a USB (asynchronous) connection;
This won't show any switching PSU sh*t that I have seen. It will show its own transfer-current noise (tough to solve in general) but that's it. So, no linear PSU will help there.

Notice though that I assume a good grounding scheme for which no rules exist. Have that wrong, and you may be hearing your mouse through the speakers. But, through what connection that goes ?

Now we have a random switching supply (could be from a phone charger, could be from the PC). Still no problems in the USB link. BUT, problems on the mains. So, all sorts of nasty things can be seen there.
Do we see this in the DAC ? again, with proper grounding we do not. And I mean overall "house" grounding around the stereo.

And this is about it; when all is grounded correctly, no problems will be seen anywhere. Still this sh*t is on the mains. But now the point : you won't be able to see this sh*t unless you had an analyser for the job ($$$$).
And NOW avoiding the problem in the first place is crucial.
So yes, it can help. But no, it won't help me. Well, that is what I think, because influences need to be very minimal only to imply SQ changes, and they will be in the area of unmeasurable. So, same like XXHighEnd influences SQ - which can not be measured as well.

So, YMMV ?
Peter


PS: For fun look here : Buzzing noise at plauback
The culprit (as known by now) : A too old tube in some amp. Do we get that ? ok, I don't.

[PeterSt]

One question for PeterSt.  Do you think that a common mode filter between the PC and NOS1 will help at all?  I am not familiar with the USB input on the NOS1, but the maker of this filter has posted jitter measurements here. (see post #9)

Assuming Async USB, it can't. Well, it can, but you'd be filtering in-band audio.
USB noise expresses at 8KHz, 16KHz (and 24KHz and beyond) and nothing is able to filter it out. Smart grounding schemes do though (applied in the NOS1).

Note that USB noise is about the current needed to get in (!) the packets of data.
This is also how no glass connection will help that (and how an Adnaco can make it worse by first a poor PSU and next more current needed to get the job done).

Peter

[acg]

Thanks for your time Peter.

Note that USB noise is about the current needed to get in (!) the packets of data.
This is also how no glass connection will help that (and how an Adnaco can make it worse by first a poor PSU and next more current needed to get the job done).

I have learned something today!!  Can you tell me where in the computer the packets are formed?  Is it in the host controller (EHCI)?  If we were to use a PCIe to USB card, for example, would that shift the location that the packets are formed to the PCIe card itself?  Could this be why I hear a difference with my modded usb card that isolates itself from the pc with a transformer and relies on external power?  I have also noticed a _huge_ difference in sound with just a normal $15 PCIe card in an busy Xeon based workstation: the sound went from 'crackles and pops' to actually listenable!!  I put that one down to better power supply to the usb controller, but of course I may be wrong.

So many questions for a newbie. 

Anthony

[Robert]

Well I replaced a switched mode power supply for a linear one on my M2tech Hiface Evo and whamo what a difference in sound. Vast in fact. POWER SUPPLY IS EVERYTHING never changes!!!!

[PeterSt]

I have learned something today!!  Can you tell me where in the computer the packets are formed?

I don't know, but let's say it is in that particular hardware.
Two reasons though why I regards this as less important :

1. Implied software activity is I think more important (think Driver hence OS);
2. The sh*t happens at the other side merely.

So, in the DAC all sh*t happens, or that is where all comes together if you like. In-PC as much noise and as many spikes can happen what you want - it is about that arriving in the DAC what is the only place where it can be harmful. And indeed, the path through the mains is the most complicated (and 100% USB related), let alone the radiation coming through air where you think you could kill it (like an off line UPS could imply that).

USB2 vs USB3 is also such a thing. We are all sure that USB3 sounds better (for the NOS1 at least). Still my own reasoning can only go in the other direction, and it should sound worse. Well, with all the tweaks and things applied the last couple of years, maybe someone must try USB2 again.

This whole thing is so super complex that at least I may never find the real merits of it all.
But hey, aren't we with many more ?
*That* is our chance ...

Peter

[acg]

Hi Alain (and others),

I've finished my listening impressions with powering my SSD with a good quality power supply and also with an expensive 'audiophile' sata cable.  Please note that I neither run XXHighEnd nor a NOS1 (although plans are underway to change that) so of course take this with a grain of salt.

I could hear no sound quality difference from a ssd regardless of whether it was powered by a good quality linear psu or it was fed smps pc power.  There may be a difference in a more revealing system than mine, but I could hear nothing.  Likewise, when the pc was devoid of power from any linear psu i.e. was powered entirely by smps I could detect no difference between the expensive and generic sata cables.  But, when the linear psu was applied to either the PPAstudio usb card or the ssd and the expensive sata cable was in place I could hear a difference: a general crispness across the entire spectrum.  Did this sound better?  Maybe, I am undecided.  Was this difference significant?  Not in my system.  The difference was pretty faint really and considering the cost of the linear psu and the cable certainly the expense is not warranted for me.  I've heard much bigger differences tweaking the operating system or changing cables, even digital cables.

The interesting thing in all this is that the SATA sounded different when linear power was applied to the pc and it did not seem to matter if the linear power was supplied to the ssd or not.


Anyway, I'm glad I could contribute a little.

Cheers,

Anthony

[AlainGr]

[quoteA linear power supply for the PC ? I hope there will one powerful enough someday][/quote

http://www.coreaudiotechnology.com/products/music-servers/atx-linear-power-supply/

Be sure to check out the disclaimer at the bottom of the page.

Hi Brian,

Reading through the posts again, I realized I missed your post. Well a linear power supply exists... The price is steep, but expectable... I just wonder if it would be powerful enough...

There are some who suggest to put nice filtered DC to DC regulators (and filters) to reduce the frequencies effects, but I wonder if that would improve the ripple itself ?

Alain

[AlainGr]

Hi Alain (and others),

I've finished my listening impressions with powering my SSD with a good quality power supply and also with an expensive 'audiophile' sata cable.  Please note that I neither run XXHighEnd nor a NOS1 (although plans are underway to change that) so of course take this with a grain of salt.

I could hear no sound quality difference from a ssd regardless of whether it was powered by a good quality linear psu or it was fed smps pc power.  There may be a difference in a more revealing system than mine, but I could hear nothing.  Likewise, when the pc was devoid of power from any linear psu i.e. was powered entirely by smps I could detect no difference between the expensive and generic sata cables.  But, when the linear psu was applied to either the PPAstudio usb card or the ssd and the expensive sata cable was in place I could hear a difference: a general crispness across the entire spectrum.  Did this sound better?  Maybe, I am undecided.  Was this difference significant?  Not in my system.  The difference was pretty faint really and considering the cost of the linear psu and the cable certainly the expense is not warranted for me.  I've heard much bigger differences tweaking the operating system or changing cables, even digital cables.

The interesting thing in all this is that the SATA sounded different when linear power was applied to the pc and it did not seem to matter if the linear power was supplied to the ssd or not.


Anyway, I'm glad I could contribute a little.

Cheers,

Anthony

Hi Anthony,

Thanks for the output. Maybe the wall wart powering the SSD is good enough, so the linear power supply does not provide an audible improvement ? As I mentionned in my first post, the iUSB did not provide audible results ni comparison with the original wall wart... That SSD contains both the OS and XXHE. With the music drive though, the difference was "stunning", but it could be because the wall wart with that enclosure is really cheap - I don't know.

Though the "recipe" to access a silent system would depend a lot on the parts and their interactions, I suppose that the results will vary from one system to the other.

On my side, there is a frequency I can hear at times and I have not been able to get rid of it yet. I can hear it when the music finishes. I don't know where it comes from. Maybe disconnecting a few things will help to pin point this...

Alain

[PeterSt]

Get out your iPad, look for the FFT program SpectrumView from OxfordWaveResearch (free), and hold it around / in your PC;

I know of a situation that some on-board oscillator (or whatever it actually is) produces the same frequency as USB transmits, and this is 8KHz. So look for that.
The USB transmitting stops a few seconds after playback.

But of course it can be something else ...

Peter

[AlainGr]

Get out your iPad, look for the FFT program SpectrumView from OxfordWaveResearch (free), and hold it around / in your PC;

I know of a situation that some on-board oscillator (or whatever it actually is) produces the same frequency as USB transmits, and this is 8KHz. So look for that.
The USB transmitting stops a few seconds after playback.

But of course it can be something else ...

Peter

Ah !... Will try Thanks !

Alain