I replaced a wall wart with a linear power supply

[AlainGr]

I have had the NOS1 since January 2013 and have been very happy with the SQ that was added to my audio chain. It replaced a Bryston BDA-1 dac that I enjoyed very much before.

While I was using this previous dac, I tried a few power supplies for the Audiophilleo 2 USB to SPDIF converter, that was directly plugged at the dac input. This converter is normally powered by the USB 5 volts that comes from the PC. To improve the SQ, I got  an Aqvox USB power supply, that replaced the "noisy" power with a clean 1mv ripple power.

Then I heard about the iFi iUSB power supply, with its 0.1uV ripple - better than the Aqvox. Bought it.

I "thought" that each change was doing something good. I am using  "thought" in quotes because there were slight changes, but I could not really turn them into images. Anyway, if I did not try, I would never have known...

When I removed the AP2 + Bryston in favour of the NOS1, I had concerns about putting anything in between the pc and the dac. It seemed that Peter had thoroughly thought about every aspect between pc and dac. XXHighEnd is so musical and adjustable that putting anything else would have been "heretic".

The Aqvox was not needed anymore, so was the iUSB.

And for the first time, I could use the Sotm PCIe USB card that had been idling in my PC, because there were latency and/or buffer problems (Blue Screens) with the Audiophilleo before.

With the Sotm, I can cut the power off (5V) (there is a switch right beside the USB connection on the Sotm) after XXHE has established a connection with the NOS1.

But after a while I decided to put the iUSB "back to work". I removed the SSD that was in my music pc and put it in an external enclosure, like the music hdd (2TB, 7200rpm). The two of them are connected to the pc through Esata. The SSD holds W8/64 pro and XXHE. So now the iUSB powers the SSD.

Did I hear an improvement ? Not really.

5 days ago, I received another linear power supply, this time for my music hdd. While the price of that linear power supply is twice the value of the drive + the enclosure, I again took a chance.

Let me put it this way: I am not very sensitive to slight variations in SQ, way less than many of the posters in this forum. I tried very few USB cables, had paid quite an amount of money for interconnects and AC cables... But NO, I did not really feel that there was an improvement in SQ. I can't specify if a USB port is better than another, not even if I compare them with the Sotm USB card... I apply recommended tweaks, try a few others, appreciate what I can learn from fellow posters. As for my hearing abilities, well all I can say is that I am happy to still be able to hear something, as I have abused my ears many eons ago. 

With this in mind, I was not expecting to hear a damn difference.
I have read a lot of descriptions about one's perceptions but to image what I perceive now is hard for me. The nearest approximation that I can give would be something like "Tthere is AIR between the notes"... It may not be it, but it is surprisingly good. The LF are tight, the notes are clearer... It is as if a "sizzling" was removed.

In each step of my journey, I have heard some improvement through time, but at a certain point all has been subtle and my expectation bias is not high. Most of the time, I would say that except for XXHE and the NOS1, many expenses were done for not much.

If you have the chance to find a linear power supply that will fit with your budget, try it. The power supply I bought is a TeddyPardo brand, model "Teddy12/4"). There is also the "Teddy12/2" power supply. I chose the 4 amps version because it could accommodate more powerful devices (48 watts max), but the 2 amps (24 watts) will certainly fit perfectly for a hard drive. As long as the DC voltage output is the same as the wall wart  it replaces, and the amperage is equal or higher, the power supply should be perfect for the job.

There are other brands and I am quite sure that they would achieve what I am perceiving now.

This TeddyPardo power supply is expensive if you compare its price vs the price of a hard drive + its enclosure. But if I can hear what I hear now, you will most likely hear something too.

I don't like to write superlatives, because I don't feel it is necessary. I can only try to contribute with fellow audiophiles what I am perceiving now.

A linear power supply for the PC ? I hope there will one powerful enough someday

Alain

[juanpmar]

Great post Alain, and thanks so much for sharing your findings, I´m sure you can hear more of you say and you say many useful things. Reading your post I remembered that I had in some place the Aqvox that I used some time ago, I´ll look for it to see if I can use it again. About Teddy Pardo I took a look to his power supplies and they look very interesting. Please let us know your experience with the Teddy Pardo when you have some more time with it.

Kind regards,
Juan

[AlainGr]

Thanks Juan for the kind words

The power supply is still making its magic on the rendering. Now I know that what has changed is the level in noise. It is a lot "blacker" than before and because of this, I can "feel the matter" much more.

Regards,

Alain

[boleary]

[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.

[PeterSt]

... and the extra box. And the 50LBS.

Wow ...

[boleary]

Do you think the 200 watt "S1" is enough power if fan-less and one HD?

[PeterSt]

Yes. But it sure is in the danger field. So, I was thinking about the XXHigHEnd PC. Here the processor consumes 130W max. Video card a bit, a disk a bit, Mobo, things you don't think about and ... close to it.
So with this 130W processor I would not do it. Then rather 500 buks extra. Nothing tells about 50LBS extra, so ...



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.

Peter

[boleary]

I thought the extra 500 would yield an extra 10-15 lbs.  Did you see they build a music server for $65,000?

[acg]

Hi guys,

First post here.  Downloaded XXHighEnd a couple of days ago, thought I might also try to contribute.

Linear supplies...I'm playing around with one at the moment that feeds the usb output from the PC.  Now my PC is a quite a bit different to the ones recommended for the Phasure PC...passively cooled i7-3770T, 8GB ram, ssd for os, pico psu et cetera.  My dac is also a lot different to the NOS1.  

Two things that have improved my setup are: a customised PCIe - USB card (similar to the SOtM card that AlainGr has installed, but it has been modified with better TCXO, a little silver output transformer and some other goodies and must be fed its own power source); and the EA Shortblock Common-Mode filter.

On trial at the moment I have the Adnaco S3B with a high quality linear psu to head-to-head against the modded USB card mentioned previously.  I can tell you that the linear psu makes a significant difference to the Adnaco, but I am not yet sure if the Adnaco is for me.  I will power the modded USB card with the same linear psu to compare results.

Another project that I have on the go is to try to build an atx linear psu for the pc, but that is not going to happen overnight.  One thing that I have gleaned from others that have gone the linear psu to the pc route is that the quality of regulator module and components is paramount:  not only low ripple but ultra-fast response also.
I will do some more digging on this site and try to figure out the recommended PC build for XXHighEnd and the NOS1.  Maybe then I can help some more with the linear psu and other recommendations.

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)

Cheers,

Anthony

[acg]

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. 

[AlainGr]

Hi Anthony,

I am very interested in the conclusions you will pull from your comparison between the Adnaco S3B and your modded PCIe USB card.

You should see in one of the thread that it was tested about a year ago... The results were mixed at the time, more on the negative side... My attempts with it were not successful then (had problems with the Audiophilleo and BSODs)...

I did not like the sound then when I could play it for a few songs...

http://www.phasure.com/index.php?topic=2089.0

Alain

[acg]

Hi Alain,

I have done my critical listening today comparing the Adnaco S3B and the PPAstudio USB card both fed with a high quality linear psu of similar quality to the Pardo unit you have Alain.

I have had the Adnaco + linear psu in my system for three days now (on loan from a friend) and I must say that in general I thought that it was a step up from the PPAstudio card when fed by the internal PC smps power.  I have previously tested the SOtM card against the PPAstudio card and for me the SOtm was easily bested.

One thing that I can say about the Adnaco while it was in my system was that for all the improvements in clarity and cleanliness it brought it also had some unwanted baggage.  The upper mids and treble were 'steely' and 'thin' to me, and not as accurate as I thought they could be.  I never tested it with the standard wall-wart, but the owner of the unit said that the linear psu brought a very significant step-up in sound quality.

This morning I made up a cable to extend the linear psu feed to the PPAstudio card so that it received exactly the same feed as the Adnaco.  There is not much to say other than for me the PPAstudio card fed linear power was significantly better than the Adnaco.  The entire sound signature was fuller and more refined and the 'steeliness' had disappeared.  My brain is better able to read the spatial cues and when playing rock like The Drones, Daft Punk or The National the drums seem more solidly placed within the soundstage and just a little further behind the guitars than with the Adnaco, more 3d if you like.  I like it, I like it a lot.

I hope this information is useful Alain.  I will now do a search and see what the Adnaco thread has to say here.  I may even agree with someone!!

Cheers,

Anthony

EDIT:  Have read the Adnaco thread...I am in general agreement with the main protagonists there...phew.

[AlainGr]

Hi Anthony,

Thanks for the information - really appreciated Noise is hard to conjure, but it was about the first time I discovered its merits when I added the linear power supply to power my music hdd. It really has been a revelation. It seems I am more sensitive to certain aspects of audio, while for other things I can't appreciate a difference...

There is something I am not sure. I think that Peter mentionned it more than one time, but can't locate it. It is about elimination of the noise right from the start.

Does the noise that would have made its way through the signal prior to the Adnaco still remains even if the data is converted into light, then back as an electrical signal... This I wonder...

Would jitter explain the SQ you experienced with the Adnaco, as it is often described because of the conversion at the start and end ?

Do you have a link where I could get more information about the USB card you mention ?

By the way, welcome among us

Regards,

Alain

[AlainGr]

Anthony,

Would it be the Paul Pang USB card ? I read some info about it some time ago...

I wonder if he also makes Esata cables...

Alain

[acg]

Yes Alain, it is the Paul Pang card.  Have a look near the bottom of this page.

He makes quite a few things including sata, lan and usb cables.  I have one of his sata and usb cables on loan here at the moment and am going through the process of getting my head around them.  I can't think of a single good reason why a sata cable would improve sound.  The only thing that I can come up with is perhaps if it acts as an antenna for emi/rfi but that may be tenuous as best

Tomorrow I will make up a power cord to run my os ssd from the linear psu.  Then I will try it on the music ssd (which strictly speaking does not exist because I network the music files in from a NAS at present) but I will pull one out of another computer and plonk some music files on it to do some listening.

You are not the first to report that powering the ssd or hdd has an impact on sound so I will be very interested to do these little experiments.

I can tell you that on two occasions where there was no linear power to the pc that I could not pick a difference with the expensive sata cable that I have here.  However, tonight, with the linear psu feeding the usb card I could pick an extra 'crispness' and 'clarity' to the sound I was hearing.  It is important to note that I am not convinced of the change as yet and need to do some more listening over the next day or two to confirm it.  It could simply be placebo or psychoacoustic.

I don't know the technical aspect of why the Adnaco did not work for myself and others.  Maybe it is jitter: I understand that the conversion can induce jitter.  But the 'steeliness' I heard did not sound like jitter I think I have identified before.  Like many I am but an armchair expert!

I will let you know how I go with my ssd experiments tomorrow.

Cheers,

Anthony