Does Improving PC PSU and Reducing PC EMI/RFI Improve SQ?

[earflappin]

What about a linear power supply like this one?

http://www.aplab.com/pcc/ps03-a.htm

[PeterSt]

I don't recall the numbers anymore, but IIRC a ripple of 0.04% on the current is not sufficient to let (e.g.) Firewire run.

It will look interesting in your rack though.

[AUDIODIDAKT]

3,3 vdc is for harddiscs
best
Leif

Thnx,
 
Only 5V and 12V  is needed for newer hdd's, right?
SSD only needs 5V. (maybe cutting away some acces wiring)

If it can make a difference I will think about seperate PSU's on MB.
Maybe I wait for NOS1 first, then do a litttle experimenting.
First powering soundcard and clock, then maybe try sep. psu on MB.
In this order.

[earflappin]

Here's an interesting article relevant to this thread I just came across:

http://www.anandtech.com/guides/showdoc.aspx?i=3467

Here is a link to the custom power supply referenced in this article:

http://sjostromaudio.com/joomla/index.php?option=com_content&task=view&id=57&Itemid=27

[Nick]

All,

It’s nice to get so much interest and thanks for the comments. I have tried to answer some of the questions below, its only based on my setup eg USB in to a Transit card but I hope it helps...

I will post some pics but the system is not pretty, its spread out like a bad electronics project on the bench, the problem is its never finished  . I am on holidays right now so will take the shots next week and post them.

The fans I use are
CPU fan
http://www.quietpc.com/gb-en-gbp/products/intelcooling/cnps7000c
The fan comes with a little in line voltage controller to adjust fan speed, I set it quite slow, from a 3 or 4 feet away its hard to hear. You need a bit of clearance above the CPU though as the copper fins are quite tall.

Case fan
http://www.ebuyer.com/product/97858
These Akasa have worked well.
Power Supplies

I use Audiocom linear supplies these are very high quality and designed specifically for digital and analogue audio. Place then as close to the PCI board circuits as possible. I have about 12 X Q-Powers in total (now discontinued) and 3 of the invisius supplies (these are  extreamly good but quite expensive. I looked into making my own but done have the test kit needed to ensure they can meet the standards of the Audiocom kit.

Invisius 2 regulators
http://www.audiocominternational.com/product_detail.asp?id=14
I have been doing audio power mods for a few years now on audio and these things really are more than the sum of the parts.

Lab Bench Supplies
The first one I had hanging about just a 2 amp 0-30 volt, single rail old but nice, I use this one for the M-Audio Transit Audiocom supplies.

The second is a Maplin supply, I bought this in a hurry to see what could be done powering the PC. I probably would go for the third supply below though now.
http://www.maplin.co.uk/Module.aspx?ModuleNo=5925

The third is the nicest bench supply it’s a bit big but has 2 X 0 to 30v and 1 X 5v supplies. One thing to be aware of is that it has thermal cut in cooling fans which are quite loud. They cut in from time to time. At the volumes I listen at this is not much of a problem but they are quite loud (I keep meaning to see it I can replace the internal fans with some Akasa ones) .
http://cgi.ebay.co.uk/New-Triple-Output-DC-Bench-Power-Supply-0-30V-0-3A_W0QQitemZ320370820851QQcmdZViewItemQQptZUK_BOI_Electrical_Test_Measurement_Equipment_ET?hash=item4a9796c6f3

Leifchristensen
From my experience I would not go down the mobo USB route. I have tried onboard USB on 4 laptops 3 mobos and most have not been as good as the Startach NVidia chipset USB card. On board looks hard to upgrade so for what the Startech card costs (circa £20) I would give it a go.
http://www.startech.com/item/PCI625USB2I-Value-6-Port-USB-20-PCI-Card.aspx

I have found USB cables to have quite an effect on sound quality. I tried quite a few but in the end I bought a few meters of 0.5mm pure silver wire and PTFE insulation and made one up. You only need to have the quality wire for the USB signal and the signal earth (the USB +5v from the PC is best not used down stream at all but the cable wiring can just be hook up wire). I hacked the connectors from some cheep USB cables and platted the silver wire (two cores at lease for signal +ve and earth). The cable is un-shielded but is works lots better than standard cables 

For power supply upgrades I generally work in this order;
1)   Replace the bypass capacitors on the boards with Black Gates or OsCons. Both are getting hard to get now as black gate have stopped producing. IMO they are the best you can get for Audio particularly the red / purple N and Nx types well worth the extra cost.
2)   If I can work out how to do a clock upgrade (eg apply an Audiocom Supper clock) this almost always has a good effect.
3)   For a basic upgrade I try isolate the existing supply on the card (I usually just break the relevant PCB track) and apply the smoothed supply across the bypass capacitors for the power rail. Take care this can be point of no return stuff as broken surface mount PCB tracks are hard to reconnect 
4)   For the PCI cards I have worked on it seems fine to power these separately before the PC supply is switched on. When the PC boots everything seems to sync up fine.
5)   Next a bit of research, I look out the data sheets for the USB board / Transit Card / DAC chips in my system components. It helps to get a reasonable idea of what to go for, I usually concentrate on the boards Crystal clock / PPLs (phase lock loops) / digital line drivers (eg AES outputs) where I can work out where these are. For clever proprietary DSP ICs the chances are that the data sheets are not going to be available so then your back to looking at the existing power arrangements to work out where to break in to the supplies.
6)   I have found quite a lot of PC boards and Digital Audio boards are implemented with a view to keeping cost down. Reading the data sheets can throw up some interesting simple things. For instance my DAC AD1865 really responds well to separate earths for its digital and analogue rails. This is specifically mentioned in the DAC application notes data sheet but was not well implemented in my DAC.

The PCI Bus pin out for the power pins to look at is here.
http://en.wikipedia.org/wiki/PCI_Local_Bus


With regards to mobo’s I have done the following based on part personal experiment and part reading what others have done.

I run a ASRock board. At the time the approach was to keep the system as simple as possible and to have plenty of horse power to spare for the music. In the end I went for;

1)   The simplest onboard video adaptor I could find (I read that sound cards seem to be bad news for Audio and experience has born this out to some degree).
2)   PCI bus expansion for my PCI USB card
3)   Generally a simple board because most of the extras were just going to be turned off and would only create RF and use processor and Bus time (eg minimum expansion slots etc etc)
4)   Bios with good level of control over the mobo systems as I want to turn most off them off. In particular turn off clock spreading on the CPU and this is like deliberately adding jitter to the CPU clock – doesn’t seem right for Audio .
5)   Finally I wanted a Bios that can load multiple configs as I wanted to rune dual boots one for audio with absolutely everything turned off and one for normal use.
6)   I did look at the mobo power supply (as far as possible from pics). I know that some are better than others but I already knew that I was going down the route of supply upgrades.

This is what I went for, its cheep but seems to put in a good performance.
http://www.asrock.com/mb/overview.asp?Model=G43Twins-FullHD

I have not gone as far as a separate mobo power plan (so far )but I would not be surprised to hear that it worked for sound quality. Certainly for my system turning everything off either by bios setting and or by disconnecting if it’s not used works (eg CDROMS, A Drive, Additional Hard Drives etc). Using the lab bench supplies for fans the remaining hard drive and PCI USB card is also good for sound.


Best Regards,

Nick.

[AUDIODIDAKT]

I will read all tomorrow Nick,

But again THNX for your great effort much appreciated.
 

Enjoying some Jan Akkerman - 1994 - Blues Hearts over here.

[PeterSt]

Nick,

On behalf of everyone, me not the least ... a great THANKS for your valuable efforts in the first place, and taking all this time to eleborate in the second. Really, REALLY appreciated !

Best regards,
Peter

[earflappin]

UPDATE -

After further investigation I decided to take a different tact on the topic of eliminating EMI/RFI noise and jitter induced in the AES/SPDIF ouput of computer music servers which degrades sound quality in the DAC.  Specifically, using an Antelope Isochrone DA AES/SPDIF reclocker in between the computer and the DAC.  The improvement it made in my system was immediate and very significant and I think it is a more comprehensive, simple and cost effective solution than using linear power supplies for the PC and PCI/PCIe cards.

Antelope is a leading provider of clocking solutions for the pro audio world.  Basically, the DA electrically isolates the incoming AES/SPDIF input from the computer, buffers it and reclocks the ouput using a very high quality clock.  This approach strips off incoming electrical noise and reduces jitter.  Since the Lynx AES16 card already has reportedly low jitter the greater impact may be one of just electrical noise isolation.

The sound quality improvements are truly significant.  I'd go so far to say this one component has made the biggest impact of any single component in my system except for when I changed my speakers to a high efficiency two way.  Without the DA in the system it is clear the ENTIRE sonic spectrum is being smeared or blurred.  With the DA the sound is more focused, clear, tonally rich, precise, detailed AND glare is reduced.  I would use the analogy of the difference between a blurred picture versus one in proper focus.

I suspect any good reclocker would give similar results, but I'm not going to try others (such as the Grimm Audio CC1).  The DA is not cheap at $1000, but compared to buying linear power supplies for the PC, PCI expansison chassis, not to mention the hassle, I think its a good deal.

I got mine from Sweetwater Audio which has a good return policy so it was a great risk free way to try. 

[JuanPabloCuervo]

UPDATE -

using an Antelope Isochrone DA AES/SPDIF reclocker in between the computer and the DAC.  The improvement it made in my system was immediate and very significant and I think it is a more comprehensive, simple and cost effective solution than using linear power supplies for the PC and PCI/PCIe cards.

Antelope .../... the DA electrically isolates the incoming AES/SPDIF input from the computer, buffers it and reclocks the ouput using a very high quality clock.  This approach strips off incoming electrical noise and reduces jitter.  Since the Lynx AES16 card already has reportedly low jitter the greater impact may be one of just electrical noise isolation.

The sound quality improvements are truly significant. 

I suspect any good reclocker would give similar results, but I'm not going to try others (such as the Grimm Audio CC1).  The DA is not cheap at $1000, but compared to buying linear power supplies for the PC, PCI expansison chassis, not to mention the hassle, I think its a good deal.

this remembers me this post, that says the Antelope DA does not Reclock.
http://www.computeraudiophile.com/content/Antelope-DA-Review#comment-33539
but thats only valid with the THRU AES Out, the other AES outs are reclocked, crazy post there.

anyway...
i use transformer isolation,
ETSLan.com Pa-813 vs. Canare bcj-a10tra
i like more the ETS.

becouse i have to use the s/pdif input of the converter, my converter does not have wordclock or AES/EBU input,

i like to use "no s/pdif cable", just the balun and the BNC-to-RCA-male adapter.
sound changes if adding an s/pdif cable, and all cables seem to sound a bit diferent, i was about to go crazy with s/pdif cables.
"the best cable its no cable."

from the AES/EBU out of the Lynx AES16.
"becouse AES16 does not have s/pdif out."

i also have the Drawmer M-Clock DMS-1, and it does have S.R.C. based reclock.
but i like more to send the clock to the soundcard by AES/EBU, and disable SynchoLock(TM).

usign the SRC reclock, sounds a bit strange, something changes, and that small diference can be measured with RMAA Audio Rightmark,
if doing 1:1 reclock the diference its small, but from 44.1k to 96k or from 96k to 44.1k, the sound changes too much becouse the reclocking algorithms.
http://www.gearslutz.com/board/gear-shoot-outs-sound-file-comparisons-audio-tests/348088-http-src-infinitewave-ca-src-comparisons.html

this thread, its a bit strange becouse ive never heard those EMI & RFI interferences you are talking about with the equipmen i have now, "similar to yours"

once i had a behringer ada8000 and yamaha dsp factory ds2416 with ADAT card,
and i could hear the PC Hard Drive reading & writing in the amplifier/loudspeakers like a fax modem or something.

it was an AC power issue, & bad shielded cables from DAC to amplifiers,
becouse interference cannot be transmitter by ADAT, its optically isolated
 and ADAT its the only connection possible to the Soundcard from the ADA8000, also i didnt had the WC cable becouse the Yamaha soundcard didnt had WC I/Os.
i was usign the ADAT clock, ADA8000 master, soundcard slave becouse it did sounded better.

but with Lynx AES16 ?
your problem must be in the AC power, & cables not shielded, also the DAC & amplifier sensitive Power supplys.
but any decent component to component AC power isolation & filtering should solve the problem...
equipment like: Leveler iPure, Furman P-1800 PF or AR or IT, or Monster mpp7000ss or PSAudio.com
and Monster Powerline 300 or 400 Pro AC cables or Oyaide shileded power cables ...

now i have a cooler master m700 PSU and works ok,
the MSI X58 Eclipse motherboard has a BIOS setting to reduce EMI & RFI spikes generated by the i7 920 cpu, but i have never had a problem with that feature turned off.

the only problem i have now its the Sharing IRQ with the video card and low buffer samples, i did not have that issue with older motherboard Asus P5W DH Deluxe.
now i have to use 16-Bit color to improove the soundcard at low buffer settings.
pitch starts to go crazy first, then clicks & pops "Audio Drop outs."

but tha EMI & RFI interference must be AC Power issue & bad shielded cables.

DC in the AES/EBU its rare, and sometimes its usefull, like Mutec iClock has an user selectable DC offset for the AES Black outs.
but anyway CommonMode noise can be blocked with Transformer isolation CMRR, and ETS Lan transformers sounds great to my ears, becouse it does not degrade the AES/EBU signal, & has higher bandwith.

[GerardA]

Very Interesting

but anyway CommonMode noise can be blocked with Transformer isolation CMRR, and ETS Lan transformers sounds great to my ears, becouse it does not degrade the AES/EBU signal, & has higher bandwith.

I put a Lundahl 1572 isolation transformer between PC and DAC and have very positive results.
The sound is more enjoyable, more analog like. Cristalclean highs, sweet mids and very natural bass.
So yes there is a lot of RFI-noise coming out of the PC by SPDIF.
This solution costs only 20 euro and a cap of 30 cents and a piece of wire...

And the rest will be jitter which will have to be cured by the italian reclocker talked about here before.

(Nice Christmas and happy newyear to everybody!)

[HiFiTubes]

For those non-tweakers there are store-bought solutions out here in the wilderness.

Addonics box (or similar) can be connected via eSata to the new mini-ITX motherboards, and my board runs on an 80w "laptop style" PSU (picoPSU) with a 45w AMD dual-core.

There are some nice external sound cards that can be used as transports, or you can get a more reasonable external, slap a linear supply on it, and mod if for BNC. Honestly, I don't know why many have not started with a BNC mod first (RCA digital coax bugs the heck out of me). You can even add a nice clock to this sound card. I happen to use the 1616M which is still PCI based but I have pretty low lower going on in the PC and I may get anal and go with linears all my gear (1616M, motherboard, AEA ribbon, and Black Sparrow - I'm not going to mess with batteries).

So, with the low power power mini-ITX stuff you have one SSD, off board separate power for HD but still connected with a wire (no NAS please for many reasons), and you could even use a linear supply on the  board because they are 12v at 6.5A IIRC.

I lost the site but they had linears for about $300. Given this idea that you could get a somewhat affordable linear for a mini-ITX I think you could use any PCI based-card. So, I just wanted to point out that the Pc tech. is get smaller and more efficient and allows more flexibility without having to custom design or DIY everything imo.

Happy New Year everyone.
HiFi

[Marcin_gps]

I try to isolate my sound card as much as possible from PC's noisy environment and came up with an idea to buy sth like this for my Cantatis Overture sound card:

- http://www.virtuavia.eu/shop/pci-express-to-pci-expansion-box-p29809.html

OR even better

- http://www.virtuavia.eu/shop/pcie-4-x-pci-expansion-atx-kit.html with Pico/linear PSU combo

What do you think about it? I know that Peter considered sth like that...
Greets,
Marcin

[pedal]

This is really a no-brainer. Practically all PC powersupplies are rubbish switchmode or semi-rubbish switchmode quality, both letting through and generating new distorition into the audio signal, digital and analoge.

Upgrading to external powersupply is probably one of the best upgrades you can do to a media-PC. Unfortunately there is not so many to choose from. My dream is to find (or build) an overkill linear powersupply meeting the ATX standard with the 3 voltages:
+5V     for motherboard electronics, disk drives and cards
+12V   for disk drives and some cards
+3.3V  for the majority of modern logic electronics in motherboard
-12V   for some accessory cards

(Heat/silent cooling is also an issue. May it should feature big passive cooling wings?)


If anybody can find such a thing, please inform me!


EDIT: Here is a link to DIY Audio about the same thing: http://www.diyaudio.com/forums/power-supplies/100095-linear-pc-power-supply.html

[PeterSt]

I know of a company who just put into production a linear PSU at the size of a matchbox, especially made for PCs (ATX connections). No fan in that matchbox as well, hahaha.

I am not sure it is too early to tell about though, and I don't think they have a sales channel for it yet. But since I am a customer there already ... who knows. The price is (don't laugh) around a 100 euro.
The "inventor" of it is an audio freak himself ...

I don't know how good it really is, as I didn't have it in my hands myself. IIRC 5Amps can be drawn from it.

[pedal]

This is very interesting. If they do it "right" I think they can sell hundreds, as PC-audio is catching on.

Mass-production, universal technology and the "China-effect" has brought down the price and lifted the performance on all kinds of stereo equipment. That's a fact, and that's very fortunate for all of us. Today you can purchase a "highend" system at unbelivable low price. But, there are still some factors which cannot be bought cheap. One of them is oversized clean power supplies. Here, I belive there are big improvements to be made.

A couple of years ago, Stereophile published jitter measurements from a Mac laptop running on its battery vs. the standard external switchmode powersupply. The jitter increased 10-fold with the switchmode in use...