I am interested in other users experiences. I have always understood that a computer is very bad thing to have on the same power supply as the hifi system. All that high frequency hash!!!.
Hi PC,
I got the PM from Peter on your question and thought I might be able to share you some of my 2 cents experience. First let's try to understand the problem so corrective action can be derived.
Why most people think that PC is so polluted?1. Moving part especially from all sort of fans eg. CPU fan, PSU fan, GPU fan, case fans, HDD motors, optical drive motors, etc. Moving parts can generate a fair amount of EMI pollution in PC case. There are some folks in Overclock.net who experimented EMI effect on HDD latency. They measured HDD latency when it was installed inside and outside the case by routing SATA cable around the back of the mobo tray to shield it against EMI in the case. The result was interesting. Outside was 15.4 ms and inside was 22-28 ms. Higher latency = slower access time.
2. Switching power supply : it is a basic knowlegde to all audiophiles that standard switching power supply generates large amounts of switching frequency based pollution - RFI and EMI. They have been used in certain audio power amplifiers (namely pro audio and autos), but were not taken seriously for high quality home users. They were also more expensive than passive transformer based (linear power supply) products. However hi-end reputable name like Mark Levinson has launched digital power amp using switching power supply. Check this link
http://www.marklevinson.com/ProductDetails.aspx?prdid=1 I doubt if interleaved switching power supply based amp can gain trust from fellow audiophiles.
Solution :1. You may find thread discussions on XXHE about fanless PC to eliminate both noise (audible one) and EMI/RFI noise. I use water cooling - not easy to work with especially when you want to exchange and play around with CPU or GPU. You have to be careful with the water leakage and tubing maintenance. But the beauty is that it is completely quite and with less pollution. Mine is Zalman Reserator 1 with large cooling tower. Don't buy the one that has extenal fan attached to the cooling tank (Reserator XT :
http://www.zalman.co.kr/eng/product/Product_Read.asp?idx=185) If you decide to go for water route, you have to be prepared to void your GPU warranty since you have to remove the stock heatsink and replace it with GPU block. But the effort is very rewarding.
2. Fanless can go further into PSU. Some folks in XXHE circle use fanless PSU. Some removes PSU from the case and place it outside. I know that Suteetat is hiring an audio geek to build a linear PSU for his music server- IMHO a project too ambitious to be true. Mine is a fan one -SeaSonic 850W- but will kick in only when the PC pulls more than 20% of the rated load. It uses Sanyo double ball bearing variable speed fan which is very quite too.
3. Mobo selection can be helpful. Make sure that your mobo has large heatsink on the northbridge and preferably southbridge as well since you may choose to power off all case fans. I don't think you can find aftermarket heatsink for northbridge. But you can get water block for this from Zalman. My G1 Sniper has a massive machine gun look heatsink.
4. Application of EMI/RFI shielding materials : you can build your own metal box to form a Faraday cage to your internal sound card (a means to block out external static electric fields which is in existance since 1836). I use Stillpoints ERS paper to shield my Lynx AES16 card (before I bought NOS1). Please see photo how I shield the Lynx card. ERS can be purchased online at
http://www.tweekgeek.com/_e/Stillpoints_ERS_More/product/ERS/Stillpoints_ERS_RFI_Killer.htmIf you open NOS1 case, you will find 3 compartments each separated by steel wall. These are Faraday cages. DAC compartment is in the middle of the H shape (under your initial !) and is the most important part to be shielded against noise pollution. Peter moves Juli@ card outside of the PC case just to feed it with linear power supply and to keep it away from noisy environment.
5. SSD to eliminate moving part. But we know that spinning disk will give a better SQ for XX.
Is it a good idea to run PC and NOS1 in a separate circuit than your dedicated audio power supply circuit?I don't know. I haven't test it with a critical listening materials. But I will and report back later. But theoretically speaking, you wouldn't want to run your PC and especially NOS1 in a typical home circuit which hooked up to refrigerators, washing machines or any home appliances with motors. The pollution can find their ways to "sneak into" your high-end dedicated audio circuit. And *that* will have a detrimental impact on SQ. The noise generated from a well configured music server PC is much lower than those from washing machines.
I am still running my NOS1 in a breaking in mode ie 24/7 basis. I am already half way through a month of burning in. Both of my PC and NOS1 are connected to true online UPS (placed outside my listening room) to protect against system failure and potential damage to Juli@ card inside NOS1. Please read this
http://www.phasure.com/index.php?topic=1445.msg16633;topicseen#msg16633Hope this will help.
BTW, what is your new desktop PC configuration?
cheers!
Praphan