Crazy EMI/RFI with low power PC

jrebman · « **Reply #40 on:** 25 Mar 2010, 03:52 pm »

Are you using the latest drivers? Or, have you tried going back to an earlier driver? May not do much, if anything, but it may be worth a try. I'm guessing it's just a design issue with that particular board, but that too is just a guess.

Sorry you're having to deal with all this.

-- Jim

doctorcilantro · « **Reply #41 on:** 25 Mar 2010, 04:20 pm »

Yep, forgot to mention that. I rolled back to last (3) ATI drivers and used the stock Windows 7 VGA driver too.

Thanks Jim!
J

doctorcilantro · « **Reply #42 on:** 25 Mar 2010, 06:20 pm »

Forgot to mention, the reason I called the Cardas cable "magic" is that it filtered this noise out when connecting tuner or Oppo to the Nova.

Finally, the question of the week:

Why is the Matrix Mini-I Dac headphone output filtering out this noise to my JVC DX1000 headphones? (the same DAC which pushes the noise to my power amp)

take care all and thanks for the moral support & tech advice!

DC

Telstar · « **Reply #43 on:** 25 Mar 2010, 07:14 pm »

DC, don't waste any more time and change the mainboard (with a different one).

doctorcilantro · « **Reply #44 on:** 25 Mar 2010, 07:30 pm »

YES~!! Stay on target, thanks!

doctorcilantro · « **Reply #45 on:** 25 Mar 2010, 08:28 pm »

I'd like to try the Winmate with my new board. Where did you get the AC adapter for it? Or did you buy it as a package?

thanks!
DC

Quote from: Telstar on 23 Mar 2010, 09:01 pm

It looks like psu or motherboard related.

I have a Winmate dc-dc psu which is similar to the pico but much better quality. Before i had a normal psu (with fan).
Replacing the psu with one proved to work is a good idea. The pico is not well filtered and may be the cause. Also it could be just the wall wart that you use with it.

If it doesn't work, go for the mainboard.

Telstar · « **Reply #46 on:** 25 Mar 2010, 08:38 pm »

Quote from: doctorcilantro on 25 Mar 2010, 08:28 pm

I'd like to try the Winmate with my new board. Where did you get the AC adapter for it? Or did you buy it as a package?

thanks!
DC

Package.
The guy selected a few wall warts. I have the 130W gateway one. Not cheap (esp. shipping) but worth it imo.

doctorcilantro · « **Reply #47 on:** 25 Mar 2010, 08:39 pm »

Interesting thread on Pico vs. Winmate.

Dc

Telstar · « **Reply #48 on:** 25 Mar 2010, 08:47 pm »

Quote from: doctorcilantro on 25 Mar 2010, 08:39 pm

Interesting thread on Pico vs. Winmate.

Dc

I have the OrigenAE H5 case, with the onboard mATX psu (so no big psu for me), and needed a totally fanless system (which is NOT iATX, but a rather powerful intel dual core).

ATM I have an internal soundcard, and the Winmate with the Gateway AC adapter sounded better than the OrigenAE PSU. For me the internal card is a temporary solution, so my goal was fanless and cool. Fanless traditional PSUs would have put too much heat inside my case.

doctorcilantro · « **Reply #49 on:** 25 Mar 2010, 08:53 pm »

I used to have an X11; nice cases.

I have fans in my cabient, as shown, and the PC is naked.

I'm curious to hear more about what people are doing for power as I'm trying to figure out if I will stick with the Pico.

My EE DAC doesn't hold sync and I think it's due to my power issue as I'm on the 3rd one.

Quote from: Telstar on 25 Mar 2010, 08:47 pm

I have the OrigenAE H5 case, with the onboard mATX psu (so no big psu for me), and needed a totally fanless system (which is NOT iATX, but a rather powerful intel dual core).

ATM I have an internal soundcard, and the Winmate with the Gateway AC adapter sounded better than the OrigenAE PSU. For me the internal card is a temporary solution, so my goal was fanless and cool. Fanless traditional PSUs would have put too much heat inside my case.

doctorcilantro · « **Reply #50 on:** 26 Mar 2010, 05:59 pm »

Long story, but I can get a replacement board from Jetway for free and there are some features I really need like dual e-Sata and port multiplier support (and PCI slot) which are literally not found, together, on any other mini-ITX boards.

So we'll see. Maybe it was a heat issue in my cabinet; I think I added more fans when one of my drives failed (but it was a WD Green drive that had a bad batch IIRC).

If this doesn't work, I will move to a Minix 785G board with PCI-E (or the next Jetway up the line which still has PCI), but that means I need to sell my Lynx AES16 PCI of course.

Honestly, I'm really impressed with Jetway CS. http://www.jetwaycomputer.com/Contact.html

Never noticed their USA contact point, called and got a very friendly casual, "hey how can we help you" after 1 ring. NOT what I expected from a motherboard maker. 2 year warranty which is nice.

DC

doctorcilantro · « **Reply #51 on:** 26 Mar 2010, 08:42 pm »

I was thinking about trying a cheater plug in the meantime. The AC adapter that came with the PicoPSU changes the sound when I move it in my hand. AND, If I push the AC plug to one side on the brick, the noise changes and lessens dramatically.

So let's say there is a grounding issue somewhere and the noise should be dumped to ground but is not; it is still amazing how much there is and that the connection on the AC adapter makes such a difference.

I need a simple and elegant power solution.

There seems to be some disagreement over whether or not the Pico PSU has a benefit or not, in that it passes the 12V unregulated and direct for the AC adapter. The Winmate is supposed ot have more filtering. The PicoPSU has solid caps but some say too small; the Winmate does not use solid caps.

I'm not an expert so I don't know what matters. I may want to try a linear powering either 3.3., 5. or 12v on the PC though.

doctorcilantro · « **Reply #52 on:** 3 May 2010, 03:34 pm »

Quick update.

Got the board back and the problem remains. It seemed like a new board and the onvoice seemed to note that.

I was able to reproduce the intial EMI issue:

With the PC disconnected from the amp, the EMI gets into the system.

My new theory is that the giant heatsink I use is acting like a powerful antenna.

Now I have to decide if I am going to stay with a small system or just build more of an HTPC. I'm tired of spending money and less interested persuing linear power supplies and alternatives to the PicoPsu so I may just start with this Antec case and psu.

Anything will be better than this horrible EMI.

DC

Quote from: doctorcilantro on 26 Mar 2010, 08:42 pm

I was thinking about trying a cheater plug in the meantime. The AC adapter that came with the PicoPSU changes the sound when I move it in my hand. AND, If I push the AC plug to one side on the brick, the noise changes and lessens dramatically.

So let's say there is a grounding issue somewhere and the noise should be dumped to ground but is not; it is still amazing how much there is and that the connection on the AC adapter makes such a difference.

I need a simple and elegant power solution.

There seems to be some disagreement over whether or not the Pico PSU has a benefit or not, in that it passes the 12V unregulated and direct for the AC adapter. The Winmate is supposed ot have more filtering. The PicoPSU has solid caps but some say too small; the Winmate does not use solid caps.

I'm not an expert so I don't know what matters. I may want to try a linear powering either 3.3., 5. or 12v on the PC though.

doctorcilantro · « **Reply #53 on:** 18 May 2010, 12:59 pm »

Pinging Davidr...HELP!

I have the new system in place, and with my MAC Reference cables these noise is there on the new system; if I use my buddies homemade cables the noise is about 5db quieter (cheap iPhone DB meter) at the same gain.

I'm turning up the gain on the mini-Torii, w/ volume bypassed on the DAC, to a level that is not super loud but a nice big lisenting level, about 12 on the volume controls, maybe 1-2 I can hear the noise, but with the MAC cables it is rather loud.

I now have a completely new system:

WinMate PSU with Lite-On AC brick rec. by Electrodacus as the best psu of this formfactor
Aluminum M10 case from OrigenAE (has a ground wire running off it's black power socket lead to chassis)
Lynx AES16 PCI-E
Zotac ION LE motherboard and ATOM 330 cpu

These are ALL NEW components and I HAVE MOVED 30 miles away and I have the same type of noise, and can hear the mouse when moved.

Granted this is at a high gain level but I'd be in the same position if I had the 1st amp which had fixed output.

This amp is max 6 watts too where my last was 10 watts!

I woke up today with a headache.

All I can think of right now, is how I borrowed my neighbors PC (way upthread) , and had no isse with noise.

I have tried (3) mini psu's at this point: The OrigenAE M10, PicoPSU, and the supposdely best WInMate in a completely new system with new amp.

Bout to give up. Am I just being anal? I fixed a ground loop by pulling the coax out of my cable box (HDMI connection from this PC to TV was linking it) and this static is louder than that hum/buzz...so I don't think I'm asking too much.....

doctorcilantro · « **Reply #54 on:** 19 May 2010, 01:26 pm »

So far I gave tried a PicoPSU, WinMate, and Origenae M10 stock dc-dc psu....all 3 cause EMI to ride my AES cable to external DAC....UNLESS I float the ground on the PC.

Go figure.

davidR · « **Reply #55 on:** 19 May 2010, 03:25 pm »

Jon, so all is well? Grounds shmounds what a hassle.. I have an extra full sized ATX supply I could've sent you. Do you still have any noise at all? I'm glad you found something that worked! I don't think you are being anal at all; you shouldn't have to live with noise.

doctorcilantro · « **Reply #56 on:** 19 May 2010, 03:28 pm »

Thanks David!

I floated the ground on the PC, something I should have done months ago (I thought I tried this), and it's a temporary solution.

The noise is gone, but I am going to float the ground on my AES cable by pulling pin-1. The Lynx is transformer isolated and I have read that any device using an AC power adapter is not tied to AC ground, thus the chassis is not directly tied to ground.

I had tried ground my case to Earth ground before though. Anyway, I'll start with the AES cable I think.

davidR · « **Reply #57 on:** 19 May 2010, 04:35 pm »

Jon, do you run wireless internet? Any routers near your listening space?

doctorcilantro · « **Reply #58 on:** 19 May 2010, 04:49 pm »

Quote from: davidR on 19 May 2010, 04:35 pm

Jon, do you run wireless internet? Any routers near your listening space?

I had the noise with and without router in the listening room. Now it is currently in another room, but I had every breaker off in the house and just essentials powered up. I tured off cells, fridge, etc.

The sound is direct psu noise from the PC (2 different ones); I think when using dc-dc converters like PicoPsu in certain setups.

Upthread you can read about how the noise would react to loading the cpu down or changing gpu clock speeds. I tweaked many BIOS options too but it just seems like overall bad grounding. Now that I am running "bad" grounding, against NEC code, it sounds great.

I reverted to a grounded PC and plugged in the 3 involved components power isolation transformer (Panamax 5510) and still had the noise. Something is coupled direct to that pin1 on the AES at the PC end and getting in.

davidR · « **Reply #59 on:** 19 May 2010, 09:32 pm »

Interesting. I'm assuming your neighbor's PC used a full sized ATX supply? It seems like something is up with the Pico. Is the Lite-On a 3 prong adapter? This might be an alternative for the ground problem. http://www.bhphotovideo.com/c/product/365781-REG/Ebtech_HUM_X_Hum_X_Ground_Loop.html I've spoken with other listeners and they recommend this gadget. Doesn't funk with the sound / dynamics etc..