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Posted this on the sweetwater forums, but haven't received any responses yet. Really looking to take care of the problem sooner than later..so I'll post it here too... Anyway, this is the story:

Am I the only one that gas the sliders on my board (Mackie 24x8), then hear little pops from my keyboard typing away in my headphones? If I move the mouse, I hear a buzz. If the hard drive does it's thing, it's another kind of chunkier buzz. I can also watch the -40db lights on the board blink with every key I hit on my keyboard. And no, I don't think I've got my input gains way too high...in fact, they're turned all the way down.

I'm wondering if it's got something to do with having to adapt from 1/8" mini stereo out up to 1/4" unbalanced ins on the channel strip due to my current soundcard? Ground loop maybe? Would a soundcard (been thinkin about an mBox anyway) with a pair of balanced 1/4" ins & outs be a ton quieter?

It never bothered me until I did some testing with my Mackie MDR. Played a CD on the PC, recorded it with the MDR & then dropped the Mackie's removable drive into the PC & played it back again. The audio level is down just a touch from just listening to the CD, but the noise is awful & definitely apparent.

Help?
Todd

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MisterBlue Fri, 10/31/2003 - 20:23

I had a similar problem in the past and thought that I was losing it - there couldn't possibly be noise in the audio output when I moved my mouse ... ! Even when no audio was playing.

Here is the good news: It's gone.
Here is the bad news: I don't know why.

Did you play around with the wiring around your computer ? This is a common way of getting noise into the audio path. Keep power and signals separated as much as possible.

Could your audio card be catching the noise (because it is not well designed or shielded)? Did you try and move the audio card to another PCI slot ?

Sorry, probably not a lot of help but give it a try.

MisterBlue.

anonymous Fri, 10/31/2003 - 22:49

Well, as far as the 'audio card' it's the CMI8738 onboard chip in a Soyo Dragon Plus mobo. I bought the dragon mainly because of the optical ins (I figgered I might need them sometime, I've changed my mind) and the onboard lan. Otherwise it would have been an asus..

I have noticed a couple of things that could 'possibly' be the trouble, but nothing I'd go spend money on to replace. Some people have said 'ATI vid cards suck on a DAW'...and that's precisely the brand of card I have. Another site had a little blurb about PCI bus noise..and I just dropped a cheap firewire card in an open PCI slot just before I noticed this phenomenon. Of course..I've never just cranked up the channel to listen to it before either, so who knows if that's the trouble..

I honestly don't think it's actually being caused by the onboard audio chip or anything related to it. With the onboard audio chip disabled through bios, the lights are still blinkin away on my mackie as I type this. It's gettin irritating..

Todd

MisterBlue Sat, 11/01/2003 - 19:52

Well, the signals have to get to the output somehow. If the chip is disabled and there is still noise on the output line it only hardens the suspicion that the problem has to do with the layout of audio signals inside the computer (in other words : on the motherboard). It's VERY tough to get that right and in reality basically nobody does.

The solution is to bypass the whole thing altogether by getting a decent PCI sound card. Frankly, using the onboard audio chip translates into the equivalent of a $5.00 sound card. How much would you trust such a piece of hardware?

MisterBlue.

anonymous Sun, 11/02/2003 - 09:41

Yeah yeah yeah...I know. When I built this machine, There was a wasn't much of a chance it would be used as a DAW, so I didn't pay as good of attention to the audio side of it as I should have. I am planning on doing a 24/96 2rec/2play PCI card, or an mBox, but would really like to be sure this noise is gone before I dump the $$$ out.

Anyway...pulled the cover off the case, yanked the firewire card, disconnected all the cables I could off the back of the machine & moved all the cables inside it as far away from each other and the motherboard as possible. Changed the ATI vid card with an nVidia card, connected a ground strap from the computer's power supply case to the shield side of a TRS plug & plugged it into the 24x8, and disconnected the MDR, preamps & processors from the 24*8 completely so the only thing connected is the computer. Disconnected the USB keyboard and mouse, and the $**&^% noise is still there!!

I've ran out of ideas other than trying a different power supply and/or changing the motherboard.

Anyone else have any ideas? I really appreciate the input this far.

Todd

anonymous Sun, 11/02/2003 - 12:04

I will seriously recommend, to re-check not only the cables but the grounds on your mains check verything is on phase and make sure that all cables are truely grounding equipment. On the other hand try using a PCI card instead of any USB I have had so much trouble with USB devices even the mbox I would rather go with a PCI or a FW.

SAK =)(=
---

MisterBlue Sun, 11/02/2003 - 13:50

Originally posted by Omega21:
Anyway...pulled the cover off the case, yanked the firewire card, disconnected all the cables I could off the back of the machine & moved all the cables inside it as far away from each other and the motherboard as possible. Changed the ATI vid card with an nVidia card, connected a ground strap from the computer's power supply case to the shield side of a TRS plug & plugged it into the 24x8, and disconnected the MDR, preamps & processors from the 24*8 completely so the only thing connected is the computer. Disconnected the USB keyboard and mouse, and the $**&^% noise is still there!!

I've ran out of ideas other than trying a different power supply and/or changing the motherboard.

Todd

Todd,

forgive me for saying it, but you have tried about everything EXCEPT for what is most likely the real problem (namely the soundchip and the layout of wires around it on the MoBo).

Now stop pulling your hair out, get yourself a half-way decent PCI sound card and move on with your life. If you have a Guitar Center or similar around you can easily take the card back if it doesn't work. Or mail-order the card and tell them that you will send it back if your noise problem isn't solved.

MisterBlue.

anonymous Sun, 11/02/2003 - 17:39

forgive me for saying it, but you have tried about everything EXCEPT for what is most likely the real problem (namely the soundchip and the layout of wires around it on the MoBo).

You're forgiven and I honestly think you're 100% right. I just wanted to elminate every other possibility beforehand is all. I just didn't want to get the card in there to find out it's something else and I have to keep screwing with it.

Thanks again
Todd

anonymous Sun, 11/02/2003 - 19:31

Omega - do heed the posts regarding your soundcard - a better one will give you better sound. HOWEVER - there are some cases that I've seen first hand where driver conflicts and PCI slot order do tend to screw up the audio, especially on lesser PCs. I had an Emagic Audiowerk 8 as my first card - the thing was, first of all, noisy because the AD was done on the card. Aside from that, the card would never get grounded properly into the PCI slot (and it never fit quite right) - I ended up having to wedge a paperclip between the rail of the card and the metal chasis of the computer case to get it to gound. That took card of some problems, then of course, I had to rearrange my audio card so that the video card wouldn't screw with it, reinstall like 10 different drivers, and pull my video hardware accel. down to level 2, instead of the windows default level 4. Pain in the ass - so I sold the card. Got a nice Yamaha DSP factory (now coupled with Pro Tools LE Digirack 002) which has been working flawlessly for about 4 years. The difference was about $100 for what I considered a high level card when I bought the yamaha - and it came with tons of onboard DSP (kind of important before we all had the faster computers of the last 2 years).

Spend some bucks on a decent card - but if you get some noise, maybe my trials will give you some ideas - but don't try the paperclip thing.

Steve

anonymous Sat, 11/08/2003 - 23:43

Alright. It's got a Terratec 24/96 mastering card in it now, and the on board audio disabled. I've unplugged the CD rom's analog cables & disabled digital playback for both of them in XP. As far as playing audio, it sounds awesome & it's a night and day difference.

The problem is that the new card has made the noise much more refined & dynamic!!

Any ideas??
Todd

anonymous Sun, 11/09/2003 - 10:09

Unfortunately, it's not only the mouse & keys that keep making noise in the audio. With the new card I can hear the HD's power up & be accessed, the mobo fans take off, and every inch of processing happen. The new card has actually made the noise worse. I even went as far as to swap power filters from one brand to the next to see if it would go away & it doesn't. I moved the card accross all pci slots & no difference.

So...unless someone pipes up with some brilliant idea nobody's thought of, I guess the next move is to swap power supplies out with my wife's computer? At least if that changed the noise, it would give an indication of where the problem lies.

Todd

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