Annoying analogue noise in my desktop rig

[selkin]

Quote:

Originally Posted by obobskivich /img/forum/go_quote.gif I love how nobody has actually read his system specs, and sees that he's using an external USB device already

Thanks for pointing this out. didn't know it's just me who's missing something as I know nearly nothing about coaxial solutions.

However I do have an s/pdif output on my motherboard's backpanel. No, I even have coaxial out too.
Wonder how could I take use of them.
check backpanel connectors

As for trying to leave out the mixer: I did that, and I just got the noise "cleaner"

The mixer is just kinda filtering it out, along with other sounds that shouldn't be filtered/muted at all

I plan to change it to a mackie 802 later anyway.

So RFI goes trough USB: yes the noise is there, definitely. But the signal through a coaxial out could leave behind the noise, as it's just light, couldn't it?

about my case, fallen angel: it's a Lancool k10, made of aluminium and steel. don't know how does this affect RFI leaking in, but that's what it made of. I bought it a couple of weeks ago as a "good quality case", so I can eliminate an other possible cause of the noise.


obobskivich: what is considered as top quality psu ? Do you know any brands ?

 

[selkin]

found some posts in an other similar thread, it has some useful info in it (to me)
I just copy it into here so it's in one place:
Quote:

Originally Posted by infinitesymphony /img/forum/go_quote.gif It sounds like internal computer noise bleeding through to the audio. Perhaps the wire that's connected to your front panel is picking up interference from the other components. Most sound cards have front panel output, so you could see if that makes a difference, versus connecting directly to the motherboard's front panel output.

Quote:

Originally Posted by KarateKid /img/forum/go_quote.gif Is there any easy way to eliminate computer noise? Like a quick mod or something? Does interference ever bleed through the PC to an external DAC when one uses a decent coaxial cable (say a bluejean)? Or is that unlikely?

Quote:

Originally Posted by infinitesymphony /img/forum/go_quote.gif It depends which kind of noise you're talking about. Electromagnetic interference can be reduced by using higher-quality parts (power supply, motherboard, etc.), but in general, it can't be eliminated inside of a computer. If you're talking about fan noise, you can upgrade the fans, replace some of them with passive heatsinks, or install sound dampening material on the inside of the case. If the computer's power supply is electrically noisy or has ground loop issues, it's possible that the digital output could be affected. However, most sound cards have some filtering in place to reduce or nearly eliminate these power problems if they're present. An optical cable has a slight advantage in that it's not electrically coupled to the rest of the system like a coaxial cable. On the other hand, optical outputs are harder to implement, and many manufacturers don't do a very good job. Coaxial outputs are easier to implement because the transmission technique is electrical, just like an analog interconnect. So, take your pick.

The only difference between my and the ops problem that I have noise in my motherboards out as well. Back or front pane it's the same noisy.

 

[selkin]

some more from a laptom thread:

Quote:

Originally Posted by craiglester /img/forum/go_quote.gif I returned a dell for this very reason.. there was no way to completely eliminate the whine Apparently there's a problem with some core 2 duo laptop chipsets. Try over at notebookreview.com.. theres a few threads about it there.. Good luck

yeah this might be an option later imo.
Quote:

Originally Posted by derek8555 /img/forum/go_quote.gif you can definitely use some attenuator to attenuate the noise. The Shure one for $10-15 on eBay or anywhere else should be just fine.

I was wondering about this for a while before, don't know where should I start though, maybe this shure will do for a first try.
Quote:

Originally Posted by majid /img/forum/go_quote.gif Not sure an outboard USB DAC would fix your woes, you would need to use optical to guarantee electrical isolation.

so optical is better than coaxial in this regard.

 

[obobskivich]

holy triple posting batman

edit button for a reason champ


the noise is likely not RFI, but you're already mucked on that, so I won't bother trying to teach

as far as what makes a real high end PSU, PC Power & Cooling hands down, some of the better Seasonic units, the Enermax Galaxy series (far and away from what you've got), Antec introduced a new Signature series that showed some promise, never really followed up on it, things like that

honestly, the noise is either the 0202 (if its defective), the speakers themselves (never liked KRK, never considered them quality either), you've got crap ICs somewhere in the chain (i.e: non-shielded), you've got a ground loop somwhere in the chain, or your source media is at fault (i.e: its mastered with hum/noise, some records are like this)

the whole "RFI over USB" "EMI over USB", anyone understand what either of these concepts is? anyone understand a thing about USB? didn't think so.

 

[selkin]

the posts are differs from eachother

quotes from other similar threads.

rfi/emi over usb.... okay so pour some light into our darkness obobskivich then

anyway, the 0202 must be fully functional I've tryed different external usb card (maya44 usb) didn't really like it by the way. not to mention that the noise was there either. same with the motherboard's integrated soundcard.

I use an external source and everything is fine, no noise->> means KRK is out of the question. quality or not... I know it's not top-hot stuff but it is not a crap brand imo

could you tell me about ground loops, how can I eliminate this issue.

by the way, thanks for everyone's help so far

 

[obobskivich]

the 0202 IS an external device, so is the Maya44 USB, thats been my point all along, but apparently not even the person with the equipment in front of him gets that

as far as the RFI/EMI over USB, some members are claiming that shielded USB lines are carrying MASSIVE RFI/EMI interference (in the audible spectrum nonetheless), the reasons this generally can't happen include:

you'd have signal quality issues, as in, data wouldn't arrive
USB doesn't operate in the audible spectrum
theres shielded to prevent this
etc

if the speakers aren't the issue, and I wasn't saying KRK is a crap brand, but I was saying that I wouldn't be surprised if they were at fault (because they aren't super premium, some bad products do filter through), that leaves the ground loop thing, the source media thing, and the crap IC thing

unless of course, you've got really dirty power, which would be a sub-point to the ground loop thing

Let me google that for you

 

[selkin]

I like this letmegooglathatforyou thing

as for what do I get and what don't: sorry I try to do my best in english language. however this does not mean that from now on you should talk to me like you'd do to an infant

I did say that I have maya44 and 0202 both usb, both external and I'm very aware of this

regarded the noise over USB, I'm not really concerned about it as I'm almost 98% sure that the cards are OK. So I'll take my time, and discover this audible noise over USB issue later. ->> means it have to has a link to the computer->> groung loop ? nooo but as I said I'm not an expert on the ground loop issue.

source media: no way. I did write that I use mp3 player. do you think the files on my computer are different than on my mp3 player?
abxggk file from computer noisy, abbxggk file played from the mp3 player is clean. no matter what file I try->> means files are OK.

the last two things tha remains:

ground loop, dirty electricity: I don't think so, but yes I have to look into it. anyway I still think it's highly unlikely. As "If I drag things or move my mouse I get different sounds that are clearly corresponding to the actions on the PC too, though they are obviously not supposed to be there as they aren't real audio sounds such as the ones you actually get from clicking or anything like that."

crap IC: this is what I'm trying to change, and at this moment I think it's the Gigabyte p35-DS3l motherboard. I've already changed an older asus p4 mobo before though....

I really don't know tbh

 

[obobskivich]

by IC, i meant interconnect, not integrated circuit, sorry for that confusion

if you're getting audible noise from moving the mouse, as in the noise reacts to the mouse, that *is* noise from the PC, although you should not be getting that via USB (thats usually an issue found on very cheap integrated audio solutions (as we've been discussing in this and other threads) but shouldn't at all be an issue for USB solutions)

can you explain exactly how you've got everything connected?

 

[selkin]

Quote:

Originally Posted by obobskivich /img/forum/go_quote.gif by IC, i meant interconnect, not integrated circuit, sorry for that confusion if you're getting audible noise from moving the mouse, as in the noise reacts to the mouse, that *is* noise from the PC, although you should not be getting that via USB (thats usually an issue found on very cheap integrated audio solutions (as we've been discussing in this and other threads) but shouldn't at all be an issue for USB solutions) can you explain exactly how you've got everything connected?

nothing out of ordinary.
PC, LCD screen, keyboard (ps2), mouse (usb), emu 0202 soundcard (usb), minicack to mono jack Y cable to the mixer, mixer output: to mono jack for each krk (active) monitors.

pretty simple really. and again: I leave out the mixer and noise is just even more audible.

 

[obobskivich]

if you try another mouse, that isn't USB, what happens?

do you have any USB gadgets, like fans, connected?

 

[joe_cool]

I can't help but notice that both the mouse and the EMU are connected to the PC via USB, and that moving the mouse modulates the noise heard from the EMU.

I read a post from another head-fier who had this problem and he solved it by connection the EMU to a different USB port (on a card on the PCI bus).

I have seen this problem before on a USB-SPDIF coax converter. When I disconnected the USB ground (PC ground) from the output of the coax transformer the problem went away.

 

[selkin]

Quote:

Originally Posted by obobskivich /img/forum/go_quote.gif if you try another mouse, that isn't USB, what happens? do you have any USB gadgets, like fans, connected?

I tried usb to ps2 adapters.
no other gadgets or usb stuff.
all case fans are disconneted either.
CPU, RAdeon's and the PSU fans are the only ones switched on.

 

[obobskivich]

Quote:

Originally Posted by joe_cool /img/forum/go_quote.gif I can't help but notice that both the mouse and the EMU are connected to the PC via USB, and that moving the mouse modulates the noise heard from the EMU. I read a post from another head-fier who had this problem and he solved it by connection the EMU to a different USB port (on a card on the PCI bus). I have seen this problem before on a USB-SPDIF coax converter. When I disconnected the USB ground (PC ground) from the output of the coax transformer the problem went away.

thats where I was going with it

honestly I can't think of anything else to "cure" this, as its a problem I've never personally encountered, and I'm really surprised its actually happened in the first place

 

[selkin]

in this very moment as I read your replies I push the downarrow to scroll down in the forum. I'm not touching the mouse, only the ps2 keyboard and the noise gets lauder and stronger every time I push it. I push any other buttons on the keyboard I got exactly the same annoying clicking noise on the same volume.

how about that

 

[selkin]

ok got some update on this.
bought new motherboard, GPU, RAM, CPU and nothing.
bought a firewire audio interface (TC electronic Konnekt 24D), and the noise is gone.
happy days

now the only mistery that left is the reason why it's gone.
1: because the firewire cable that came with the device is just better quality (same would've happend with a better usb lead)
2: simply because it's firewire, not usb
3: the 24D has better parts than the emu 0202 (noise filtering?)
4: miracle baby, yes sometimes they happens.