As mentioned, you probably have a ground loop going on there.
Your PC is already grounded through the power supply. If you connect its output to anything that has ANY kind of ground connection if its own, you will get a ground loop.
Typical sources for additional ground connections include: Radio and TV antenna, cable or satellite cables, other Class I (safety earthed) devices.
If you don't know where to start, connect one Class II (double insulated, 2-pole mains cable) amplifier and speakers ONLY. That should be quiet. Then start adding devices.
Your PC is already grounded through the power supply. If you connect its output to anything that has ANY kind of ground connection if its own, you will get a ground loop.
Typical sources for additional ground connections include: Radio and TV antenna, cable or satellite cables, other Class I (safety earthed) devices.
If you don't know where to start, connect one Class II (double insulated, 2-pole mains cable) amplifier and speakers ONLY. That should be quiet. Then start adding devices.
Thanks. Though there is nothing with a ground or any aerials connected to the PC, the PC's power lead is the only thing grounded; I've checked my amp and discovered it is double insulated too so no earth there either.
Following your suggestion I have tried disconnecting everything except the phono leads anyway though, just to see if anything was accidentally acting as an aerial, but its just the same. I'm now pretty certain this has to be something like blitter noise, as qusp suggested.
Thanks
Kev
Following your suggestion I have tried disconnecting everything except the phono leads anyway though, just to see if anything was accidentally acting as an aerial, but its just the same. I'm now pretty certain this has to be something like blitter noise, as qusp suggested.
Thanks
Kev
For me it was noise from the HDD seekking sequences but after changing everithing inside except HDD, DVD, Video Card, PSU and amplifier too the HDD noise wasn't there anymore! I cannot pinpoint anyother thing at this moment. It could still be your dilateted psu Jack plug hole, conection cable, and if you have anything like a TV amplified through your amplifier! That has made the thig for me once upponatime, even my PC was shutting down because of that!
Thats mysterious, this PC noise sounds like a really complex thing! I hope I don't end up swapping everything out like that.
I think I'll just try changing to an optical out to start with; that should get over any possible effects of ground loops or electromagnetics on the external wiring, and also more subtle things that would affect the analogue stage of the card but (hopefully) not its digital outputs. I'm hoping to borrow a DAC soon to find out... at least it will be a simple thing to try.
Cheers
Kev
I think I'll just try changing to an optical out to start with; that should get over any possible effects of ground loops or electromagnetics on the external wiring, and also more subtle things that would affect the analogue stage of the card but (hopefully) not its digital outputs. I'm hoping to borrow a DAC soon to find out... at least it will be a simple thing to try.
Cheers
Kev
like c'mon mate 50 pounds would make it out if or without making out with your equipment! I mean only if you are switching out from your sata 2 equip! you can con contact me through Kerulooszka@live@live.com same as skype
PC noise through internal sound card - solved
Well I got chance today to try an external DAC (a cambridge audio dacmagic plus). Connected it up with an optical digital cable from the S/PDIF out on my asus xonar essence stx card and cranked the amp up....so far so good.... started doing things on the PC.... nothing; no PC noises! Theres a slight hiss from the amp itself when the volume is near max but that's it
I tried it on a 5m long optical cable too; exactly the same. So it looks like another benefit will be in having longer runs on the digital signal part of my setup, and so keeping analogue and high power speaker cabling short.
One unrelated thing is that I left my old RCA lead connected so I can switch the amp between the dacmagic and the Asus card's analogue outputs. I'll have to do some careful listening but first impressions are that (in my system and having equalised the volume) I'd struggle to say which was being used aside from the PC noises. I believe the dacmagic plus goes for around £350 new, so it shows the DAC in the xonar card is pretty good if you don't get the interference I had.
Thanks for all the help in solving this!
Cheers
kev
Well I got chance today to try an external DAC (a cambridge audio dacmagic plus). Connected it up with an optical digital cable from the S/PDIF out on my asus xonar essence stx card and cranked the amp up....so far so good.... started doing things on the PC.... nothing; no PC noises! Theres a slight hiss from the amp itself when the volume is near max but that's it
I tried it on a 5m long optical cable too; exactly the same. So it looks like another benefit will be in having longer runs on the digital signal part of my setup, and so keeping analogue and high power speaker cabling short.
One unrelated thing is that I left my old RCA lead connected so I can switch the amp between the dacmagic and the Asus card's analogue outputs. I'll have to do some careful listening but first impressions are that (in my system and having equalised the volume) I'd struggle to say which was being used aside from the PC noises. I believe the dacmagic plus goes for around £350 new, so it shows the DAC in the xonar card is pretty good if you don't get the interference I had.
Thanks for all the help in solving this!
Cheers
kev
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Another update for anyone finding this thread: I got the chance to try a digital coaxial cable tonight - for me at least it works equally well as the optical one in avoiding the PC noises.
So as theres still a ground connection to the same place, in my case it seems a little less likely to have been ground loop issues to/with the power amp; combined with the amp having no ground connection either I'd be inclined to suspect something else.
It doesn't mean that there weren't electromagnetic effects on the cable, since although this one is also electrical it is (a) digital so better at rejecting subtle interference and (b) a different cable so may have better shielding. It probably doesn't dismiss electrical or electromagnetic interference affecting the sound card either, since by staying digital until later down the chain I've still bypassed the card's analogue output stage, which would have been more affected by such things in and around the PC.
Cheers
kev
So as theres still a ground connection to the same place, in my case it seems a little less likely to have been ground loop issues to/with the power amp; combined with the amp having no ground connection either I'd be inclined to suspect something else.
It doesn't mean that there weren't electromagnetic effects on the cable, since although this one is also electrical it is (a) digital so better at rejecting subtle interference and (b) a different cable so may have better shielding. It probably doesn't dismiss electrical or electromagnetic interference affecting the sound card either, since by staying digital until later down the chain I've still bypassed the card's analogue output stage, which would have been more affected by such things in and around the PC.
Cheers
kev
Hi Kev06,
In my specific case, it turned out, that the culprit was the PC power supply (Thermaltake TT-450NLINH-1, PN W0276). The poor quality PSU has been replaced with Seasonic S12II-520W 80+Bronze PSU. Now, the noise level dropped by -15dB.
Looks like there are other major areas you need to look into.
PSU – compare for ripple and noise
Roundup: 12 Gaming Power Supplies Compared - New Tests: Ripple And Noise
BIOS.
Possibly disable C1E and E1ST ("speedstep"). Also Set PCI Latency Timer to
higher value.
Windows OS.
Enhanced Intel SpeedStep® Technology - How To Document
http://www.native-instruments.com/knowledge/questions/847/Windows+7+Tuning+Tips+\
for+audio+processing
Gain structure.
The sound level coming out of your sound card, should be set to maximum, therefore you will utilize the SNR of your sound card to the full range. This may overdrive your amplifier input, so if this is the case, you my need to insert a resistive attenuator between the sound cards output and amplifier input.
Ground loops.
You have already discarded those.
Best Regards,
Bohdan
Thanks for the thoughts, I'll certainly look at the BIOS and windows tweaks you suggested, much to learn!
TBH I'd feel cautious about swapping PC hardware out by this stage though, because it seems the cause of the PC noises has so many possibilities (PSU, graphics card, sound card etc) that it could get quite expensive trying to eliminate it. An external DAC would cost too, of course, but I now know that it absolutely solves the problem (in my case anyway), so would be a much more certain return for my money.
I've also got on surprisingly well with the borrowed dacmagic plus; I've been using it like a pre-amp and its got some other benefits (in addition to solving the PC noise), such as selecting different digital sources (like my TV) and offering a digital mute/volume control. Not sure how that would compare in sound quality with the Jriver's software volume control, but I'll be needing 'some' form of volume adjustment when I swap to active speakers.
Cheers
kev
TBH I'd feel cautious about swapping PC hardware out by this stage though, because it seems the cause of the PC noises has so many possibilities (PSU, graphics card, sound card etc) that it could get quite expensive trying to eliminate it. An external DAC would cost too, of course, but I now know that it absolutely solves the problem (in my case anyway), so would be a much more certain return for my money.
I've also got on surprisingly well with the borrowed dacmagic plus; I've been using it like a pre-amp and its got some other benefits (in addition to solving the PC noise), such as selecting different digital sources (like my TV) and offering a digital mute/volume control. Not sure how that would compare in sound quality with the Jriver's software volume control, but I'll be needing 'some' form of volume adjustment when I swap to active speakers.
Cheers
kev
Looking at xonar pics I cannot locate the SPDIF isolation (pulse) transformer. Could it be integrated into the cinch female connector which is larger than the other two on the board? If it is the case, the SPDIF link is galvanically isolated just like the toslink one.
TBH I'm not sure; I bought the card more on reviews than any great understanding of its topography. Certainly the digital connector is one of those combined RCA/optical jobs and it would seem reasonable (to me) to isolate at or in the connector. The other two RCAa are for the analogue out.
Cheers
Kev
Cheers
Kev
I got very obvious noise through computer earphone port before on a DIY computer. I can hear hard-drive activities or the computing process changes through earphone, so I figured that the noise related to the current computer consuming, it must be ground related inside the computer. I found the earphone port has two ground, one thought earphone cable, one through chassis, I cut the ground connection through chassis, it became much quieter. I can no longer hear any heard drive or process changing activities through earphone.
Yeah, some front panels are messed up like that right from the factory, unfortunately. Gives a first-rate ground loop, as you found. Disconnect the extra grounding through the case so that only the audio ground from the ribbon cable remains connected to headphone jack ground, and the noises miraculously disappear the way they did here.
Note that there are some differences between AC97 and HDA front panels. HDA shares a single ground return for both headphone out and mic in, which must be kept separate from case ground at the front panel. With the front audio cable unplugged at the mo/bo there must not be any continuity from headphone ground to case - should be easy to check. If there is a connection, you have to look at the panel and devise a way of separating things. If there is a big ground plane or anything, it would be nice if most of it remained connected to case ground for EMI reasons.
That Blitter Noise !
Kev,
I can confirm the optical out solution works perfectly but a pain that it doesnt solve the actual original problem !
Had EXACTLY the same NOISE (blitter scratching, pulsing) coming out of my speakers. Both via the Anaologue outputs from the PC into my preamp and also via the USB out into my Sonar Vstudio Dac audio interface which then feeds into the preamp. In fact even with the preamp and power amp off I could still get the noise coming through until I disconnected my USB lead to my DAC. The noise is totally related to pages loading, scrolling the mouse across the screen and any computer activity. Worse were some internet pages like You Tube and Amazon, you could just sit there listening to the noise !
So ! I disconnected the Analogue audio to my preamp. I disconnected the USB out from my PC into my Sonar Dac and ALL QUIET. And so it should !
Pulled out my Edirol FA101 ( as that has an optical input which unfortunately the Sonar doesnt), connected it all up to the PC and Silent as a Baby ! No more noise and scratching and listening to pages loading up etc etc.
Fantastic that it is lovely and quiet but would love to have found out the problem. I am using the inbuilt Motherboard Soundcard and Video an ASUS Z87A and it wasnt cheap ! Did consider getting a separate Graphics Card but to see if that was the culprit but its an expensive way if it wasnt, so opted for what I had around. If anyone else does come up with another cheap solution please let us know ! Best Regards Paul
Kev,
I can confirm the optical out solution works perfectly but a pain that it doesnt solve the actual original problem !
Had EXACTLY the same NOISE (blitter scratching, pulsing) coming out of my speakers. Both via the Anaologue outputs from the PC into my preamp and also via the USB out into my Sonar Vstudio Dac audio interface which then feeds into the preamp. In fact even with the preamp and power amp off I could still get the noise coming through until I disconnected my USB lead to my DAC. The noise is totally related to pages loading, scrolling the mouse across the screen and any computer activity. Worse were some internet pages like You Tube and Amazon, you could just sit there listening to the noise !
So ! I disconnected the Analogue audio to my preamp. I disconnected the USB out from my PC into my Sonar Dac and ALL QUIET. And so it should !
Pulled out my Edirol FA101 ( as that has an optical input which unfortunately the Sonar doesnt), connected it all up to the PC and Silent as a Baby ! No more noise and scratching and listening to pages loading up etc etc.
Fantastic that it is lovely and quiet but would love to have found out the problem. I am using the inbuilt Motherboard Soundcard and Video an ASUS Z87A and it wasnt cheap ! Did consider getting a separate Graphics Card but to see if that was the culprit but its an expensive way if it wasnt, so opted for what I had around. If anyone else does come up with another cheap solution please let us know ! Best Regards Paul
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