Digital, Coaxial and Interference
Oct 28, 2008 at 9:08 PM Thread Starter Post #1 of 21

punk_guy182

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I have bought the Belden 1694A Digital Audio Cable 15Ft from Blue Jeans Cable. My audio setup and the cables all work fine, but I have an issue with my source of sound. I use the digital coaxial output of my computer motherboard to play lossless audio files and I can hear all sorts of little sounds or interferences.
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The motherboard I am using is the Gigabyte EP45-DS3R. It also has an optical output and I was wondering if I switched to digital optical this would solve the problem. I was under the impression that the Belden 1694A cable is very sensitive and might pick up interferences that the optical cable would avoid.
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Oct 29, 2008 at 4:28 AM Post #2 of 21

pedxing

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Don't know much about cables, but have you tried your analog output off your motherboard? Sometimes the digital outs can be bad but the analog outs work OK.

In my experience, digital interference means you lose digital lock- the sound starts to skip or entirely drop. Really bad DAC solutions will play back blaring random noises and beeps, possibly blowing speakers out. If you hear hiss or fuzz, that might be interference coming from the amp.
 
Oct 29, 2008 at 7:59 AM Post #3 of 21

punk_guy182

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Okay! I'll check this out.

However, I hear more buzzing sounds when I scroll up and down with my mouse different programs with the mouse.
What is the source of the problem?

I have the ZERO DAC with OPA627AU and LT 1364 HP-preamp opamps
LD T_150 power amp.
 
Oct 29, 2008 at 1:40 PM Post #5 of 21

myinitialsaredac

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Okay to the OP try the optical, dont forget coaxial is moving electricity and is subject to the ground in your PC so you could be getting some nasty e.f.i. and ground noise. If this fixes it go with that. As to your more recent post it would make sense that a) your cpu is working harder i.e. drawing more electricity if its got speed step turned on or b) if your using asio 4all or foobar with wasapi then you may have to turn your buffer time up or down. Give those 2 a try, ie turn off speed step and mess with buffer time. But optical should remedy the first.

Dave
 
Oct 29, 2008 at 5:02 PM Post #6 of 21

punk_guy182

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Errrr!

Now I can't get a single sound with optical and I can see a red light coming out of the spdif output of my mb. Is there something I need to set to be able to get an optical signal?
I have just received this motherboard and never used optical before.
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I am using Foobar and WMP.

My cell phone is on top of my computer 4feet away from my ZERO DAC. The ZERO DAC has optical and digital input and is on top of my LD T_150 power amp.
I have SPDIF optical and coaxial outputs from the Gigabyte EP45-DS3R motherboard.

I'm really disapointed about my motherboard. I cannot get a clear digital signal via coaxial and I can't manage to get optical working. I don't know if the ZERO DAC or the mb is the source of the problem.


There is something I don't understand though. I don't hear those electrical signals when i use my senns HD595. and I only hear them with my power amp turned on through my speakers.
 
Oct 29, 2008 at 7:31 PM Post #9 of 21

Gollie

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While your MB has the sound option, I have never known anyone that has been satisfied with the sound. I would recommend something in the X-Fi family (either by Creative or Auzentech).
 
Oct 30, 2008 at 3:49 AM Post #10 of 21

punk_guy182

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I have the Auzentech X-FI Prelude and I wasn't satisfied by it. Besides that, I can't use it because there are no compatible drivers with Vista 64bit.
 
Oct 30, 2008 at 5:37 AM Post #11 of 21

pedxing

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Quote:

Originally Posted by punk_guy182 /img/forum/go_quote.gif
Errrr!

Now I can't get a single sound with optical and I can see a red light coming out of the spdif output of my mb. Is there something I need to set to be able to get an optical signal?



Sometimes there is switch in the drivers to make the sound go through the digital out. However, if you had a coax digital working, usually the driver sends the signal through both of them.

Quote:

Originally Posted by punk_guy182 /img/forum/go_quote.gif
There is something I don't understand though. I don't hear those electrical signals when i use my senns HD595. and I only hear them with my power amp turned on through my speakers.


I am assuming you are driving both from the DAC. If so, it sounds like an issue beyond the DAC like from the amp itself. I am wondering if you have like bad grounding with the amp.

If you own a GSM phone, 4 feet away may not be far enough. However, the interference should only appear from the cell phone when its communicating with the service such as an incoming text message or phone call.
 
Oct 30, 2008 at 5:46 AM Post #12 of 21

skamp

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What I'm wondering, is if your software setup mixes analog input with PCM audio, thus sending the mix to the S/PDIF output.

The Front/Headphone output of my old Terratec Aureon Sky 5.1 has some white noise (high noise floor), which gets worse when I activate the on-board headphone amplifier, and worse yet when I unmute the analog inputs. Its optical output doesn't suffer from it at all however, neither does the analog surround output.

I just don't see how the electrical noise from your PC could affect your S/PDIF signal, even with a coaxial link.
 
Oct 31, 2008 at 4:30 AM Post #13 of 21

punk_guy182

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Yes! I have solved the optical output problem. I have upgraded to the latest Realtek drivers and I can now use optical and coaxial out.
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I have also better configured audio properties in Vista 64 and I am using WASAPI to get a bit perfect signal and my onboard codec is bit perfect also.
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Although I have a little hum sound when the power amp in on. Can this be avoided if the DAC is at a certain distance?
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As for the buzzing sounds, they are unavoidable from what I have read in other posts and a soundcard couldn't fix the electrical signals coming frpm psu, cpu bus/pci.
I guess I'll have to live with that.
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The cell phone is turned off so that is not the source of the problem.
 
Nov 1, 2008 at 6:29 PM Post #15 of 21

myinitialsaredac

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It could theoretically make it worse KoKo, pci bus requires more power, so you have the potential of adding another ground loop and more E.F.I. The implementation of the digital on the cards in your comp are likely similar to the implementation to the digital on bigger sound cards.

Dave
 

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