Computer Noise

[DaveFloyd40]

Hi all,

First of all allow me to apologize if I am posting this in the wrong forum but it does relate to watching films, etc. through my Hi Fi.

Granted I am using an old system, a Quad 303/33 setup with Beovox 5700 speakers. It all sounds great, especially when playing a CD/DVD but as soon as I switch over to the computer I start to hear a high pitched noise. It's not loud but it does become louder the further I turn up the volume. It also depends on how much work the computer is doing as well. When I move the mouse about I can hear it through the speakers.

I have nothing fancy. Just a jack running from the PC which then plugs into the Tape input of the Quad 33 unit via left/right RCA. Yes, really simple but I honestly cannot remember having this issue when I was using my old Rotel amplifier. Is something inside the Quad unit picking up the noise from the PC or is it simply the cable?

Any suggestions and advice will be greatly appreciated. Thank you!

 

[faber12]

Try getting a USB sound card/DAC. The Sound Blaster Play 3 is inexpensive and sounds good.

 

[swechsler]

Try getting a USB sound card/DAC. The Sound Blaster Play 3 is inexpensive and sounds good.

The possibility still exists to transfer the computer whine over the ground connection. If a USB sound card doesn't solve the problem, the next easiest solution might be a USB to Toslink adapter to a DAC connected to the Quad. The fiber between the adapter and the DAC should prevent any computer noise from getting into your system.

But yeah, the sound cards built into most computers are pretty crappy. Always a good idea to eliminate them from the chain.

 

[whoaru99]

If the computer has a toslink or coaxial output using that into a DAC may eliminate the noise if it's strictly ingress into the analog section of the computer audio subsystem.

I've used optical/toslink to break ground loop hum but I didn't have the "computer noise" problem the OP has.

 

[swechsler]

I've used optical/toslink to break ground loop hum but I didn't have the "computer noise" problem the OP has.

If there's no analog circuitry in the computer, in theory there should be no way to get the noise from the computer to the amp, assuming, of course, that it's not coming in some other way (either via EMF radiation or through the power cords).

 

[whoaru99]

If there's no analog circuitry in the computer, in theory there should be no way to get the noise from the computer to the amp, assuming, of course, that it's not coming in some other way (either via EMF radiation or through the power cords).

Not clear your point. The OP says he's using analog output from the PC to his stereo.

 

[swechsler]

Not clear your point. The OP says he's using analog output from the PC to his stereo.

Right, my point was that the noise from the computer will necessarily be introduced in an analog circuit, not a digital one. So if you eliminate all analog circuitry in the computer by moving to a TOSLINK + DAC setup, and separate them via fiber, theoretically there's no way for the noise to make it directly to the amp.

 

[faber12]

The possibility still exists to transfer the computer whine over the ground connection. If a USB sound card doesn't solve the problem, the next easiest solution might be a USB to Toslink adapter to a DAC connected to the Quad. The fiber between the adapter and the DAC should prevent any computer noise from getting into your system.

But yeah, the sound cards built into most computers are pretty crappy. Always a good idea to eliminate them from the chain.

Ground loop does not usually respond to using the mouse.

 

[swechsler]

Ground loop does not usually respond to using the mouse.

Hmm, I missed that in the original post. It would be helpful to know the current arrangement of the OP's system (i.e. is the mouse close to the amp?). But again, if the noise is being induced into the analog section of the PC, using the toslink setup would fix it. If it's being picked up via EMF or line cord, another solution is probably in order.

 

[faber12]

I have a Dell Optiplex 390 that has a noisy integrated audio processor, it goes quiet when the CPU is under full load.

The Sound Blaster Play 3 was an inexpensive fix.

 

[KingBubba]

The switch to the USB/analog adapter is the way I went and I am hum/buzz free.

 

[David_NC]

I get noise from my wireless mouse through a cheap USB DAC that's powered from the PC's USB ports. When I use a better DAC with its own power supply, I have no noise. I haven't done enough troubleshooting to determine if it's the 5V power causing the issue, since I generally used the better DAC. This doesn't happen with all my amps or receivers, but it does with the one I'm currently using. I'm not sure if this is relevant or not; I only mention it due to the fact that noise can still be present with a USB connected DAC.

 

[DaveFloyd40]

Thank you all for your responses. I really appreciate your advice and ideas in troubleshooting this little audio issue for me. I have moved the computer as far from the Quad 303/33 units as is currently possible and when using the mouse it is nowhere near the amp or preamp. Oddly enough, I noticed that when using all the inputs on the back of the preamp (tape, radio 1, radio 2) the noise is noticeably louder. Especially when the DVD player is plugged into one of those inputs and removing the audio lead from the computer does nothing to alleviate that noise when in this configuration. When I remove the DVD connection to the Quad 33 unit then the "computer noise" quietens down again but does not disappear. Are the leads possibly picking up some sort of radiation (as has been suggested by "swechsler")? For the time being perhaps I should invest in some sort of external sound card and then go from there.

 

[spark1]

Thank you all for your responses. I really appreciate your advice and ideas in troubleshooting this little audio issue for me. I have moved the computer as far from the Quad 303/33 units as is currently possible and when using the mouse it is nowhere near the amp or preamp. Oddly enough, I noticed that when using all the inputs on the back of the preamp (tape, radio 1, radio 2) the noise is noticeably louder. Especially when the DVD player is plugged into one of those inputs and removing the audio lead from the computer does nothing to alleviate that noise when in this configuration. When I remove the DVD connection to the Quad 33 unit then the "computer noise" quietens down again but does not disappear. Are the leads possibly picking up some sort of radiation (as has been suggested by "swechsler")? For the time being perhaps I should invest in some sort of external sound card and then go from there.

Try an inexpensive USB DAC via Amazon. If it doesn't solve the problem, return it.

What operating system? Windows previous versions can be optimized for audio use, which may address at least some of your issues. I don't know if W10 requires similar tweaks, but I'm sure someone will jump in to answer.

 

[swechsler]

Especially when the DVD player is plugged into one of those inputs and removing the audio lead from the computer does nothing to alleviate that noise when in this configuration.

OK, this tells us that switching to an external DAC will probably not solve the problem (although I'd recommend it anyway; as I said earlier, the built-in DACs in most computers are sub-standard).

The next thing I'd try would be to run an extension cord from a different circuit (not just a different electrical outlet on the same circuit) and plug all your audio equipment into it (using appropriate outlet strips as necessary). Even better if it's on the other leg of your electric drop (this would depend on how your circuit breaker panel is wired). See if that affects the noise.

 

[DaveFloyd40]

Try an inexpensive USB DAC via Amazon. If it doesn't solve the problem, return it.

What operating system? Windows previous versions can be optimized for audio use, which may address at least some of your issues. I don't know if W10 requires similar tweaks, but I'm sure someone will jump in to answer.

Hi spark1,

I'm using good ol' fashioned Windows 7 Professional. I know I'm about a lifetime behind in terms of technology but this particular version has never failed me. I've tweaked various settings and reset, tweaked, reset, reset, tweaked countless time. Actually the onboard sound doesn't have much an output really. As I stated earlier the Rotel amp I was using didn't seem to pick up this "noise" like the Quad 303/33 system. I don't want to go back to the Rotel so I'll be purchasing an external DAC just to see if it makes any difference and if that still doesn't solve the issue then I'll give swechsler's suggestion a go.

 

[swechsler]

if that still doesn't solve the issue then I'll give swechsler's suggestion a go.

Might want to do it as a test first, although I agree that a DAC is definitely a worthwhile purchase.

 

[spark1]

Hi spark1,

I'm using good ol' fashioned Windows 7 Professional. I know I'm about a lifetime behind in terms of technology but this particular version has never failed me. I've tweaked various settings and reset, tweaked, reset, reset, tweaked countless time. Actually the onboard sound doesn't have much an output really. As I stated earlier the Rotel amp I was using didn't seem to pick up this "noise" like the Quad 303/33 system. I don't want to go back to the Rotel so I'll be purchasing an external DAC just to see if it makes any difference and if that still doesn't solve the issue then I'll give swechsler's suggestion a go.

I seem to remember when setting up a W7 laptop as a music player, there were settings to block system sounds and sounds from any app other than my media player (Foobar).

 

[JoeESP9]

I seem to remember when setting up a W7 laptop as a music player, there were settings to block system sounds and sounds from any app other than my media player (Foobar).

Select Exclusive when setting up WASAPI or ASIO in whatever music player you use. That turns off all Windows sounds while the music player program is active.

 

[twiiii]

I hate to mention this to all you PC owners, but I have 3 Apple computers. 2 iMac and one power book pro none of them give me any difficulties. The first i Mac is 10 years old, the mac book is 7 years old and the last iMac is 20 months old. So its not about the age.