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Small PC vs streamer

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#21
There are other ways to test for noise other than using the dac output.
Since the DAC output is what is going to be fed into the amp, and thence to the speakers, the DAC output is a good place to look for 'noise' that may impact on the sound quality.

What other ways for testing for 'noise' are you proposing? A LISN, to check for conducted susceptibility? Something else?
 

amirm

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#22
So you say unequivocally, this cannot improve sound quality?
In almost all cases, yes. I will offer $200 for anyone who runs a controlled blind listening test that shows otherwise.
 

rebbiputzmaker

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#23
Since the DAC output is what is going to be fed into the amp, and thence to the speakers, the DAC output is a good place to look for 'noise' that may impact on the sound quality.

What other ways for testing for 'noise' are you proposing? A LISN, to check for conducted susceptibility? Something else?
IMO the smarter way is to check for and (hopefully subsequently) reduce noise is start at the beginning. In most cases that would be the wall outlet. Grounding or sometimes not grounding (floating) certain items. In some cases. Isolation (i.e. transformers) for sensitive devices. etc. Try making the environment as clean as possible.
 

amirm

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#24
IMO the smarter way is to check for and (hopefully subsequently) reduce noise is start at the beginning. In most cases that would be the wall outlet. Grounding or sometimes not grounding (floating) certain items. In some cases. Isolation (i.e. transformers) for sensitive devices. etc. Try making the environment as clean as possible.
Unless you are measuring the output of the audio system, you have no idea if you are making things better or worse. I have tested a number of such tweaks and many actually increased noise despite the lay understanding that they lower it.

So let me repeat: you must measure. We can measure noise. If you don't measure it, you are fooling yourself.
 

rebbiputzmaker

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#25
In almost all cases, yes. I will offer $200 for anyone who runs a controlled blind listening test that shows otherwise.
Yes people do gamble with their religious beliefs all the time! Oh God please give me the winning lottery numbers.
 

rebbiputzmaker

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#26
Unless you are measuring the output of the audio system, you have no idea if you are making things better or worse. I have tested a number of such tweaks and many actually increased noise despite the lay understanding that they lower it.

So let me repeat: you must measure. We can measure noise. If you don't measure it, you are fooling yourself.
There is no proof the noise you measured is audible. . Very respected people feel this way.. Not everything measured is audible, not everything audible is measurable.
 

amirm

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#27
There is no proof the noise you measured is audible. . Very respected people feel this way.. Not everything measured is audible, not everything audible is measurable.
No, you are describing an electronics process and effects that are measured everyday of the week and twice on sunday in design and verification process.

People doing such work should use some other terminology like reducing planktons and such as to not be subject to this type of back and forth. The moment you embark on using technical terms, you better know what they mean.

BTW, I hope you know your arguments are not fresh to us. We have heard all of this before and repeating it is not useful. We know those people think they are hearing the effects of reduced noise. It is just that their perception is driven by misunderstanding of the technology and improper testing.
 

amirm

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#28
There is no proof the noise you measured is audible.
On the contrary. We apply psychoacoustics to them and easily determine that they are not audible. We combine measurements and science of hearing which is based on listening tests to arrive at durable conclusions.
 

rebbiputzmaker

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#29
No, you are describing an electronics process and effects that are measured everyday of the week and twice on sunday in design and verification process.

People doing such work should use some other terminology like reducing planktons and such as to not be subject to this type of back and forth. The moment you embark on using technical terms, you better know what they mean.

BTW, I hope you know your arguments are not fresh to us. We have heard all of this before and repeating it is not useful. We know those people think they are hearing the effects of reduced noise. It is just that their perception is driven by misunderstanding of the technology and improper testing.
On the contrary. We apply psychoacoustics to them and easily determine that they are not audible. We combine measurements and science of hearing which is based on listening tests to arrive at durable conclusions.
Just to be clear, my aim is not to go back and forth on subjects such as this. In fact it is not "fun" which seems to be a word that you placed so prominently in your subtitle.

Oh and just to clarify an earlier post, there are tools to measure noise, other than measuring the dac output. I have been doing this for years.

BTW; when you say "we" who is we?
 
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amirm

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#30
Oh and just to clarify an earlier post, there are tools to measure noise, other than measuring the dac output. I have been doing this for years.
Do the researchers you mention used those tools? If so, you have a link?
 

rebbiputzmaker

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#32
Do the researchers you mention used those tools? If so, you have a link?
I was speaking on what I use, and yes, other people also do things like measure noise at the outlet, etc.

How do you classify "researcher" Can audio industry professionals be considered researchers? Dedicated hobbyist?

So now that you have clarified the "we" what makes some of the people that have migrated here different others? I really hope that you do not think that anyone with different thoughts than the "we" here are clueless. I do understand you think that "I" am lol. But that cool with me.

And I have not had much contact with plankton, except when watching Sponge Bob with the kids.

Sheldon J Plankton
 

rebbiputzmaker

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#34
Would you like to enlighten us as to what these tools are? You never know, we may even agree with you.
To start, as far as AC noise I have an old Entech noise monitor, not the end all be all but very helpful. There are of course better, professional meters, or by using a scope etc, to test for AC noise. Here is thread from CA with a bit more info. There are other threads on Ethernet switches are proper grounding that some may find helpful. As far a USB, I have not for the the longest while used power from a MB to power a DAC or connected device. You can buy or make a split USB cable, use a PCI card that can be power by a linear supply etc.

I hope that trying to deal with noise in one's environment does not cause angst for some.

https://www.computeraudiophile.com/...oise-monitor-meter-quotthe-noise-snifferquot/
 
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#35
or by using a scope etc, to test for AC noise.
If you can see noise on a scope, it will be much higher level than the noise floor measured with a spectrum analyser, and you have serious problems, wherever you measure it in the audio path. It's the wrong instrument for the job.

Yes, mains has noise on it, from many sources. And your entec meter may be able to measure some of it (not sure why they chose 300k to 700k, though).

But a decent power supply should filter the noise. If you can't see the noise on the DAC output, measured with a suitably sensitive instrument, then the DAC PSU is doing its job.
 
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Fitzcaraldo215

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#36
To start, as far as AC noise I have an old Entech noise monitor, not the end all be all but very helpful. There are of course better, professional meters, or by using a scope etc, to test for AC noise. Here is thread from CA with a bit more info. There are other threads on Ethernet switches are proper grounding that some may find helpful. As far a USB, I have not for the the longest while used power from a MB to power a DAC or connected device. You can buy or make a split USB cable, use a PCI card that can be power by a linear supply etc.

I hope that trying to deal with noise in one's environment does not cause angst for some.

https://www.computeraudiophile.com/...oise-monitor-meter-quotthe-noise-snifferquot/
Sounds like fun, but you are losing me.

Was it not you who recently raised the question of audibility? So, if you want to make reductions in noise that are audible, they have to be put through a system, amp and speakers, a room and finally your ears. If audibility of noise is a concern, why are you measuring the AC at the wall? Should you not be measuring at least at the DAC's output to the amp and speakers, since there is a high likelihood that the system may filter any noise in the AC, rendering it inaudible? Why mess with the AC if it does not create an audible difference or at least a measurable difference as it leaves the DAC or amp? No, you may say, but you are measuring arse backwards if noise is truly a concern. And, you have mentioned no measurements at the business end, closer to the ears, to really know one way or the other.

But, have fun measuring the AC, useless as that may be. You seem to have some rituals aimed at something or other with no idea what you are actually doing, cool though it might sound.
 

rebbiputzmaker

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#37
Sounds like fun, but you are losing me.

Was it not you who recently raised the question of audibility? So, if you want to make reductions in noise that are audible, they have to be put through a system, amp and speakers, a room and finally your ears. If audibility of noise is a concern, why are you measuring the AC at the wall? Should you not be measuring at least at the DAC's output to the amp and speakers, since there is a high likelihood that the system may filter any noise in the AC, rendering it inaudible? Why mess with the AC if it does not create an audible difference or at least a measurable difference as it leaves the DAC or amp? No, you may say, but you are measuring arse backwards if noise is truly a concern. And, you have mentioned no measurements at the business end, closer to the ears, to really know one way or the other.

But, have fun measuring the AC, useless as that may be. You seem to have some rituals aimed at something or other with no idea what you are actually doing, cool though it might sound.
Because the correct thing to do is to provide a clean environment, start at the beginning. Just like following proper infection control procedures in a health care setting. Sorry if this is foreign to some.
 

Wombat

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#38
Indeed the correct procedure is for the noise levels to be measured throughout the system by someone skilled in doing such. If the cause can be shown to be your mains supply and not your equipment then contact your power utility. They will investigate and address the issue if it exceeds their interference Standards. Amateurs playing around with mains and equipment earthing arrangements is a foolhardy behaviour that can be dangerous and likely to be illegal. At the least your home insurance will be void. :rolleyes:
 

rebbiputzmaker

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#39
Indeed the correct procedure is for the noise levels to be measured throughout the system by someone skilled in doing such. If the cause can be shown to be your mains supply and not your equipment then contact your power utility. They will investigate and address the issue if it exceeds their interference standards. Amateurs playing around with mains and equipment earthing arrangements is a foolhardy behaviour that can be dangerous and likely to be illegal. At the least your home insurance will be void. :rolleyes:
One of the more funny things I have read lately, thanks for the laugh though. Then you bring in the DANGER DANGER WILL ROBINSON! Thanks! :)

Don't know about where live but if you call a utility where I live and tell them you have noise on your AC line from yours or neighbors appliances, refrigerator, air conditioners, neaby RF... yada yada yada. After they finish laughing, they will say what do you want us to do buddy?

How is plugging in a filter, or isolation transformer dangerous or illegal??? How is using a linear PS instead a noisy switcher foolhardy. Amir just mentioned in his latest dac tests he will be using a linear supply for his Exasound DAC.

 
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#40
Sorry if this is foreign to some.
Measurement and diagnosis of problems isn't foreign to me. Neither is power supply design, or EMC compliance testing.

But I'd only start looking for supply problems if they were having an effect downstream, on the audio. Then I'd start looking at the filtering on the mains input of the power supply, and if my mains supply had significant disturbance.

Mains noise is primarily caused by large power loads, switched by electronic switches. You are unlikely to be able to do much about those. But if you can detect that such noise is discernible at the audio output, add additional filtering to the mains input of your relatively low power audio devices; filtering low power loads effectively is easy.
 
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