Power grid interference: What does it look like measured with different tools?

DavidPiska

Well-Known Member
Jan 22, 2017
8
5
83
If you're interested to see what power grid interference looks like, take a look at the videos below, or a comprehensive article about it here: https://rdacoustic.cz/en/blog/2021/04/30/f4sx-audio-power-filter/ (explains in detail what I did here and includes background info + why is it important in audio). A few months ago, I posted measurements of power grid interference using a spectrum analyzer. Other measuring techniques include EMI line meters and oscilloscopes.

Measurements using an EMI meter:


Using an oscilloscope:


A closer look:


And using a spectrum analyzer:


This is Europe. I would be interested to see what it looks like on other continents if anybody has any measurements or experience. :)
 

Peguinpower

Member
Jul 22, 2021
38
26
23
54
This guy posted his own version of AC line noise test, and says he didnt see a difference in the actual output of a Topping D90 DAC. Im not impressed by this fella, the test if very narrowly focused, but its just as valid as your experiment.

 

Alrainbow

Well-Known Member
Dec 11, 2013
3,189
1,387
450
Without a reference how does this matter, ?
The filter shown is most likly loading the freq if the line noise centered on the measuring device shown . What other noise is there ? A person like ralph can explain better . Also if you cant see any change on a cheap toppings dac then it matters even less. Ps i own a toppings d90se lol
 

MaxwellsEq

Member
Mar 18, 2023
32
25
20
60
I would expect any competent electronic designer should be able to design solutions that reject electrical line noise. Perhaps some domestic audio kit has inadequate mains noise rejection, but professional studio kit would be thrown out if it couldn't handle mains-bourne noise properly.
 
  • Like
Reactions: Bso

Alrainbow

Well-Known Member
Dec 11, 2013
3,189
1,387
450
Amir has his own thoughts and is done very well. Now conclusions is of course to each there own
not all noise effects over all sound much be Measured. I’ve read many of his detailed articles he is spot on in what he does. It’s the effects that things get off the road for some.
I own the toppings it’s a very good dac in many ways
Now it’s no Lampi H or many others above it’s level of musicality
it’s a twinkle high detail sound. but if we dial it in to make it have more body it’s pretty good.
his view in sound I don’t always agree but no one does here.
 

Alrainbow

Well-Known Member
Dec 11, 2013
3,189
1,387
450
I would expect any competent electronic designer should be able to design solutions that reject electrical line noise. Perhaps some domestic audio kit has inadequate mains noise rejection, but professional studio kit would be thrown out if it couldn't handle mains-bourne noise properly.
Regulators remove noise but also add there own st times
Line noise reduction can be needed but most don’t
where line noise matters is any device that has a
Large gain phono pre for one
A pre amp not so much and an amp
Less still.
a dac is very complex and has many of its noises to deal with from all directions.
just sayhg
 

MaxwellsEq

Member
Mar 18, 2023
32
25
20
60
A mixing desk has high gain microphone stages dealing with low signals. Each channel has sequences of gain, attenuation, switching, gain, attenuation, switching etc.

Each stage has optimised power noise rejection.

If mixing desks were susceptible to mains-bourne noise, all recordings and broadcasts would have mains-bourne noise in them. But they don't. So this proves good designers can deal with power grid interference.
 
  • Like
Reactions: Republicoftexas69

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. This is THE place where audiophiles and audio companies discuss vintage, contemporary and new audio products, music servers, music streamers, computer audio, digital-to-analog converters, turntables, phono stages, cartridges, reel-to-reel tape machines, speakers, headphones and tube and solid-state amplification. Founded in 2010 What’s Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals, we enjoy learning about new things and meeting new people, and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing