Welcome to the AudioShark Forums.
Results 1 to 3 of 3
  1. #1

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

    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: F4SX Audio Power Filter - RDacoustic.cz (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 with and without a power filter 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 sample measurements or experience.

  2. #2
    Senior Member
    Join Date
    May 2017
    Location
    Cleveland, Ohio, USA
    Posts
    442

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

    The only place these trivial AC line irregularities have any impact is at the audio output of your components.
    An well designed component will be able to deal with much larger irregularities.
    If fact if you were to examine the AC power in to your amp with a current probe, you would see that the amp converts those pretty sine waves in to almost square waves.

  3. #3

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

    Quote Originally Posted by Speedskater View Post
    An well designed component will be able to deal with much larger irregularities.
    A filter suppresses high frequency interference that comes from the power grid. The vast majority of audio components rely only on a simple transformer in the source section. However, due to its parasitic internal capacitance, high frequency interference gets from the source part to the signal. Most electronics then address this with a strong feedback loop, which diminishes the detail we were looking for in music in the first place.

    Quote Originally Posted by Speedskater View Post
    If fact if you were to examine the AC power in to your amp with a current probe, you would see that the amp converts those pretty sine waves in to almost square waves.
    Absolutely, but this happens at 50–60 Hz, 100–120Hz if you want: I don't know what this has to do with high frequency interference that is the subject of our article. Speaking of amplifiers and your "square waves"... the area of interest here is at the edges where interference occurs at the switching diodes. This interference, which is in the DC part already, is addressed by hardly any manufacturers. If only, among others, because in the DC part, the solution would have to be large and expensive.

    We go for details in music, so we use high sensitivity drivers that are capable of reproducing those details. With low-sensitivity speakers, or when someone uses equalization, for example, such details obviously won't be audible. Whether discarded by strong feedback in the amplifier or anything else, doing this kind of thing will loose sense. But there's no doubt it makes sense in our audio chain...

AudioShark - The Best High End Audio Discussion forum.

AudioShark forum is a leading forum site for High End Audio Discussion, Stereo System Discussion, Home Theater System Discussion, Best Home Stereo System Discussion, Home Theater Installation Discussion etc.

The AudioShark forum was created for sharing the passion of high-end Audio. We have Audiophiles from all over the world participating and sharing their knowledge. From novice to experts, you will find a friendly environment for discussing about High End Audio, Stereo System, Home Theater System, Home Stereo System, Home Theater Installation, Amplifiers, Speakers, Subwoofers, Integrated System, Acoustic treatments & Digital Room Corrections and many more.

At AudioShark, we also have incorporated an exciting Marketplace where members can peruse terrific buys on used gear, as well as meet dealers and discuss the purchase of new gear.

We are as crazy about this hobby as you are! So come on in and join us! Audioshark.org the Friendliest Audio Forum!

Industry Participation Disclosure : The owner and administrator of Audioshark is the owner of Suncoast Audio LLC in Sarasota Florida. Suncoast Audio has a full brick and mortar presence in Sarasota with several great show rooms with many world class brands. More information can be found at http://www.suncoastaudio.com

Audioshark is a community of like minded individuals. Audioshark welcomes participation from all manufacturers and owners of all brands and products. It is our belief that online forums provide a community of like minded audiophiles and music lovers to encourage the growth of this wonderful hobby.

Sincerely,
The Audioshark.org Team

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

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •