3 ms·

If you're a bit handy, you can assemble a line filter using a part like this https://enerdoor.com/products/fin27/ https://enerdoor.com/products/fin27/ for a hec

by Gracana 11mo ago

If you're a bit handy, you can assemble a line filter using a part like this https://enerdoor.com/products/fin27/ https://enerdoor.com/products/fin27/ for a heck of a lot cheaper than you can buy a filtered power strip. You may also be able to solve the problem with a simple common mode choke, either the clip-on type, or a toroid that you wrap the cable through a couple-few times. https://palomar-engineers.com/rfi-kits/acdc-power-line-chokes https://palomar-engineers.com/rfi-kits/acdc-power-line-choke...

LM358 11mo ago
A filter like that will have very little attenuation in the audio spectrum. I agree however that indiscriminately throwing ferrites at problems can be a good solution!
- Gracana 11mo ago
  Maybe you’re right. My experience is with radios, where it’s possible that high frequency noise is conducted into the RF section rather than into the audio amplifier. I know that in one case, both my transmitted signal and received audio output were absolute garbage (edit: because it was picking up noise from the vehicle ignition) until I added a choke to the power input wiring.
- 0_____0 11mo ago
  This reminds me of my favorite "Downfall" meme video. [Youtube] "Hitler fails radiated emissions" - Orin Laney: https://www.youtube.com/watch?v=eeo8ZZTfwZQ https://www.youtube.com/watch?v=eeo8ZZTfwZQ
- mrob 11mo ago
  Even if there's very little audio-frequency attenuation, it's possible for higher frequencies to produce audio-frequency intermodulation distortion, and filtering could reduce this. This is one reason "high definition" (ultrasound sampling rate) audio is a bad idea as a listening format.
- actionfromafar 11mo ago
  Ferrites - almost never doing any harm, sometimes doing good. :-)
- vlachen 11mo ago
  In 2013 I bought out 2 Radio Shacks worth of ferrite beads when I was hunting down signal noise in my senior design project (CNC mill rebuild and update.) All else fails, add more beads. Also, I learned that you can make your own shielded flat cables with aluminum duct tape. Who knew that they had a really good reason for using 48V signaling in the original machine controls from 1986?

by Gracana 11mo ago

LM358 11mo ago

A filter like that will have very little attenuation in the audio spectrum. I agree however that indiscriminately throwing ferrites at problems can be a good solution!

Gracana 11mo ago
Maybe you’re right. My experience is with radios, where it’s possible that high frequency noise is conducted into the RF section rather than into the audio amplifier. I know that in one case, both my transmitted signal and received audio output were absolute garbage (edit: because it was picking up noise from the vehicle ignition) until I added a choke to the power input wiring.
0_____0 11mo ago
This reminds me of my favorite "Downfall" meme video. [Youtube] "Hitler fails radiated emissions" - Orin Laney: https://www.youtube.com/watch?v=eeo8ZZTfwZQ https://www.youtube.com/watch?v=eeo8ZZTfwZQ
mrob 11mo ago
Even if there's very little audio-frequency attenuation, it's possible for higher frequencies to produce audio-frequency intermodulation distortion, and filtering could reduce this. This is one reason "high definition" (ultrasound sampling rate) audio is a bad idea as a listening format.
actionfromafar 11mo ago
Ferrites - almost never doing any harm, sometimes doing good. :-)
vlachen 11mo ago
In 2013 I bought out 2 Radio Shacks worth of ferrite beads when I was hunting down signal noise in my senior design project (CNC mill rebuild and update.) All else fails, add more beads. Also, I learned that you can make your own shielded flat cables with aluminum duct tape. Who knew that they had a really good reason for using 48V signaling in the original machine controls from 1986?