Testing Open Power Cord interference in Interconnect Cables (video)

Vive le dissonance!

Member
For anyone who likes reading, this Wikipedia article isn't too bad at explaining the phenomenon (however, I am unable to vouch for every detail in the article; I simply don't know enough.) Among other things, the math isn't too difficult to understand.

I finally found the twelve minutes of time to watch the video. Amir as always comes across as rather avuncular, even charming, and for that reason as much as any it's a fun video. I remain surprised anyone who claims to be knowledgeable in the field isn't already aware of parasitic capacitance literally from common experience, but Amir says it's not rare and I believe him.

However, I can't help but think that the essential content of that 12-minute video could have been consumed by me in a written format (perhaps with miniature video demos embedded) in under a minute. As such, I hope Amir continues with his written reports, essays, and reviews.

dtaylo1066

Senior Member
So you are saying I should not have my \$275 per foot speaker wire or \$500 per meter, extra-long interconnects wrapped around or taped to my \$600 power cord? What if I put in a power conditioner, will that help?

OctoEmu

Member
Amir's thumbnails are always spot on!

wwenze

Addicted to Fun and Learning
I may be poking my nose into this but two main key pointers for people too busy to watch the video

1) Airborne interference is real and measurable (First part of measurements)
2) It also contains very little energy so if you have something to suck it up i.e. most practical equipment would have an input impedance of <1Mohm and an output impedance of very low, the amplitude drops to below noise floor (Second part of measurements)

restorer-john

Master Contributor
@amirm your video, when you loopbacked the cable, it was locking onto a ~10kHz dominant frequency on each channel. Is that an internal 'birdie' or something else? At less than a uV, it's amazing it can find anything.

RayDunzl

Grand Contributor
Central Scrutinizer
I can't help but think that the essential content of that 12-minute video could have been consumed by me in a written format (perhaps with miniature video demos embedded) in under a minute.

There's this:

That gives this:

Extemporaneous speech can be a bit of a difficult read, though.

Oh cool, you can click on the text and it jumps to that point in the video.

What will they think of next?

Last edited:

AndreaT

Senior Member
Forum Donor
Great video! It reminds me that AC electrical cables not terminated in their receptacle of the audio equipment do behave like emitting antennas, radiating an electro-magnetic field. Back in the days of early HDTV, I struggled to get some understanding of antenna theory, dreaming of building rhombic antennas and looked into the superb Kathrein-Scala PR-TV and did not dare to buy it…Thank you Amir!

AndreaT

Senior Member
Forum Donor
Here!

From: John D Kraus. Antennas (1950).

Newman

Major Contributor
My entries for the inevitable captioning contest:

"Needs less Jalapeño..."
"Hi Amir, I'm turning on the mains power NOW!"

Pugsly

Member
My entries for the inevitable captioning contest:

View attachment 215418
"Needs less Jalapeño..."
"Hi Amir, I'm turning on the mains power NOW!"
Huh, what is that speaker on @amirm 's left shoulder that is just about touching his hand? In all seriousness, I think it would be good to just outright begin the video with a fair-use clip, and then respond directly by saying that you are using this as an opportunity to explain/educate. Danny's game of 'you-know-who-I-am-talking-about-but-I-won't-say-it-outright' was juvenile, so why respond in kind and sink to his level? Just my 2 cents...

Technical Expert
Forum Donor

pma

Major Contributor
I'm going to be contrarian guy and say I'd rather read it. I love reading, and for me reading is way, way faster than the time a video of the same content requires.
Totally agree. Videos mostly promote the author himself and are time consuming. However, it is trendy nowadays, when people get more and more lazy to study anything in deep.

OP

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
@amirm your video, when you loopbacked the cable, it was locking onto a ~10kHz dominant frequency on each channel. Is that an internal 'birdie' or something else? At less than a uV, it's amazing it can find anything.
I didn't pay attention at the time. I should see if there is some source of that some place....

tomtoo

Major Contributor
My entries for the inevitable captioning contest:

View attachment 215418
"Needs less Jalapeño..."
"Hi Amir, I'm turning on the mains power NOW!"

I disconnected the klippel but this loud anoying beeep---beeep---beeep is still there?

xaviescacs

Major Contributor
Forum Donor
My first reaction: another guy explaining EM with invisible capacitors...

My second reaction:

Trdat

Addicted to Fun and Learning
Forum Donor
I'm going to be contrarian guy and say I'd rather read it. I love reading, and for me reading is way, way faster than the time a video of the same content requires.
Im with you, don't have time for videos. A simple test result with a written conclusion in best.

Easternlethal

Member
Forum Donor
Brilliantly timed video. Out 1 day after Danny's attempt to ridicule the test

DSJR

Major Contributor
Huh, what is that speaker on @amirm 's left shoulder that is just about touching his hand? In all seriousness, I think it would be good to just outright begin the video with a fair-use clip, and then respond directly by saying that you are using this as an opportunity to explain/educate. Danny's game of 'you-know-who-I-am-talking-about-but-I-won't-say-it-outright' was juvenile, so why respond in kind and sink to his level? Just my 2 cents...
Didn't you see the little Neumann monitor alongside though (I should be more observant as to what the Neumann is sitting on, sorry)?

tomchris

Active Member
Great! Love to see a video on grounding issues in cases such as a) vibration/tingling sensation when touching metal surfaces and b) USB DAC to amplifer problems.

Last edited:

Replies
33
Views
6K
Replies
112
Views
14K
Replies
11
Views
1K
Replies
542
Views
37K
Replies
617
Views
54K