2. tech-talk
  3. 1328289757

Shielding components from EMI/RFI... Help please

A recent experiment with a product designed to reduce EMI/RFI left me curious about other ways to reduce EMI/RFI in my system. In the past ten days, I've stepped onto a slippery slope, at the bottom of which is surely some kind of insanity...

I've been experimenting with copper plates in an effort to absorb, deflect, diffract, and block EMI/RFI. I've tried copper plates under components, on top of components, and inside components.

This is the point where you tell me I don't know what I'm doing and I'm likely to short circuit something and/or electrocute myself. Consider me duly warned. This is also the point where you tell me to get some balanced interconnects, or at least to get some shielded interconnects for Chrissake. Consider me duly informed. Moving on...

I'm hoping you can help me make the most of this experiment, and help me avoid killing a component or myself. My strategy so far has been to:

1. Place copper plates at locations that generate a lot of EMI/RFI, e.g., components with switching mode power supplies or high frequency clocks. The system has a total of 3 SMPS and 3 clocks.

2. Place copper plates at locations that are vulnerable to EMI/RFI, e.g., under the amp, near the transformer.

3. Place copper plates inside noisy components -- in particular, my Meridian G68 preamp/processor. I've begun to build 2 partial Faraday cages, one for the SMPS, and one for the analog output stage.

4. Ground the copper plates either to the component chassis (when plates are used inside a component) or to an independent ground point (when plates are used above/below a component).

Has anyone tried this sort of thing?

Bryon
bryoncunningham
bryoncunningham OP
893 posts
 
Hi Dave - Thanks for those links. They are very informative.

As far as A'gon rejecting your post because it was "too short," that is just strange. And arbitrary. My last post on this thread was two words long.

What's more, it seems like I've been hearing more and more A'gon stories of people whose posts are being rejected for one reason or another. Maybe there is new management in Moderatorland.

While I certainly understand the need to moderate forums for content that is truly objectionable, one of the things I always liked about A'gon is that it erred on the side of permissiveness rather than censorship. Not long ago, I joined another audiophile site, where 3 out of my first 15 posts were edited by a moderator. It was creepy. I stopped posting there altogether.

Whether it's in the virtual world or the real world, the excessive control of speech has a chilling effect on the exchange and progression of ideas. Let's hope this trend doesn't continue.

Bryon
bryoncunningham OP
893 posts
 
Update for anyone still interested in my adventures in EMI/RFI reduction...

Three more changes:

--I replaced the unshielded power cords for the power conditioner, the preamp, and the amp with shielded power cords. An improvement, even though I went from three $1100 cords (Shunyata Pythons) to three $100 cords (Pangea AC-9's).

--I added copper "sleeves" to the ends of all power cords in the system, as described here.

--I wrapped the external hard drive where my music is stored with TI Shield.

All three were improvements, but the biggest and most surprising improvement was wrapping the external drive with TI Shield. Don't know what to make of that.

FWIW.

Bryon
onemug
784 posts
 
Bryon,

Did the Pangea AC-9s change much after "x" amount of time?

Reason I ask is that I bought a few of them a year ago. I can't say anything bad about them but I found some cords I liked better. I just kept them because I'm too lazy to sell them. Now I need a cord and may give these a second chance. I didn't put many hours on them after I got them.

I admire your honesty in saying you liked them better than the more expensive ones.
bryoncunningham OP
893 posts
 
Yes, Onemug, I did notice a small improvement after they had about 100 hours on them. I am very impressed with the performance of the AC-9's. Remarkable for the price.

The fact that I preferred the very affordable AC-9's to the very expensive Pythons illustrates a point Al has made many times... in the world of cables, the correlation between price and performance isn't that strong.

Bryon
rodman99999
6,206 posts
 
"All three were improvements, but the biggest and most surprising improvement was wrapping the external drive with TI Shield. Don't know what to make of that." TI Shield has supernatural powers. That's why I personally recommend it. =;^)
More to discover