RF filtering [Archive] - Audio & Video Forums


View Full Version : RF filtering

03-28-2010, 06:15 AM
On a line level input some RF noise can forward to PREamp. Nearly all of the manufacturer protect just the hot pin from this kind of signal. But the shield of line (connector) can work like antenna. For example if I plug the tuner at power off state to amp the the CD sound quality is go down. The problem is the same if I plug the LP player (with MC transformer) to amp.
:20: The only reason is the RF interference go trough the shield of line input and make garbling in the internal signal of the amp.

So anybody know some magic box to filter RF signal from hot and shield point of RCA line connector?

04-06-2010, 11:31 AM
See solutions at diyaudio "RF filtering"...

04-06-2010, 06:36 PM
So you have RF problem with CD player as well?
If you are having a problem with analog tuner and TT setup, try moving/lifting RCA wires.

You might want to check all the RCA wires for damage. Have you swapped out for a different pair of RCA wire? Also, clean your RCA connectors on your preamp.

Stillpoint ERS cloth has helped me alot, but the biggest improvement I had for my TT setup was by moving MC Step up Transformers and wires to different location. Moving 5 inches or turning the device 90 degrees can sometimes have large impact on RFI.

The best thing to do is Try, Try, and Try. But of course your problem might be different from mine.


04-06-2010, 06:41 PM
I've tried tons of Ferrit Core Blocks and they have helped a little.
It might work for you, but if it's analog related problem then I would suggest you try different RCA cable locations.

04-13-2010, 10:19 AM
I'm sure all cable is fine.

I have problem with CD/DVD, LP (MC) and tuner and sat receiver too. But remeber we talking about very small difference if we measure with ears of avarage peoples. For me of corse this is dramataical...

But maybe the special location of my apartment is important. I'm at roof level of 2M city. So may radio transmission arrived to my system.

:10: From technical side this small tricks has basic. The nearly 20m long shield cable linked together is theoretically (and practically) source of many radio interfenece. I wondering why the manufacturers does not think about.

To play with position of equpments is very dangerous. For example during the day the radiation direction always cahged (refelxions, mobile phones, etc.). The best way to find solutuion for any postion. This guarantee for auqlity aution and video reproduction...