Review on 10PCS RCA Noise Stopper Caps: Gold Plated RCA Connector Dust Proof Protector Cover by Mike Ewing

I bought several packs of these for my Krell HTS 7.1 preamp. I have a very high hum (16kHz?) on some inputs. It was heard from my chair which is 9 feet away from me. I figured it must be RFI or EMI, and they're cheap enough to try. To my surprise, they worked! I won't say anything fancy about the improvement in sound quality, but they did get rid of that annoying hum. The only time I heard it after installation was when I turned on the TV - and a lot less often. I used a coax cable for the Krell setup menu. And now that everything is set up with timing and balanced SPLs, I unplugged the coax. Now it's like a tomb in all the entrances. I still have a few deposits to make so I went ahead and ordered 2 more packs. So let's summarize this review. If you're having trouble with RF, this might help. When your system is quiet, you save money.