Eliminating RFI


Dear All
I am experiencing problems for the first time with RFI through my Singlepower headphone tube amp. I have concluded that it is due to an unclean power supply as I do not pick up this interference using a wall plug in another room in the apartment and as I have also swapped out power cables and interconnects in the room to no effect. Most of my equipment is UK 240 volts and I run the mains (Brazil 110 volts) through the transformer to the equipment - however, I have never experienced any problems with this equipment - but as the headphone amp is 110 volts I am running it directly through the Brazilian mains (without the transformer) and I am now having problems.
Does anyone have any suggestions for me to eliminate this interference? I need to keep all my gear in this room so moving it all to another room is not an option unfortunately.
Many thanks
James
vicks7
Unfortunately not, although I am starting to think it is also airborne. When I was adjustimg my speaker cable by taping it to the floor (to stop it hanging in the air) the RFI seemed to reduce in strength. So, with a CD, Amp and Speakers I get the RFI through the speakers and if I plug a headphone amp straight into the mains with nothing else other than a headphone cable I still get RFI. Very frustrating. I am auditioning some Audiopax gear at the weekend and I have asked the dealer to bring some power conditioners as well to see if this helps.
Another idea that may or may not help: Ferrite cylinders that clip around your cables. Don't know for sure how much dynamic damping they cause. A pricey alternative to consider would be Z Sleeves by Z Cable. Here's a link to those:
Z Sleeves by Z Cable
I've never used them, only heard of them. Good luck and don't give up yet.
-Bill
A small "Faraday cage" may work. A Brass or copper screen box that would cover the encloser of your headphone amp. Thinking about it for a moment, I have seen various "metal" mesh containers and other "mesh" office supplies at Office Depot and even Wal-Mart. They are painted, so I don't know the metalurgy. I am certain that the stores would think not highly of anyone scraping the paint off of them before purchase, but they seem cheap enough. For a few bucks it might be worth a try.

Tubby
If you can find shorting plugs, try them in any unused inputs on your preamp. They are helping me w/similar issue. Cheers,
Spencer