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Best Cable for canceling RFI

Problem:
WAY too much rfi interferance from local broadcast FM radio signal.

System:
Jolida 302a Integrated Amp, Castle Acoustice Richmonds, Rega Planet 2000 CDP, Kimber 4pr speaker cable. DIY power cable.

I have tested everything and all interconnects disconnected

I am getting an identifiable signal from a local FM radio broadcast - 91.5 Brooklyn New York - SUNY rebroadcast of foreign radio - when nothing but my amp plugged into the outlet.

I build my own power cable - Shielded Belden Cable with Shurtere IEC and Marinco Hospital grade wall plug. I grounded the shield at the wall plug end.

I was listening last night and it's driving me mad!

How to fix? New power cable? w/RFI canceling? Will it REALLY make a diference? Will 'power conditioning' help? Like an 'on-line' UPS?

Much thanks in advance for you thoughts.
keithcady
marakanetz's avatar
marakanetz
5,473 posts
 
Ha! now I'm catching on...
No one mention about input small signal tubes(or a poorly designed input circuitry). I'm not sure what input tubes are there in Jolida but I think that 80% of your problem are either inside or outside the input tubes + you've probably got a sensitive amp. I believe that further follow-ups can advise you which tubes you should try. IMHO the circuitry have to have a free of microphonics designe no-matter what tubes you're using.
seandtaylor99
1,262 posts
 
Sound not being affected by the volume control just means RFI somewhere after the volume control, which could be in the power amp (that section of your integrated amp) or in the speaker cable. I think it's more likely in the amp, since speaker signals are generally too big (in voltage and current) to suffer from RF interference.
Since one speaker is worse than another to me this points the finger at the amp and not the power supply (the mains).
keithcady OP
17 posts
 
This is making more sense to me as well.

I just replaced all of my pre-amp tubes and the situation seems to be worse. I got rid of the 'junk' Chinese tubes that everyone says I should throw away and replece them with military grade Mullards and Phillips. I'll go back and change them again. Is a copper cage the answer?

I designed a recording studio once in Brooklyn (as and Architect not a sound engineer). due to proximity to the World Trade Center and the Radio Frequencies emmitted therefrom we shielded the whole studio with coper paint and put a copper mesh grid in the air space of the double pane windows.

Thanks Marakanetz, Sean and Seandtaylor99 for saving me the cost of more power cables for nothing.
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