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RFI issues in phono stage-one channel only ??

Running BAT VKp10 phono into VK50se pre. The left channel has RFI intermittently. Can get loud enough to interfere with the music, and not just on quiet passages. Sounds like a spanish radio/tv station.

Also, any time the furnace or certain light switches get turned on, I get a pop, rather loud, through the same channel. This does not occur on other sources.

The RFI used to be in both channels, but a new tonearm lead and shorting plugs (for the unused XLR input on phono stage) took care of that.

Could this be a bad tube ? Grounding issues in a cable on one side only? Ideas? Thanks in advance.
128x128jfrech
5 responses Add your response
twl
3,251 posts
 
I'm thinking it would be in one of the cables.
sean
6,231 posts
 
Sounds like a bad cable to me too Twl, but it could be a bad solder joint in one of the components. Sean
>
musicslug
430 posts
 
Is the RFI problem channel (its cable, for example) closer to a window? Is one side's cable looped (acts as an antenna)? Try turning the phono or pre 90 degrees... Stuff like that can impact in-city RFI problems. Where I used to live, there was so much RFI coming in the windows, I had to move the system (minus the speakers) downstairs. Nothing else worked (RFI blockers, cable wraps, etc.)
zaikesman
3,017 posts
 
Does the radio signal get quieter if you cup your hands around the cartridge body? If there is a tuner in your system, does it help to unplug and physically remove it along with its antenna? Is there any change in which channel is affected if you reverse the channels with your phono lead cables?
marakanetz's avatar
marakanetz
5,473 posts
 
try flipping tubes in phono section and see if the channel changes if flipping wires yealds the same result. if rfi changes to a different channel than i guess it's a tube.
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