Advice on RFI with a new integrated amp


I need some assistance on my Exposure 2010S. The only input I am using is the cd player, but with volume turned all the way down, I am picking up radio signals. If I turn the dial to the moving coil phono setting, even though nothing is attached to it, I can hear radio pretty loudly.

The corner of the house where our stereo is in under the outside wires, and it sits right next to the terminal for our Verizon Fios -- not the most ideal location, but it
is the only option.

Using the CD pots on the amplifier, you can only hear the radio pretty faintly, when the volume pot is turned all the way down. If I am playing cds, you can't hear anything, but since when I switch to the phono/aux1 setting, as I mentioned, I am picking up radio signals, and
the volume is louder. From what I read (and hear), it appears that the phono pot (perhaps in cahoots with the moving coil phono stage) is acting as a antenna, and picking up signals, which are cross-talking
across the other inputs on the amp.

How would you recommend addressing this? I am currently considering
shorting terminators on the phono, and other output pots and found some terminators online (audiophilia article).

At first I thought it might be my changing the speaker cables, from very thick cables to the slimmer DMNs, but that would not explain why the RFI is louder at the phono input than any of the others.

Whatcha think? Does this make sense?

The other option would be RCA caps.

Thanks,

Marty
martyw

Showing 15 responses by martyw

Thanks -- to be honest, I am ready to sell it and move on. Not to mention, I really miss the warmth of my old tube amp, so I am going to try and find something that gets me closer to that.
Thanks Jea,

On point one, sorry -- I meant inputs.

On point two, yes, the volume increases if I turn up the volume, but again, it is most prevalent on the phono setting. On the other settings, it is there, but very much in the background.

On point three, the old cables are gone -- they were spades, and not compatible with the new amp, so I sold them.
Thanks again -- Marty
Hi Al,

Thanks for the tips. I ordered the shorting plugs, and they should arrive later this week.

I do get radio when there is nothing connected to the inputs. I played around with putting a ferrite bead (from an old USB plug) by the phono input, but it made no difference.

When I am using the other pots, you can only hear the radio, when your ear is very close to the speaker, but it is pretty annoying nonetheless....

Thanks,

Marty
Hi all,

So the shorting caps didn't address the RFI, even when in the phono stage. Would the next step be swapping out the moving coil stage and putting back in the other piece (I am not sure what its is called -- I think internal jumper? If so, who can do that?

Thanks -- Marty
Another thought, while I had the shorting plugs in -- I have nothing connected to the "outer ground sleeve" Is that the little metal piece on the back bottom of the amp that says ground?

Thanks -- Marty
Hi Jea48. The radio station is the same. I also swapped out the moving coil phono, and it is still coming through. I'm giving up on this one -- posted it on Audiogon last night for what I paid for it.

Any ideas for well shielded pieces? I am currently looking at Odyssey, either their cyclops integrated, or the khartago power amp paired with the Vincent SA-31. Any thoughts if that would work? Odyssey gear seems pretty well-shielded.

Thanks -- Marty
Hi Al and Jim,

Not sure how far away they are, maybe 1 mile? The signal is FM. Besides the amp, the only thing that changed is the speaker cable (from wireworld biwire to DMN single run). Interconnects and speaker cables are the same.

Figured the easiest thing at this point is to quit while I am ahead, sell it, and find an amp I can demo at home first.

Thanks,
Marty
HI Al,

Couldn't the rca inputs act as an antenna? Or could it be the speaker wire?
I have some zipwire from best buy, but it is unterminated. The exposure only works with bananas. Is there any way to test it with the unterminated wire?

thanks -- Marty
Solved it!!!!!!!!!! It was the solid core cables!!!! I tried some stranded radio shack cable and cheap banana plugs and no more radio coming into the amp. PHEW!! Of course, still going to sell it -- I miss my tubes, but glad to know I am not crazy!

Thank you all for your help!
Thanks Al and Jim -- It was a bit of a wild goose chase, but glad to have figured it out in the end. I probably should I have tried swapping speaker cables in the first place, but I didn't have any to try so I looked for other possible causes -- oh well. At the end of the day, it is just not the right amp for our situation. There are only two Exposures listed for sale here (including mine), so I don't imagine it taking too long to sell.

Thanks again for all of your help -- Marty
Well gentlemen,

Looks like the devil is still hanging around. I am trying out a new amp and new speaker cables (nait 5i and naca) and am still getting some RFI (can only hear it when 6 inches or so from the speaker). Is this normal? Could it be from the power cords? All my cables are bunched together behind our media cabinet as well...

Thanks -- Marty
Hi Al,

Exactly -- high frequency hiss, but with a beat. Since it clearly is not the amp or the interconnects, I will try swapping out the stock power cords.

Thanks again for all of your help!!