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My ne DAC is a radio tuner inits spare time

310 Views 4 Replies 4 Participants Last post by  Oscar Neundorfer
I bought a musical fidelity x-dac yesterday wich i'm very happy with, however i came across an interesting phenomenon. When the DAC is turned on but has no input (cd-player is off or no digital interconnect attached) al of the lights on the front start to very faintly flicker. When i turn the volume on my amp all the way up, i start to hear soft beeps and other weird sounds. Now comes the really weird part, when i attach a digital interconnect to the dac and hold the other end between my fingers, these weird beeping noises change into intellegble radio sound, i can actually hear what's being said on the radio.

I bought a DAC and got a tuner for free http://www.avsforum.com/ubb/smile.gif

now my question :

Is this "normal" ??

If not is it a bad thing?
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I think to answer if this is good or bad depends on if this happens during normal playback. If you have all internconnects attatched, and you're picking up RF, then obviously this is bad. I would guess a good place to start is to use better shielded cabling/interconnects. If it's the DAC that is picking up the RF directly, you may have to find a tweak that can better help in sheilding. It could be that moving a DAC to a different location may even help. Worst case, would be to replcae the DAC with one that has better internal sheilding.

I used to have neibors that had an illegal,high-powered CB base unit in their house.My stereo didn't even have to be turned on to recieve them! The speaker wires acted as antenaes and the sound came thru very clearly on my Advent Speakers!I knew who was in the hospital,who was coming over and alot of other private information about them that would not be polite to repeat in this forum.After about a month of this, I called the F.C.C. on them and they were shut down or reduced to legal power.Is your sound a broadcast station or CB or Ham radio? Do you know? I'd change the rack position of the DAC and see if it improves or worsens the problem for a starter.I'd hold off calling the F.C.C. until I had some idea what it was.If it's a broadcast station you may be out of luck....


Ms. Bitchlist
The problem doesn't exist when the dac is connected to a "live" source, so if my cd player is on and the dac is connected there's no problem at all.

I think it's regular broadcast radio i'm hearing, last night i listened to about 2 songs, but when they still didn't tell wich station they were i got bored. My theory is that because it's such a simple dac with no form of switching at all it just presumes something's coming in all the time. Even no cables attached gives the interference, just the plug is antenna enough for some of the interference i'm getting. But then again it does'nt happen during normal playback so i'm not to concerned.

Calling the FCC ? I wonder if they are willing to come all the way across the atlantic to shut down a pirate radio station in the Netherlands http://www.avsforum.com/ubb/wink.gif
Hi Frank,

Any audio device with an open input (with nothing except maybe a cable attached) is potentially susceptible to interference from many sources including RF from radio and tv stations. This is particularly true if you are close to the transmitting antenna. I remember an amplifier brand from the 70's that would sometimes self destruct if an input was touched with a finger if you were anywhere near an RF source.

Sometimes grounding the metal case of the product to a GOOD earth ground will help. Sometimes it will make it worse.

Sometimes changing a product's location even a little bit will help.

Generally speaking, if the product under normal use has no problems, then I would not worry about it.


Oscar Neundorfer

Chief Engineer

SMART Devices, Inc.

[email protected]
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