[rodge827]

Ok,

So I come into my listening room tonight and I have a faint but audible radio program coming through my speakers. Funny thing is I don't have a tuner!, and this is the first time this has occurred. My system is all digital and I leave it on 24/7 to keep the chips warm and toasty. I did a little trouble shooting and the radio signal is getting picked up before the amp, so I'm guessing the speaker cables aren't the culprit.

System: Transport - Empirical Synchro Mesh - Dspeaker Dual Core - iFi ITube - Crown XLS1500 amp

Gain on amp is turned up high to match the gain on the sub amps.

All cables are DNM HFTN (unshielded) Dig cables are Coax shielded and Optical to the Dual Core.

How can I fix this issue?

Chris

[Folsom]

Do you have a dedicated line to the room, including safety ground? That helps. If not the changing potentials in series can make RF and friends come and go.

I've found other bizare things like the orientation of extrusion of aluminium heatsinks to play a role.

[rodge827]

No dedicated line as of yet and what is a safety ground?

[G Georgopoulos]

rf can only picked up by amps,rf is weak it needs amplification,check your amps small signal or large signal check input wiring, check modifications you did and caused this...

[Folsom]

No dedicated line as of yet and what is a safety ground?

You may refer to it as "earth ground", but it's safety until it hits the breaker. It's the 3rd prong on power receptacles and plugs

[rodge827]

check modifications you did and caused this...

No mods on the amp yet only stock.

You may refer to it as "earth ground", but it's safety until it hits the breaker. It's the 3rd prong on power receptacles and plugs

Thought that was it.

[jk@home]

I have an old MF X-10 tube buffer that did the same thing when I stuck it in the HT system. Don't know if it was the buffer or the cables, but that was the only place in the house that it occurred.

It looks like your un-shielded cables are designed to block RF?, But can you get a hold of and try balanced cables from the Dual Core straight into the Crown? Using Mogami 2534s here.

Did you have to put extensions on the Crown power cords (I know they are short)?

I sometimes wonder if a lot of the talk of class D needing tubes to warm them up is really RF present or getting into the lines.

[rodge827]

Yeah I thought the iTube could have had something to do with it.
I will try the Mogami Cables.

[rollo]

   Roger is it still present today ? A recent occurrence correct ? Did you change anything at all ?


charles

[jk@home]

Yeah I thought the iTube could have had something to do with it.
I will try the Mogami Cables.

You can order bulk cable and diy on connectors, or go to a place like the Guitar Center and go turn key by buying the Mogami Gold Neglex Quad Microphone Cable (and maybe be able to take them back if not needed?):

I had extra Neutrik connectors on hand, so just bought a single 15' length and made two cables out of that.

[dB Cooper]

All cables are DNM HFTN (unshielded) Dig cables are Coax shielded and Optical to the Dual Core.

How can I fix this issue?

Chris

Well, I believe there's your problem. Not sure why it just arose though.

[bladesmith]

If you haven't changed anything in your setup/system, then how do you know its not an issue with the local radio station over-modulating ?

[rodge827]

   Roger is it still present today ? A recent occurrence correct ? Did you change anything at all ?

charles

Charles, it isn't happening now, and yes this is a recent occurrence, and yes I made a couple of changes. Last week I purchased another DNM HFTN IC cable, but it replaced a standard DNM IC. The amp is new and has been in the system for about 2 weeks.  Other than that every thing else is the same.

Well, I believe there's your problem. Not sure why it just arose though.

Was thinking that too, but don't want to go to shielded cables. I really like the DNM HFTN IC's.

If you haven't changed anything in your setup/system, then how do you know its not an issue with the local radio station over-modulating ?

Possibly. The station is relatively local and has many transponders around the area, kinda like NPR.



Thanks for the interest gents, after I was done listening around 1:30am there wasn't any radio signal present. But who knows what might happen later on...

It freaked me out a little. 

I went into the room, closed the door, and heard this talking. What the? So I put my ear to the driver and...

Chris

[Wayner]

Ok,

So I come into my listening room tonight and I have a faint but audible radio program coming through my speakers. Funny thing is I don't have a tuner!, and this is the first time this has occurred. My system is all digital and I leave it on 24/7 to keep the chips warm and toasty. I did a little trouble shooting and the radio signal is getting picked up before the amp, so I'm guessing the speaker cables aren't the culprit.

System: Transport - Empirical Synchro Mesh - Dspeaker Dual Core - iFi ITube - Crown XLS1500 amp

Gain on amp is turned up high to match the gain on the sub amps.

All cables are DNM HFTN (unshielded) Dig cables are Coax shielded and Optical to the Dual Core.

How can I fix this issue?

Chris

There is your problem. Unshielded interconnects can act like antenna.

[DaveC113]

If the unshielded ICs haven't caused it before not sure why they would start now.

I have had this happen once, a couple years ago. I walked into the room and a radio station was playing at low volumes... I have no tuner either! I turned my system off and on again, it disappeared never to return. 

[rodge827]

Thanks Wayner was thinking the same thing.

If it happens again could I wrap something around my existing cables?  Suggestions?

[DaveC113]

Yeah, you could try wrapping the ICs in aluminum foil and touching one end of the foil to the ground connection on the IC cable.

[rodge827]

If the unshielded ICs haven't caused it before not sure why they would start now.

I have had this happen once, a couple years ago. I walked into the room and a radio station was playing at low volumes... I have no tuner either! I turned my system off and on again, it disappeared never to return. 

Thanks Dave, will try that too if it happens again.

I have heard of this happening to other guys, but this is my first experience with it. I was listening to "International Guitar Night II" and during some of the very soft passages there were two guys having a conversation and it wasn't crowd noise...weirdest thing...

Chris

Yeah, you could try wrapping the ICs in aluminum foil and touching one end of the foil to the ground connection on the IC cable.

Thanks Dave, will try this.

[stereocilia]

I had this with a tube amp. Shielded interconnects were no help. I didn't get to trying shielded speaker cables before selling it. My guess is that the tube is the issue. It's a frustrating problem; good luck.

[avahifi]

If your speaker wires are conventional two conductor side by side construction, I suggest you try twisting them 3 turns per foot.  You can do this easily by chucking them into an electric drill.

Speaker wires can pick up radio stations and twisting them provides a reasonable measure of self shielding.

Frank Van Alstine