Phono stage picking up radio signals?


The strangest thing happened this evening. I just hooked up my Whest phono stage and as I was letting it warm up I turned up the volume slightly to check the noise level and noticed a strange noise coming from the speakers. At first I thought it was a ground loop hum or some feedback, but when I put my ear to the speaker I distinctly heard music. I turned up the volume a bit and to my surprise I could hear and identify the song playing, followed shortly after by DJ banter. It was obvious I was picking up a radio station, but I don't have a tuner or any other radio device in the home. Can anyone give me a clue as to what might be going on.
clio09
Clio09: Your preamp is OK running thru the RSA if the RSA is grounded. (And I'm assuming your wall receptacle ground is functioning?) Yes, do try removing the ground pin from the PS cord, however that's more for hum prevention, but still a good idea.

The Kuzma should also have a separate ground wire (bundled with the "fixed cable") that you can attach to the ground lug on the back of the Whest, or on the back of the main preamp. Ditto the TT, however, again, these are mainly for hum prevention. I was surprised to learn your Stogi came w/ a dedicated IC, but I've gotta believe it's high quality and shielded. And I don't think the Sota power supply is the problem.

Which brings us back to the IC's I honestly don't know anything about the Nordost Red Dawn cable topology (conductor layout/design) and a number of cable manufacturers make unshielded cables that still have arrows so you can always install them in the same orientation after break-in, so don't assume the Red Dawns are shielded. Check with Nordost.

A quick and dirty diagnostic for the Red Dawns is: while the problem is evident, touch one hand to a bare metal spot (like a screw) on the grounded preamp chassis, and with the other hand, grab both Nordost IC's, and see if the radio reception doesn't diminish. If it does, then they're the problem.

I've never tried a Ground Zero. I've always achieved "star grounding" by making my preamp the only component that was grounded thru its power cord. (Caution: don't work on amps or other components unless the IC's are in place or you've re-grounded them at the wall.) Again, this is a ground loop issue, and if your system has no or very little 60 cycle hum, then you don't have ground loop problems.
Nsgarch,

Thanks for the advice. The TT does not have its own ground cable, but it does have a ground lug under the chassis. I imagine it is for the tonearm cable ground wire. I prefer attaching the ground to the phono stage instead. My preamp is a Cary SLP-98 which is offered as a linestage or with a phono stage. Since I only have the linestage the RCA inputs for the phono section are plugged, as are the tube socket holes on the top of the chassis. However, it also has a ground lug and I wonder if I should try connecting the ground for the tonearm cable there as well. Probably can't hurt.
Those interconnects have to be shielded or else yau can start enjoying radio while you listen to records. BTW any problems with clicks and pops?
Nsgarch,

As for the Nordost cables they are not shielded according to what I found on their website. They have also provided a reason as follows:

"The use of flat cable geometry coupled with very precise conductor spacing alleviates the need for conventional shielding. In addition, the use of extruded Teflon provides better shielding than conventional insulation techniques. Nordost cables are not shielded because shielding increases the capitance of the cable by a factor of 55% or more when applied in the conventional manner. If the capacitance of the cable is increased high frequency information is rolled of and you don't hear all of the musical information."

Not sure if this is a proper explanation or if it is contributing to the problem as you indicate, but the P300 didn't solve anything and now I'm going back to the Cary to compare.

I'll post an update and in the meantime post a thread for suggestions of shielded ICs.
Hooked up the Cary PH-301 which has 3 x 12AU7 and 2 x 12AX7 for tube compliment and while its noisy (hiss and some static) there is no FM or other radio interference that I can tell.

I'm at a loss at this point. More suggestions are welcome if any one can think of anything. Thanks