Need helps with hums, radio station in phono

08-07-12: Suteetat
Tbromgard, I tried it only with phono cable as I use Stealth Dream AC cord on my phono unit, not sure where I would find ferrite ring that big!.

I hope that you are using a "Preamp" version of the Dream power cord. The Dream was designed so that it provided "star grounding" for a system. Therefore, the "Preamp" version has a clearer path to ground than the "Digital" or "Amp" versions.

Huh? Not buying that one.

Yes I use pre amp version of dream AC power cord on my phono and pre amp. Also the proper version for power, digital and conditioner so I have a variety of multi color garden hose everywhere :)
I don't know if it is the star ground or whatever but when I auditioned Stealth power cord in my system, I tried only one initially and was not overly impressed. It was not bad but not really better than what I had. Only when my local dealer gave me two more AC cords to tried in my system then it really was a different story. So, the more the better it seems with Stealth AC cords.

I did end up trying the method peter lederman suggested. I used some 3-prong to 2-prong adapters from ace hardware. The only component I left earth grounded with the 3-prong power cord was my phono stage. Then my processor,amp, and turntable are connected to the ground lug on the phono stage chassis. This has totally eliminated all hum at my listening chair. The only way I hear a hum is when I turn the volume up to max and I put my ear next to the tweeter or midrange driver. This is more than satisfactory for me. I never listen to music at max volume or sit right next to the speaker anyway. I do listen to music at 85% of max volume sometimes. I can hear no hum at all at these levels. I am going to leave the adapters in place until I can come up with a better solution.
As a precaution, I added some extra shielding to my phono cable and to my tonearm lead wire. I had some scrap monster speaker cable junk laying around. I cut a 12" length off and stripped the shielding from the wire. I then removed a single strand of copper wire about the same diameter of a hair and wrapped this around my tonearm lead wire in a spiral fashion. I left this wire about 3" long and connected the end to the ground lug on my turntable. Once I had this wire installed I wrapped it in PTFE tape. I also wrapped my phono cable in PTFE (teflon) tape. This has also helped to cut down on EFI/RFI interference. It was a tedious process to hand wrap these cables but, the end result was worth it.

Andy

PS
I am using a VPI classic 1 with the exposed wire coming out of the tonearm head. This wire is un-shielded and was picking up interference. That is why I grounded it and added shielding.

Hi Andy, now that you know a way to fix it, the next step is to find a way to correct the grounding problems that cause the need to lift AC grounds from the wall.

For example what happens if the DAC is unplugged from the wall? Ca you ground everything else normally? If not, then the DAC may be off the hook.

FWIW, in the old days grounding the preamp as the heart of the system was considered normal practice. In this day of liabilities, that is no longer considered a good idea.

If you continue to operate things with the grounds lifted, there is a shock and fire hazard if a piece is damaged or has certain types of failures.