Where is this TT hum coming from? (details inside)

Hello,

I bought a Debut Carbon DC a few weeks ago and I've been battling this annoying hum that seems to be coming from the tonearm/cartridge.
Here is what I know so far:

-It's not the phono stage of my amp - I swapped in my old technics turntable and the amp was SILENT. No hum whatsoever.
-The ground wire from my TT to my amp is securely connected - without it, the hum is MUCH louder.
-The hum gets louder when my cartridge gets closer to the platter.
-When I, with my fingers, touch the little screw that is on the underside of the tonearm (that the 4 cartridge cables are close to) and the spindle in the center of the platter, the hum goes away.
-I've removed and reconnected all 4 cartridge cables just because.

Here is something very strange (to me, at least):
-I took the TT into my local audio store where I bought it because I wanted to get my issue looked at. I brought my own RCA cables and they plugged my TT into an identical amp (to mine at home), and lo and behold, it was SILENT. I felt crazy.

So, must it be something in my house? If so, why did my old technics make NO noise whatsoever when I plugged it in?

I'm at my wit's end, I have no idea what to do at this point.

Thanks for any advice.

 

bumping. still have no idea.

 

Weird. It's clearly a grounding issue of some sort. If the turntable itself isn't earthed, then it's relying on the amp having a good ground connection. It may be that your amp doesn't have a good ground connection - two-pin mains, perhaps? - while the one in the shop had a good ground connection. One experiment to try, if you haven't already, is to get a piece of cable and attach one end to a really good ground like a water pipe. Then take the other end and try connecting it to different parts of the turntable and amplifier - staying well away from the live parts, obviously - to see what effect it has.

 

Do you have anything like an amp very close to your turntable??

 

I had a hum in my system. Turned out it was the Dish satellite receiver nearby causing it. Plugged into the same electric circuit. Moved it and the hum cleared up.