Ground: needed for some cartridges and not others?

ET16

Well-Known Member
I've been going back and forth between Shure and Signet cartridges on my Mitsubishi DP-EC10. The Shure hums without a ground and the Signet hums with. I don't know what's going on.
 
You turntable ground wire is only used when needed like your finding out. Sometimes it's better with or without.
 
It usually has something to do with whether the cartridge has a ground strap on it, and if the headshell is metal. I find that my stuff hums with the strap in place if the table is grounded. See if either of your carts have a brass bit going from one of the pins to the body. A lot of Shure carts did, but it was removable.
 
ET16: Most typically the generator shell of MM and MI carts will be connected to one of the signal ground minus pins (or actually minus pins, as in fact the minus poles only turn into signal grounds in combination with unbalanced phono inputs...). Usually no problem, if the carts sports a plastic mounting frame, that allows for isolated mounting, so that there's no double grounding/ground loop (one path via signal ground, the other via headshell ground, which usually is connected to the separate ground lead together with tonearm and chassis ground...). Sometimes, however, it can happen, that there's douple grounding despite a non-conductive mounting frame - namely, if the screw heads or the nuts happen to touch the generator shell and that doesn't sport a non-conductive laquer layer.

Greetings from Munich!

Manfred / lini
 
ET16: Most typically the generator shell of MM and MI carts will be connected to one of the signal ground minus pins (or actually minus pins, as in fact the minus poles only turn into signal grounds in combination with unbalanced phono inputs...). Usually no problem, if the carts sports a plastic mounting frame, that allows for isolated mounting, so that there's no double grounding/ground loop (one path via signal ground, the other via headshell ground, which usually is connected to the separate ground lead together with tonearm and chassis ground...). Sometimes, however, it can happen, that there's douple grounding despite a non-conductive mounting frame - namely, if the screw heads or the nuts happen to touch the generator shell and that doesn't sport a non-conductive laquer layer.

Greetings from Munich!

Manfred / lini

Thanks for the explanation and the greetings. I was in Munich last year and loved it. I used to visit in the mid-80's, but I hadn't been there in a long time.
 
Back
Top Bottom