Tri-Planar grounding question...

The shield does not go through the gimbled bearings. Inside the arm tube, the tube itself is the shield. So the arm ground is usually picked up somewhere near the base, probably very near where the wires transverse the gimbles.

There is a small screw on the base of the arm that goes through a small flat washer which acts to ground the arm and wire shield and also as astrain relief andsecuring screw for the cables leading to the preamp.

Ok. This all makes sense to me now... thanks guys!

WIRES - I see where the screw is and it looks like the washer is in fact attached or soldered to the shielding of the cable.

Is it common practice to attach the ground wire to the tonearm and the shielding together? Wouldn't this create a ground loop? (Just wondering...).

Dogpile, It is my understanding that it is common among shielded interconnects to connect the shield to the negative wire, which can cause a ground loop since the negative wire often does double duty as the ground.

If in the Triplanar, if the shield and the tonearm are connected to the ground wire which is in turn connected to a grounding post that is out of the signal path, then I don't think such an arrangement would contribute to a ground loop and would be superior to affixing the shield to the negative wire in the interconnect.

If the grounding post is connected to the negative wire somewhere in the circuit downstream, then such a configuration could contribute to a ground loop.

I think this is arguably an advantage of xlr interconnects in that the shield is never connected to the negative wire and the ground is altogether out of the circuit.

This is my beginner understanding of grounding topology. Perhaps Ralph or somebody with more grounding understanding will jump in here.
Jeff

Jeff, I think you got it right. The reason it is not a ground loop is that the only place the ground occurs is the shield of the cable. Without that connection to the arm, the arm would be floating and it would buzz like crazy!

This concept is common to nearly all tonearms BTW (including BSRs from the 1960s). Since the arm is a separate ground circuit from the cartridge wiring, it is also why tone arms are or can be a balanced source.