Turntables and Hum

yes it is very true. I don’t use shielded interconnects and I’m not afraid to say it. Has always been part of the plan to acquire some but haven’t pulled the trigger yet. 

I finally got some shielded cables - Lautus and some CuSat50. Interestingly I discovered that the RF noise in my system from the nearby dimmer switches is not entering through any of the components or cables. It’s coming through the turntable. I’ve been reading your posts about improper grounding on modern TTs and I think I’m the owner of such a TT. I believe it’s the TT because when I plugged a digital source into the ULDE the dimmer switch hum went away completely. 

In my experience, the culprit is usually the tone-arm "wand" - the waggly bit with the cartridge on the end - often, the mounting base is fine.

The Technics "wand," for example, has five "cartridge" wires inside. The black wire connects into the headshell adapter fitting, then runs the length of the "wand" along with the four cartridge wires.

All five wires then thread through below the bearing block, down into the arm base. Fitted inside the arm base is a small, simple printed circuit board with lands to which the wires are soldered, and opposite, the shielded cables attach, and the black arm "earth" wire.

As a result, there is electrical continuity all the way. Contrast that with "hi-fi" arms. I don't see many/any with the fifth wire. So how do they ground out the "wand"?

The only possible connection is the mechanical connection, which is the arm bearings (or single bearing on a uni-pivot). But bearings need to be lubricated, or they'll seize! A grease or oil film gets applied at manufacture, and somehow, the circuit ground conducts through that? If it does conduct, it conducts poorly.

But it gets worse. Carbon fibre is now the fashion, but as every car mechanic knows, it's resistive! If something is resistive, it doesn't conduct very well, but to "ground-out," it needs to conduct!

So why would they do this? Sound-effects! The ethereality - the not to be of this world!

Right on the knife-edge between stability and instability lies a "wonderful world" of "projected imagery." As one user was overheard to comment, "you could almost touch the electrons in the air as I was listening last night." That was met with nods and smiles by the (unnamed) company owner.

I have a suggestion: try lysergic acid diethylamide! I am told it is far cheaper than boutique hi-fi and makes any system sound out of this world! Even if you don't have a system!

Even the old BSR  and Garrard consumer turntables had properly grounded arms.