are some phono stages more resistant to hum?

One of my phono stages is the same ARC PH-3SE as you have. I have used this with at least a dozen different tables and arms and have never had a hum problem.

You are absolutely right that a "shielded" cable/wire should have a much better resistance to RFI/EMF/hum.

I think something is amiss with your setup. Who did the rewire and what kind of wire did they use?

Did you have the hum before the rewire? If not, it has to be in the rewire somewhere.

You also may have wired your cartridge incorrectly. If your wire joins the shield and the "negative" lead then you could get hum (I don't know the specifics of your wiring harness).

But make sure you've plugged in the right color wire to the right cartridge pin. One way to be sure is to use an ohm meter with the phono cable unplugged. Then check ohms between the blue wire and the shield for the RCA jack of the left channel. Ohms should be very low 0.3 or something like this. Then do the same for green and the right shield for the RCA jack. Now do the same for the right channel RCA jack tip and the red wire (0.3 ohm or less) and the white wire and the tip of the left RCA jack.

Now check a metal part of your tonearm (between the headshell and the bearing in case your bearing has a plastic cup) and see if it has a low ohm reading to your ground wire.

Noisy tube in the AR unit?

thank you, will try all these things. I did try different tubes, not the problem.

when I do not connect the ground wire from the tt, just leave it dangling unconnected to anything, the hum is greatly reduced. What does this imply? problem with the way the entire system is grounded? I live in an apartment, and have no control over the non-audiophile wiring setup.