fixing hum on Rega Rp6


Hi all-
LIke some other Rega owners, I experience a moderate hum that seems to have something to do with lack of grounding from the power supply.  I went ahead and ordered an upgraded power supply from Swagman Labs, which should take care of the hum and have other sonic benefits.
http://www.swagmanlab.com/Product_PSU?product_id=664

It will be a few weeks before that arrives.  In the immediate, I found this fix for running a ground wire from the existing Rega PSU TT.
http://www.audioappraisal.com/tip-ground-your-rega-ttpsu-to-reduce-hum/
I haven't done this yet, but my dad (an engineer!) is very excited to try this experiment over Christmas.  So my question is once I have the Swagman unit do I need to unhook this grounding wire, or is it likely to add value even with the Swagman?
Finally, will an upgraded power cord with the Swagman also be a worthwhile investment?
Thanks and happy holidays!
Margot
mcanaday
Hum is caused by a voltage-potential difference between two components. Connecting them together by a piece of wire fixes this and eliminates hum.
Post removed 
My RP6 had some hum at times. I tried running a ground from the TTPSU to the phono preamp. Later diagnosis lead to a bad tonearm cable that was replaced under warranty. Now it is quiet to 50% volume (which is very loud on my system) with very little hum / hiss using a low .3v MV cartridge. If you unplug the TTPSU from the table, do you still get hum? If so, giggle the loop of the tone arm cable just after it comes out of the arm. 
Thanks very much!  I hadn't thought of the tonearm.  I will experiment with this and see.

The problem is intermittent, but I haven only noticed it when the TTPSU is plugged in...

Margot
Post removed