A house doesn't have to be that ancient to have grounding issues. An alert from my power conditioner alerted me to a grounding issue (builder had miswired an entire circuit from the box). Radio Shack has a cheap circuit tester that's well worth the investment. It's critically important. Without a connection to ground, there's a risk that a short won't draw enough current to blow a circuit breaker...bad news for anything on that circuit. Also, many surge supressors and power conditioners *will not work* unless properly grounded. You'll also find that the equipment warranties will mysteriously disappear if you've got a wiring fault.

That said, I don't run any of my systems without power conditioning. You can get a relatively cheap kit at diycable.com (or a list of parts that will let you build one even cheaper). Short story: they work, but you need to be able to separate the good ones from the crap.

BTW, I do own interconnects that retail at $1400/meter, and power cords that retail at $1500 (OK, so I got a good deal). They work too. An upgraded power cord in particular is critical for the 950. It doesn't have to be an expensive one (the one I use for the 950 cost me $50) but the right cord can greatly enhance the musical ability of the unit.