Can't tell,if my house is properly grounded


Hey guys, I have a low level hi/low buzz that is coming through my speakers, not dependent on the integrated tube amps volume. It is amplified when I turn on my Parasound JC3+ Phono preamp, but only slightly. I have the power cords going to the same outlet. I tried running their power through my Furman Elite Power conditioner but that changed nothing. I ran an independent ground wire and checked all the components in various configurations to no avail. I disconnected all the tv cable to make sure it wasn't coming from there and that solved nothing either. I turned off everything in the house I could' no change. I checked my ground outside at the rod and it is all solidly connected, however the depth of the rod is unknown.

any other thoughts before I call out an electrician?
last_lemming
The house is 15 years old. So new buy code standards. The room is a small bedroom. 
OP, I realize you already have a Furman Elite Power conditioner, but to the point of the thread (based on the topic title), there are plenty of electrical testing devices to check for proper grounding. 

Something simple like an Emotiva CMX-2 which can remove DC (not saying that is the cause of your hi/low buzz) also has line monitor LED indicators that detect "line correct", "open ground", "open neutral hot ground reversed", "open hot" and "hot neutral reversed". 
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Will do - just so I'm clear:

hot = smaller blade
neutral = larger blade
ground = small round hole below the two blade holes. 

I know I sound like a simpleton here, but I don't want to shock myself or damage the equipment. Also I'm assuming I will not damage the equipment as long as I follow the above procedure - for instance testing hot and neutral at the same time while equipment is on. 
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