More Grounding Questions

I definitely would not connect the AC ground to the Chassis. The designer would have done so if he wanted, and may have in fact. I would only plug the component into AC as directed.
Likewise, I would not connect the signal ground to chassis, again, the designer would have done so if he wanted.
You may be confusing ground loops with Ground Loop Potentials, which cause hum because the interacting components do not share the same power ground.
If you have no hum, relax and enjoy the music. Please check your previous post, I added a section on controlling surges and line noise.

Vett93
This new post of yours has a lot more going on than the original (ground rod placement and ways to minimize noise). And by the way, everything I suggested was from personal practice after consulting EEs and Union Electricians. Being a retail pharmacist has it's advantages, I get to know a lot of knowledgeable people and pick their brains.

Why do you think your secondary power amp hummed when the signal ground was isolated from the chassis?
If I'm reading you correctly, the chassis of your secondary power amp was internally connected to the input signal ground as well as the power ground. When you isolated the input signal ground from chassis (and AC ground), the hum disappeared. How did you do this? If I read you literally, you were able to do this while leaving the AC ground still connected to chassis. I have seen equipment with "ground lifting" switches, but never used one in practice, nor do I fully understand it. Perhaps another reader can explain further.
Have you been able to obtain schematics of your equipment?
Did you open it up to verify that the power was proper polarity with regard to hot and neutral? Have you checked for leakage?
What equipment do you have exactly? Perhaps other readers have had personal experience. I read a post a few weeks back regarding a preamp/poweramp mismatch. Without getting specific, the two were literally oil and water, one passing DC to another unable to handle it. Perhaps your situation is basic design incompatibility.
I'm no EE but I have built a few kits, fixed a few rigs, and can read schematics well enough to trace a circuit.
Please provide more specific information, I'm intrigued.

Hey Al,
Very nice Jensen paper. I gave it to my son who is studying to be an EE. Even though the paper starts out a little technical, the conclusions and tips section at the end make recommendations to minimize ground loops pertinent to this thread.
Vet93- From a purely academic standpoint, that's a good question, "has the signal been degraded even if you can't hear it?" Unless you can get your equipment into a lab, you'll probably never know. Your ears are the ultimate instrument, maybe you should invest in The Isobar.