Does AC line power issues negatively affect Code series amps?

I have some problems with the wiring in my home (USA), one meter that I used indicates grounding issues. 

My home was built in the mid-70s so I suppose that it was built according to the code of that time period. One thing that I've noticed is that there are no grounding rods for the electric box. Current code requires that 2-6' rods be driven in the ground approx 6' apart connected to the power box to provide proper grounding for the electric service and safety for the home

I've said all of that  to ask how extreme noise on AC power lines affects a Marshall Code 50?  I can hear the noise thru my amps. I've tried using a Morley line filter plus a line filter that I built and neither helped.

There are times that my amp sounds like the signal is fluctuating, causing the volume to go high & low. I can't get the tone from that amp that I should be able to. There are other issues as well - I'm not satisfied with the performance of my Code 50 but I don't know that it's the amps fault

Thank You 

Keith Stone

aka GnLguy