Korn: Don´t skip the separate grounding!! Not the ideal setup as has been described. Definitely you´ll get improvement over where you are now.
The use of copper grounding rods only for your system mentioned in the above notes. I haven´t go that far to three separate and so forth but use two it´s worth the effort. What I actually did is I´m feeding my system out of the 220 volts electric range breaker (I use a gas one now) so it was a freebie (nice isn´t it)taking two 110 volts one for the amp and another for front end using dedicated grounding rods. Regards
I´ve found an improvement over bare wire connection (connecting the lines to breakers and main blade switches using cable terminals.(tin plated for less maintenance or pure copper that will require corrosion cleaning). You can use larger than nominal cable awg terminal and make a small loop of the stripped cable, put it inside the terminal and solder it very well. You have this way far more contact area and solder all over the cable surface. I used lead free solder with silver content. The flat surface of the cable terminal providesa very good contact with the bolt and flat metal underneath it. Or simpler maximize the bare wire contact by using the loop trick. Picky I know but it´s been good for me.