Surge protectors and power conditioners require a solid earth ground. Old houses with two wire circuitry will provide nasty power for good equipment. A 20 amp home run to the box with a three wire full earth ground will make all the difference. The surge protector will now work as intended. A power conditioner is an option to help raise the voltage to a consistent 120v, provide surge protection and reduce noise all in one. The 20 amp power line is still required.
I just went through this for my system and house with a Furman P2400-20, there was a dramatic improvement with a lower noise floor, blacker blacks and much punchier drums. Better current and voltage makes the difference.
I've always used Shunyata 20 amp power cords because I have current hungry tube gear and I trust their ability to deliver on demand. I can't say that about the light gauge power cables from the manufacturers.