First, anything less than a whole home surge protector is a waste of your time and money. They aren't that expensive. But remember the only way to avoid damage to any electrical device from a direct lightning strike is to have them physically unplugged from the wall socket.
Second, there is no power conditioner or surge protection that will improve sound. That is not a thing that exists in the world of physics and the science of sound. So don't be fooled by those who say otherwise. The truth will set you free (and protect your wallet).