Protect or make them sound better?
The best way to protect is to install a whole house surge protector.
Sound? A regenerator. But it depends on the equipment. I've had tube amps sound worse on battery-based power supplies than directly into the wall. But I have clean power. If you do go the regen route, listen with and without before assuming you have to stay with the power supplies and end up spending more trying to get back what you lost and thought you'd gained.
The best way to protect is to install a whole house surge protector.
Sound? A regenerator. But it depends on the equipment. I've had tube amps sound worse on battery-based power supplies than directly into the wall. But I have clean power. If you do go the regen route, listen with and without before assuming you have to stay with the power supplies and end up spending more trying to get back what you lost and thought you'd gained.