I have a DC switch that is being used as the main power switch for an audio amplifier project I am working on. The schematic is shown below. (a few things are wrong with that circuit, but have since been fixed.) Anyway, I am assuming that, since this is an amplifier, I have mainly a capacitive load? What is the best method I can employ to "protect" the switch from the effects of arcing and pitting on the contacts?
You can move the input filter capacitor to the other side of the switch (leave it connected to the input power) and add a small capacitor (maybe 100nF) on the actual input of the regulator.
You might want to add a fuse to the input (either a polyswitch resettable fuse or a one-time fuse).
An amplifier I took apart for repair had its power switch on the AC side, operated remotely inside the case by a long arm from the front panel button.
If you get the slightly more expensive sort of LDO which has an enable pin, you can use that to turn the regulators on and off. Then your power switch doesn't have to carry any significant current.
Mind you, I wouldn't expect much arcing if you're within the rating of the switch! It's only 1A, and unless you're turning it off at full output volume it won't have that much through it at power-off.