I have a mains relay switch (Packard C230B 2 Pole 30 Amp Contactor 120 Volt Coil) which allows me to turn on my pre-amp based on the existence of AC voltage on the amplifiers AC output plug (which is not sufficiently rated to drive the pre-amp). It's been working fine for quite a while, but generates a noticeable "PLONK" sound when switched off, which I know is because of the lack of flyback suppression on the circuit. I want to eliminate this and bought a RIFA PMR205 RC snubbing unit a while ago. Before I install this across the relay, I'd like to confirm that this is the right way to go about this (and yes, I should have never put the relay in without something like this in the first place, but I didn't know better at the time and it worked).
After reading up on this, places like edaboard confirmed that the snubber I have is correct and should be placed across the coil leads (so the connection controlling the functioning of the coil, not the power leads driving the pre-amp and other equipment). I have soldered my RC snubber on the lead wires and will report back on any issues once it has been operating for a while.