Is there any benefit to be gained from placing a K4700 between valve [tube] amplifiers (in my case, refurbished Quad II, which have a pair of 6L6s driving an output transformer) and speakers? Switch-on thump is hardly a problem, as the valves take tens of seconds to warm up. And it’s hard to see how DC is going to get into the secondary of the output transformer.
I am nervous of connecting expensive speakers to elderly equipment, so looking for all the protection I can get!