The "click" in good high-power hifi could just as likely be protection to prevent the output stages blowing at switch on, especially if the speakers aren't connected!
You could always count on most Amstrad "hifis" (now there is a contradiction in terms) blowing the output amp IC by just switching them on with no speakers plugged in - even at their "wapping" 20 watts PMPO (not even REAL watts) and the volume turned all the way down.
The main thing with equipment like a second processor PSU using a toroidal is that the mains fuse will probably be a time-lag/anti-surge/slo-blow type. The "in-rush" being the big gulp of current the transformer takes from the mains at switch on. A common mistake is replacing the fuse with a higher (standard type) rating because it keeps blowing at switch on.
You get the same effect if using toroidal 12V halogen lighting transformers. You can often find you need to swap the MCB on the lighting circuit (normally type B) for a type C of the same rating to prevent "nuisance" tripping.
EDIT: That reminds me! See new topic on current curve tracing....