Vast Soind Effects Library

Very cool, and it has some kind of mixer control and a video of some attractive girl showing you how to use it, but when I click the video it says the video is "not available in your area". 

Its archive looks well categorized, I haven't dug in yet but theres bound to be some useful sound-toys in there.

https://sound-effects.bbcrewind.co.uk/

Probably requires you to be in the UK.  The BBC has a vast audio & video library from radio & TV shows, but only available to UK residents.  The way to get around that is to use a premium VPN that truly is anonymous and uses a UK IP.  Some VPN's just don't work - Windscribe (and there are lots of others, I just happen to use that one) does.