According to an old forum thread the Leak 3200 is basically a Rotel RX-402 in Leak clothing. That being so the attached owners manual may be of some help. Note that the Rotel version doesn't use speaker DIN plugs. This eBay seller is offering suitable plugs with screw connections so no soldering required:
https://www.ebay.co.uk/itm/331395432...Bk9SR8CmhOy_YQ
Alan