@CobaltVelvet apropos ebay; saw this yesterday : https://www.ebay.de/itm/7-5m-750cm-Y-Adapter-Cinchkabel-Premium-2-Kanal-auf-4-Kanal-294-m/401058311352?hash=item5d60f02cb8:g:MS0AAOxylpNTVjIP

bargain rca cable - only 300 EUR per metre ;)