@whale-av Thanks for your tips. I use Linux and via the link you posted I can install Pd-extended for very, very old versions of Linux Mint (which is the distro that I use). And I want to use Pd on my Raspberry Pi too, so I'd rather be "future-proof" and try to get it working in Pd Vannilla w/ some externals.
Problem is that I do not know what externals this patch uses. So I do not know what to download in Pd via the menu: "Help --> Find externals". I've tried to install some externals, but you must not search the name of the "object" but the name of its developer!
Example: say you want the Filter "lowpass 22.214.171.124.order with freq and Q signal inlets" made by iemlib (see this link). Then in the 'Find Externals' window you must type in iemlib. Not filter or lowpass.
Another problem is that I might not be using this patch right. I load it in Pd, activate an oscillator by placing a cross next to "on" and raise the volome of the osc and the master volume. I connect a Midi keyboard to my PC, connect it to Pd via qjackctl and play some notes. Nothing happens and I do not see any errors in Pd's console...