@Damiga
Not tried the A520 hack but are you sure you are matching a PAL A520 to a PAL Amiga?
You also mentioned a SCART to YUV converter that had some Ghosting issues. The Amigas CSYNC signal is not compatible with modern video devices un-modified. You need to attentuate the output using a 330 ohm resistor. My SCART cable diagram is shown here:
http://eab.abime.net/showthread.php?t=47281What Amiga do you have?
There are easily made hacks to add S-Video to the A600/A1200 or you can purchase an RGB to S-Video adaptor from Amigamaniac.com, though this is not as fun as hacking something together yourself

Ian