Bus Switches

This kind of switch requires an external power supply. It will automatically switch to the active input and will often include all kinds of smart switching capabilities. In use, this kind of switch is much more reliable than the pasive auto switches, but can still cause problems with games consoles. The Bluedelta Smart-SCART shown in the picture is one of the most highly rated auto SCART switches available, but still has compatibility problems with certain games consoles, especially if you are using an XRGB3 too. If your SCART cables are correctly wired, however, the better auto switches should work in most cases.

One of the most common problems encountered with SCART cables is humming in the audio, especially when the screen is particularly bright. As you might expect, this is caused by interference between the video and audio lines. One way to avoid this is to route the audio cable separately from the video cables and then join them again at the SCART end. Buying higher quality SCART cables with better shielding can also eliminate this problem, though for retro-consoles you’re usually limited to what’s available on E-bay and from specialist video-game stores, unless you can find the components to build your own cable.

https://www.videogameperfection.com/2011/10/28/scart/  for the above quotes.

This kind of switch requires an external power supply. It will automatically switch to the active input and will often include all kinds of smart switching capabilities. In use, this kind of switch is much more reliable than the pasive auto switches, but can still cause problems with games consoles. The Bluedelta Smart-SCART shown in the picture is one of the most highly rated auto SCART switches available, but still has compatibility problems with certain games consoles, especially if you are using an XRGB3 too. If your SCART cables are correctly wired, however, the better auto switches should work in most cases.

One of the most common problems encountered with SCART cables is humming in the audio, especially when the screen is particularly bright. As you might expect, this is caused by interference between the video and audio lines. One way to avoid this is to route the audio cable separately from the video cables and then join them again at the SCART end. Buying higher quality SCART cables with better shielding can also eliminate this problem, though for retro-consoles you’re usually limited to what’s available on E-bay and from specialist video-game stores, unless you can find the components to build your own cable.

https://www.videogameperfection.com/2011/10/28/scart/  for the above quotes.