SCARTMUX - Automatic RGB SCART Switch


Automatically switches to to the active input, determined by monitoring the sync/composite signal. There are two outputs which are both active simultaneously.

The unit requires power to operate. This is supplied via the USB-Mini socket next to the output connections. A USB phone charger with an appropriate cable is suitable to use as a power supply.

Input: 4 x RGB SCART (does not support s-video, component video).

Output: 2 x Mini-DIN 8 pin (Framemeister pinout) RGB + 3.5mm stereo audio. The audio signal is output from the mini-DIN connector if there is no cable plugged into the audio jack.

Size 142.5 x 82.5 x 25.5 mm, weight 180g

Setting Up

There is a bank of four small configuration switches is located inside the unit. To access, use a Philips head screwdriver to remove the four screws keeping the shell attached. Use a tiny screwdriver, tweezers, or other pointy tool to change the switch positions.

The switches are labelled from 1 to 4.
Switch nr. Description Default position
1 Output 1, switching signal (+5V from mini-DIN pin 5) Off
2 Output 2, switching signal (+5V from mini-DIN pin 5) On
3 Rank priority mode Off
4 Sync Separator Off

The switches number 1 and 2 control the presence of the switching signal on their respective mini-DIN output connection. When connecting the SCARTMUX directly to the Micomsoft Framemeister scaler directly with a mini-DIN straight through cable it's better to turn this signal off as it's not designed for such a signal to be connected to this pin. If you are connecting the SCARTMUX to a CRT television set via a mini-DIN to SCART cable you will need the switching signal turned on. If you are connecting the the unit to another scaler, such as the OSSC or something else that does not require SCART status signals then the switching signal is irrelevant.

By default the SCARTMUX will switch to the first input with an active sync/video signal. It will not switch to another input until the first signal has stopped. If rank priority mode is turned on, inputs are ranked in order with input 1 having the highest priority and input 4 having the lowest. A higher ranking input could interrupt a lower one, but not the other way around.

Pin Listing

SCART Inputs 1,2,3,4

Pin Description
1 -
2 Audio right input
3 -
4 Ground
5 Ground
6 Audio left input
7 Blue video input
8 -
9 Ground
10 -
11 Green video input
12 -
13 Ground
14 -
15 Red video input
16 -
17 Ground
18 Ground
19 -
20 Composite video/sync input
21 Ground

Mini Din 8 pin RGB outputs 1, 2

Pin Description
1 Audio right output*
2 Audio left output*
3 Composite video/sync† output
4 Ground
5 Switching signal‡
6 Blue video output
7 Green video output
8 Red video output
Shield Ground

*The left and right audio outputs on the mini-DIN connector are disconnected when a jack is inserted into the adjacent 3.5mm audio output socket.

†If the sync separator is switched on the output is 75 ohm sync, otherwise it drives whatever signal is present on SCART pin 20.

‡If there is an active input the output the switching signal is a 5V output, capable of sourcing 200mA of current. When there is no active input the output is 0V. This signal can be disabled via the configuration switch.

Change Log
18/6/2020 - Page created.