Sega Blast City - Video Splitter

[UltimateTofu]

I'm trying to duplicate the video signal coming off of my head-2-head Blast City cabs with Nanao MS-2930 chassis using the Sega VS kit, but when I add a splitter or distribution amp in between the brightness gets halved.

I have used a powered VGA splitter or a distribution amplifier to split the signal coming off Player 1 before it reaches Player 2, but the brightness gets halved the moment the source side is plugged into the splitter regardless of it sending signal to any other devices.
These are the devices I've tried for reference:
https://www.tripplite.com/4-port-vga-sv ... f~B114004R
https://www.rdlnet.com/product.php?page=568

I only experience this issue when running arcade PCBs over JAMMA inside of the cabs.
If I send a 480p signal from a PS4 for instance, I can split that on the powered VGA splitter with no issue simultaneously on both cabs while using the extra outputs from the splitter.


Any advice to get a 3rd output for a viewing monitor and possibly a 4th output for a capture card would be greatly appreciated!