Arcade setup video splitting

[system11]

I was hoping to use an Extron RGB splitter/amp in-line on a JAMMA cab so that the video could be recorded/streamed/put on other displays without getting in the way of cab operation.

I built an ugly test harness, but I've hit a snag. The Extron isn't hugely happy about the high voltage level of JAMMA games, but if you switch it to AC coupling mode it can cope (I could instead stick some voltage dividers in front of it). However, all the outputs are VGA RGB level, which leaves the normal arcade monitor looking pretty dark and washed out.

I know some people essentially just splice a feed out and plug it straight into an xcapture, but won't that also result in dimming and additionally overload the xcapture a bit, which according to the manual is rated for VGA/Scart levels of RGB? Would sticking some voltage dividers in front of that still work and result in less dimming?

Are there any splitter/amp devices or circuits I could build which accept and output 'full fat' levels of RGB as used by arcade cabs?

Naturally, I was hoping it would be easier than this. I want to get a 'proper' result - so the point of the exercise is to take one JAMMA RGB signal and turn it into one JAMMA + one VGA.

[system11]

Traces on the scope from top to bottom:
VGA level output measured from extron, suitable for xcapture.
JAMMA level input to the monitor
PCB output

If you take all that out and plug the PCB into the monitor directly, it looks just the same.

Mission accomplished, I just need to turn that rats nest into an actual usable thing.

[DanAdamKOF]

Is the end result dependent on both connectors being hooked up to something (jamma level output into monitor, vga level into capture card), or can you connect and disconnect the capture card and not have it affect the monitor?

[Sumez]

I just split the R, G and B signals through a 220 ohm resistor each from a JAMMA extender cable I had lying around anyway. My capture card eats it gladly (the image is a little shaky compared to consoles, but nothing horrible), while the image on the arcade cabinet looks completely unaffected.

[system11]

Is the end result dependent on both connectors being hooked up to something (jamma level output into monitor, vga level into capture card), or can you connect and disconnect the capture card and not have it affect the monitor?

Sorry for the delay, you can connect as many sources as you like and the signal is unaffected.

However, what you need to understand is there are resistors before the distribution switch, and there's an amp after it before the monitor. The signal is being lowered and then raised again because the switch doesn't cope well with arcade level RGB. I haven't really worked on it since making the wire prototype.