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Supergun or circuit for simple (?) conversion of high amplitude RGB (Arcade) to low amplitude RGB (VGA)?

S

sofakng

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I'm currently using a CRT TV in my MAME arcade cabinet and I want to connect some arcade PCBs. (i.e. Neo Geo MVS)

The TV accepts component video (YPbPr) and I'm using an RGBHV (VGA) to Component transcoder (Crescendo TC1600). This is connected to a MAME PC using CRT Emudriver to output 15 kHz signals over DB15/VGA which is then converted to component.

Assuming I'm going to use a JAMMA breakout cable and have each of the signal wires (RGBs), how can I safely reduce the arcade RGB high amplitude (2-5v p-p) to a safe level (0.7v p-p) for my VGA transcoder?

I'm decent at soldering but can't wrap my head around understanding electronics. I think I need to reduce voltage and buffer (THS7374 amp?) the video but I'm not sure how to design the circuit (and what/how 75 Ohm termination is required, etc).

Thanks for any help!
 
Thanks a bunch! It looks like it's out of stock but I'll send him an e-mail to see if he is still producing them.

I also need to look into how to convert the audio signal...

(BTW - I've also pre-ordered a HAS from you a while ago... thanks for everything you do!)
 
Yeah, I'm building one of those too actually (haha) along with buying a HAS from RGB, but they require the JAMMA PCB to be connected to the supergun.

I'm looking for a solution that I just connect the RGBS wires directly and get an output.

Arcade PCB -> JAMMA harness -> (RGBS high-impedance to RGBHV converter low-impedance) -> Transcoder...
 
Did you see the video schematic in the Minigun download?
 
Yes, is it the only labeled "THS7374 CIRCUIT" ?

It looks like it's just some capacitors and resistors so it looks easy enough to build. Although, it would be a bit messy on a prototype board due to the number of components?

If that's the entire circuit I need then I will definitely consider building it.

However, the Irken Labs Tri-Sync Helper definitely looks absolutely ideal. It even converts RGBS to RGBHV. The only thing I noticed is that it doesn't have potentiometers so I'm not sure how it reduces incoming voltage or how you can set the proper level?
 
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