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Thread: RGB voltage levels

  1. #1
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    RGB voltage levels

    Hey guys

    So, I got a little 13" PVM recently and I connected my supergun to it. It works fine, it looks beautiful. However, for whatever reason, I read that typical RGB voltage output from a JAMMA board is about 3-5V on the RGB lines. But reading my PVM instruction manual, it says that the PVM expects 0.7V p-p (peak-to-peak?) on the RGB inputs. These inputs are 75-ohm terminated (whatever that means). So am I feeding too much voltage to the RGB inputs of the PVM? can/will it get damaged? should I put resistors between the JAMMA RGB outputs and the PVM inputs?

    Thanks for the guidance, searching for this on google was not very conclusive.

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    Kyokugen's Student
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    Most superguns have the resistors built in. I use 220 ohm for JAMMA boards on my PVMs. One resistor each on R G B and sync.

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    Quote Originally Posted by aha2940 View Post
    Hey guys

    So, I got a little 13" PVM recently and I connected my supergun to it. It works fine, it looks beautiful. However, for whatever reason, I read that typical RGB voltage output from a JAMMA board is about 3-5V on the RGB lines. But reading my PVM instruction manual, it says that the PVM expects 0.7V p-p (peak-to-peak?) on the RGB inputs. These inputs are 75-ohm terminated (whatever that means). So am I feeding too much voltage to the RGB inputs of the PVM? can/will it get damaged? should I put resistors between the JAMMA RGB outputs and the PVM inputs?

    Thanks for the guidance, searching for this on google was not very conclusive.
    It will just be too bright in the worst case.

    The PVM terminates inputs to 75 ohms (sinking to ground), and many "standard" RGB outputs expect 75 ohm series termination to match it (on most consoles).

    RGB outputs made for arcades are seldom terminated this way, and often use a higher value (like 220 ~ 330 ohms). With the wrong termination, a different voltage divider is created.

    If it's too bright, you can throw resistors in series.

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    Quote Originally Posted by mikejmoffitt View Post
    It will just be too bright in the worst case.

    The PVM terminates inputs to 75 ohms (sinking to ground), and many "standard" RGB outputs expect 75 ohm series termination to match it (on most consoles).

    RGB outputs made for arcades are seldom terminated this way, and often use a higher value (like 220 ~ 330 ohms). With the wrong termination, a different voltage divider is created.

    If it's too bright, you can throw resistors in series.
    Thanks for the help, guys. Now I am sure the monitor will not get damaged. The image looks fine to me, so I do not think I need the extra resistors, just wanted to be sure.

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