If I remember correctly the video amp for the Jpac is made just for older Jpacs that don't have the video amp built in. I don't think you would be able to us it independently.
This is an insert from the Ultimarc Page./*****************************************************
This is a
standalone video amplifier which converts the 1 Volt output from a VGA card into 4 Volts required by most arcade monitors.
The circuitry is exactly the same as that used on the J-PAC and uses a high-bandwidth video amplifier chip. It provides an easy way of fixing a
"dim" arcade monitor installation by boosting the signal input to the same level as a "real" game board.
*****************************************************/
//end
It does say that it amplifies the video signal from the VGA card from 1v to 4v. From my understanding the reason that the display on the arcade is slightly dim is due to This. I willing to try this as soon as I get a hold of one.
I wonder on what's the worst harm that it can do to my monitor, if I screw up. Maybe Andy can fill us in with this or anybody with some info. I'm also experimenting about whether the 3deep software can also improve my setting. Maybe the gamma correction might help with the appearance.
As for flickring, I was actually impress with the result of it than on my TV. Not much flickring and the text was actually readable and not to harmfull on the eye (at 800 x 600). It's just that it was a bit bright/dim at the same time. I was playing with it for few hours and actually satisfied with the preliminary result. But of course beauty is on the eye of the beholder.
What ever my venture will result on, I will certainly let everyone know, and will provide some picture of my result.
BTW I dont know anything about monitors, frequency, etc. I dont even work in the computer field, so please correct me or give information in regards to this matter.