I think it would be a fantastic idea
So what your proposing is a standard Video Amplifier circuit that could be used externally or internally for any given console?
Would the idea be to have a number of standard circuits made (making the cost lower) so that you can easily use it on any console? (If so please count me in for quite a few!) Or were you thinking self build?
Just one question - would you need to use an oscilloscope in order to set the pots gain correctly for each specific console? I only ask as I hate adjusting things by eye, as im forever thinking 'just one more tweak'. Maybe would it be possible to have a space for a fixed resistor instead of a pot, for those people who just want to use it internally for one specific console? Then we could have a small list of the correct resistor value to use for any given console - if that makes sense!
btw was it me you were thinking of in regards to the N64 RGB Driver not working as expected? I only ask as it does work fabulously if I dont connect the amp up to the ENC-NUS chip (So lose RF/Composite/S-Video) but its worth it for the great RGB picture you get. I am just hoping I havent put you off designing more amps in the future - as the N64 RGB driver does work great for its intended purpose of amplifiing the RGB signals to the correct level.
I do agree though that it would be nice to leave the consoles original video circuit intact if possible (I didnt enjoy removing those surface mount resistors!) and I think the idea of just tapping the RGB from the video chip and connecting it to the output withing messing with any other parts is quite desirible (Although I remember you saying that this was possible with normal components but would make the amps component count alot higher)
Your hard work and effort is really appreciated Viletim