Hey,
I'm enjoying my groovymame setup a lot. There's nothing like playing retro games on a CRT !
The only thing bugging me is the lack of an universal solution for perfect screen size adjustments. I set up my TV for CPS 1/2 games since I'm a huge fan of these systems, and for the most part the other systems are not stretched enough horizontally. Not a big deal, but some Midway and Irem games are stretched too much vertically (R-Type, MK...) and a good portion of the screen is hidden. From what I've read there's not much to do about it and the only solution is to have a set easy to access controls to do it on the fly for each system.
Anyway, I'm wondering about another minor problem that might have an explanation or solution.
I really like the Konami game Violent Storm, and for some reason it doesn't look great on my CRT (one of the last Sony Trinitron models) : the scanlines are barely visible, when on another game running on the same system, Mystic Warriors, the scanlines are well defined. Is this normal ? Here are some pics :
https://photos.app.goo.gl/QSvrM1DEMDXoSSMY7