I was wondering which power supply out of these two that I have would be better for my Hi-Def NES in the long run. Surprisingly, they both work on the NES but of course not on my Genesis Model 1, I'm guessing because of the new modern fuse inside of the Hi-Def NES kit? Anyway, here's a pic of the two power adapters. Can anyone tell me which one is better to use for the long run on my Hi-Def NES? Thanks

http://imgur.com/a/GS1Uc...
 

The left power supply is AC 9V. The right supply is 12V DC positive tip. AC is fine for the NES but I stopped using them because it will nuke the regulator on just about any other game console you plug it into. Extra volts will heat the regulator more but assuming it has an adequate heat sink you're okay. Still no reason to add extra stress to 30 year old components.

Genesis Model 1 is 9V negative tip so either adapter is a bad idea. Reverse polarity won't work. AC may fry something. Feeding the regulator AC causes massive power ripples on the VCC rail and it will sink more than double the RMS current during the positive cycle. You'll put incredible stress on the regulator and filter cap, and add awful line buzz to the audio. Some regulators can tolerate reverse bias (they still output 0V in this state) but others can't.

AC input is suicide unless the console has a full wave bridge rectifier and filter cap prior to the regulator. NTSC NES contains the necessary components.

Yeah I definitely wasn't going to use either one of them for my Genesis Model 1, just for my Hi-Def NES. If you say the extra voltage adds more heat, then I'll avoid that one for sure. The bottom of my Hi-Def NES where the kit is seated gets really hot as it is  
I'm still surprised that the NES seems like it can power on with almost any plug I throw at it, where as the Genesis is much, much more picky.

So is there a discernible different between 1080p of the hi def NES and the 720p of the RetroUSB AVS? I don't want to wear out my Hi def NES since it does draw more power (and it's 27-28 years old - top loader).

I am, primarily, using an Everdrive N8, so I don't know if there's any comparability issues to worry about game wise.

I have no idea, but I stick with the original NES power supply that came with the system.

I'm not worried about wearing out my NES anymore because I had all the power capacitors replaced with new ones and the Hi-Def NES kit no longer uses the original 7805, the kit itself has its own "modern" voltage regulator on it. So basically, the essential parts of my NES that would wear out over time (power caps, voltage regulator) are only 6+ months old now, rather than 30+ years old.

And yes, the 1080p resolution is totally worth it. Super sharp, crisp, clear and deeper blacks. I've never tried an AVS in person but I've set my Hi-Def NES to 720p just to see the difference and there really is a big difference between the two resolutions. A lot of people say that 720p is the sweet spot though because it's 240p x 3, dk what the big deal is about it except that I think it means that platforming games will scroll horizontally/vertically more smoothly or something, I don't really know for sure though tbh. All I know is that 1080p looks amazing on my Hi-Def NES compared to when I tried it on 720p.

As for my power supply conundrum, I'm just going to continue using my Creative PC speakers 9V 700Amp power supply. I've had no problems whatsoever with it ever since I started using it for my NES, and I've been using it for months now. I had more problems when I used an aftermarket (Yobo) Genesis/(S)NES power supply for it that was rated 9V 1.2amp. A lot of times my NES would not power on when I used that power supply. I haven't had that issue ever since switching over to the Creative PC speakers power adapter. The Yobo power supply is most likely outputting much less power than what is rated on its sticker.
 

Kk, I had the capacitors replaced when I got the mod done, so that's comforting

Glad I could help