I looked around and couldn't find an answer - The AVS came with a 1 amp power adapter.  When using 2 controllers with longer cables (10+ feet) it does not recognize the second controller.  Use shorter cables, and they both work.

I had the same issue with My retropi until I upped to at least a 2.1A power supply.  Once I used that, cable length didn't matter, and it can now also use an xbox 360 controller without issue.

Possible same issue on the AVS?  I'm worried about using anything other than the included 1A power supply, don't wanna fry anything.  I love my AVS!!   

Using a higher amperage adapter shouldn't pose any threat, as electronics will only pull the amount of amperage that they need. When matching up power, the voltage always has to be 1:1 with what's required, but the amperage only needs to be at least equal to what's required--it can be higher without any detriment or danger to the device. In this instance, if your theory is correct, the AVS should pull down power at the higher amperage when extension cables are attached to both controllers. As a final bit of testing, have you tried connecting an extension to controller 2 and leaving controller 1 using its regular cable? It's possible that what you're experiencing isn't a power issue but some previously unseen issue with port 2 (and/or 3 & 4) to not be able to use/recognize extension cables. Hope this helps!

I'm not using extensions, just 3rd party NES controllers for cable length.  But having any combination of offical NES controllers / 3rd party controllers / port 1 / port 2 works great until I have two 10' controllers in.

In fact, when there are two of the 10' controllers plugged in in works for a second, then quits, I should of clarified that.

I'll try the 2A / 5V power supply tonight.  Thanks for the reply! I never knew that the only thing to worry about was Volts as long as minimum amperage is there.  Huh - learn something new every day.  Cool!

Oh - so that means things like "fast" phone chargers are just higher amperage.  Neato.   

 

To me, the fact that both long-cabled controllers work, however briefly, then "die" until the system is reset definitely sounds like a power issue to me.  I had a similar issue with USB speakers on an old computer and only resolved the issue by running them through a powered hub; before that point, whenever sound would spike suddenly or get loud for too long, the speakers would totally shut off and refuse to work until you rebooted.  Whether this is due to the AVS not being able to draw enough power to support them or something else (like the AVS having tighter tolerances for the amount of power available at the controller port than the original NES), I can't say.

As for "fast" phone chargers, in some cases it is just a matter of simply plugging your phone/tablet/whatever into a charger with higher amperage.  My later iPhones charge noticeably faster when plugged into a 2.1A port normally meant for a tablet.  However, in other cases, such as with Qualcomm's patented "Quick Charge" technology, the amperage doesn't matter as that process actually charges faster by raising the voltage temporarily.  It all depends on how your device is manufactured.

Hope it works for you!  If not, you might want to send an email to the AVS support box and let them know what's up.  It's possible that this is something that could be addressed via a firmware update if a higher amperage power supply doesn't take care of the issue.