Not much has been said about power supplies, far as I know just a "USB 5V supply"... so I started with various chargers I had kicking around, found 'em unwilling to remain within 5-10%, even the 3 amp'ers, and that just bugged the tar out of me.
So, got me a 2.5A $20 regulated switcher, cut off the DC plug cord, and replaced it with a 6' USB mini. set it for 5V,...
Now, my touch of OCD is relatively happy, considering 4.94-5.01 closer to perfect than 4.69-4.81, and a consistent 4.98 beats the heck out of 4.74... jest muh ohpenyun. (although I suspect this electronics doesn't care all that much... I do.) 'Course that's enough to forward bias 4 junctions....
After all, Red seems a good stable design, and I felt it didn't need 2nd rate juice...
Always said that 1% was better than 6%... unless you're talking beer