Thank you everyone for the suggestions, I have been googling more about them all day
I've never heard of a constant current diode. I did some reading on them but didn't find much info. From what I did find, it looks like 10mA is about all you can run though one? I am looking for around 40mA for each string of 4 leds.
I did look into buck/boost converters. Havn't seen the perfect one yet though
I looked into buckPuck LED drivers, but most are constant current, and for 72 strings of leds, I don't know how to make use of one.
or any constant current device for that matter., unless I used 72 of them, and I don't have room for that.
gramo - Your zener diode circuit has me interested, yet scratching my head. I don't understand how it works. I had though about a way to use a zener, but couldn't figure out how, or if it was even possible. I'm gonna sleep on it and look at it more tomarrow.
I found this site:
https://www.muzique.com/schem/lm317.htm
It says to make sure input on a lm317 is atleast 1.5v greater then output. I though you needed closer to a 3v seperation? Who is right? If I could get away with 1.5v, I could possibly regulate the supply at 9.5v. But that also puts me very close to the total forward voltage of the leds.