Driving 8x1W & 4x2,5W LEDs (LM317???)

to mneary: THANKS A LOT best post I get so far

may I ask another queastion regarding LM317...?

will this work, or how do I drive multiple arrays of LEDs 20mA by current?

I want it universal, cause I want to switch the diods... cannot put a resistor in front of each string, cause if there will be 4xwhite LEDs (3.3V) or 4xred (2.1V) is a difference... but if you know a better method, please tell me...

but I wonder if the LM can drive multiple strings and if the current split 1:1

**broken link removed**

Sorry, LED strings in parallel (even the same type) don't share current well. Different types in different strings are worse.