[sdiy] LED current source needed for 'digital' outputs?

[Justin Owen]

-----Original Message-----
From: Mattias Rickardsson [mr at analogue.org]

> Vref sounds like some reference voltage... I wouldn't draw varying currents
from such delicate things. But from supplies it's cool. :-)

-----Original Message-----
From: MTG [grant at musictechnologiesgroup.com]

> Well Vref wouldn't be my first choice. Do you have an positive voltage 
available that's not a reference?

By Vref I mean a buffered LM336 - which have been just fine for every job I've thrown at them so far...

What are the concerns?

Thanks,

- J