4 Jul
2006
4 Jul
'06
4:40 a.m.
Ethan Dicks wrote:
I was just hoping to upgrade my dodgy ladder with a
more precise one
without resorting to additional cables and powered circuits. I seemed
to have opened a can of worms.
:-)
I thought that pretty much all DACs are ladder-based internally anyway, just
with far finer tolerances than the typical "bag 'o resistors" hack. In other
words, by fine-tuning a homebrew ladder and using suitable buffering, you
could probably get something pretty respectable running.
I stumbled across a few pages on DACs and ADCs a while ago:
http://www.allaboutcircuits.com/vol_4/chpt_13/1.html
thinking about it, I wonder if the resistor packs often found in old equipment
are any finer tolerance (or at least more closely matched) than using seperate
resistors? If you have any scrap ones laying around it might be worth
investigating.
cheers
Jules