[sdiy] reducing amount of bits

[john mahoney]

>  For example: If we had a 16 bit word and only used the top four bits (
MSB
> down ) to feed the DAC would that be it?
>
>
> Michael

Electrically: Set the unwanted bits to zero. (Is that Ground or -V?)
Logically: Do a Logical AND with each sample and (to use your top 4 bit
example) F000 hex.

This page is quite informative:
http://www.tc.umn.edu/~erick205/Papers/paper.html#dacs
It's focused on Compact Discs but, as Ed McMahon might have said, it has
"Everything you could POSSIBLY want to know about digital audio!!!"
--
john