bitsteam is another cost over quality thing afaik....

the way that a multi bit dac works is by the 16 bit data word being used to switch a constant voltage through a bunch of precision resistors whose outputs are summed to provide a varying level which is the raw analogue signal.

getting these resistors to provide the correct values (down to 2.2 / 2^16 or 0.000033569 of a volt if your maximum output level is 2.2v) is expensive and leads to various qualities of the same dac e.g. the bb1801 (k)??? and famous tdc 1541 double crowns etc. which are horribly expensive but have spot on perfect resistor values. (if i understand things correctly)

a one bit dac is a lot cheaper to produce as you don;t have to faff about with laser trimming 16+ resistors etc. it can just be stamped out on an i/c. once again quality sacrificed on the altar of profit.

cheers

julian