What does a higher bit DAC do?

[Dubb]

bit depth != bit rate.

surprised at how many people (who I would expect to know better) fumbled on that one.

read nanostuff's post. but yeah, oversampling DAC's are a different story (I think they're overrated) . I wouldn't pay much attention to 1 bit or 24 bit, just read reviews and listen and take the one that sounds better.

 

[Mark R]

Originally posted by: aphex
Well the reason i ask, i've been looking at car headunits...

Some speak of a 1-bit DAC (Alpine 9857), while others refer to a 24-bit Brown Burr DAC (Premier 880prs), and yet others just say 24-bit DAC (for DVD-Audio)

This is a problem of marketing departments using technical terms.

As stated earlier in the thread, the number of bits in a DAC determines the precision of the output - a 4 bit DAC can produce 16 different analogue voltages, a 16 bit DAC 65536 different voltages and a 24 bit DAC 1677216 different voltages.

CD-audio is recorded at 16 bit resolution. You should get perfect reproduction with a DAC with 16 bit resolution or better. DVD-audio can be recorded at 24 bit, hence DVD-audio players will usually have 24 bit DACs.

the term '1-bit' DAC is misleading. It describes a particular design of DAC, called a delta-sigma modulator (Marketing literature may also call this a bitstream converter). It doesn't tell you anything about the precision or quality of the overall DAC system. You can get 16 bit, 20 bit and 24 bit delta-sigma DACs. Indeed, the vast majority of audio DACs available today are delta-sigma DACs.

(I'll skip the theory of delta-sigma modulators, but they allow you to make a very high quality DAC out of a simple 1 bit DAC and a bundle of digital/analogue processing circuitry). It gets even more confusing, because some of highest-end audio DACs actually use delta-sigma modulators with 3 or 4 bits!

Burr Brown, used to be a company that specialized in making high quality DACs and ADCs, serving the mid-high-end and very-high-end markets. Texas Instruments bought them out in 2000, but retained the Burr-brown name on the old Burr-brown products. TI haven't use the Burr-brown name on their new products, and much of the BB technology has mingled with TI technology. So, although Burr-brown made products serving the high end, their products are relatively old technology, and modern products (either from TI, or other manufacturers) may be better.