[linux-audio-user] External DAC for mastering use?

[Jussi Laako]

On Thu, 2004-03-18 at 19:41, Mark Knecht wrote:

> Of course! But that wasn't my point. My point was he should really be 
> using a 24-bit external DAC. Of course, it's more money...

Having 24-bit DAC for just the sake of having 24-bit DAC isn't good
reason. I have a high quality external DAC connected to S/PDIF of my
M-Audio Delta1010 (which has 24-bit DACs in external box). And I really
think that my external S/PDIF connected DAC sounds better, although the
data stream is only 16-bits. It has high quality digital interpolation
filter (8x / 16 -> 20 bits) and high quality true multibit DAC connected
to it. Also the analog reconstruction filter is made of top quality
components. Single bit (Sigma-Delta and the like, PWM) DACs tend to have
IMD. I have designed two external audio DACs, and I still like the
multibit one most. Of course, precision multibit DACs cost significantly
more compared to "single bit" ones.

With 24-bit DACs you are anyway wasting multiple bits, because you
practically can't have ~140 dB S/N ratio for audio bandwidths. You are
most likely to get little over 100 dB. So having 16-bit interpolated to
18 or 20 bits is usually enough (unless you have really quiet studio).

Conclusion? High quality S/PDIF connected converter can be a good
option. Just requires that computer's S/PDIF output is properly
implemented.


-- 
Jussi Laako <jussi.laako at pp.inet.fi>