Re: [ARSCLIST] Shopping for AD/DA

[Don Cox <doncox@xxxxxxxxxxxxxx>]

On 11/07/07, phillip holmes wrote:

> I know you weren't. That was merely an "amen" for Bob. Most decent
> ADCs can give good results, if they are used correctly. That's why I
> don't like those "restorations". They "put lipstick on the pig" and
> the result is unacceptable for me and the pig.
> 
> There was a great article about Pro-tools a while back. It explained
> how all that manipulation in the digital domain gives such a bad
> sounding product because every manipulation of the original signal
> looses bit depth (or something like that---I'm an idiot about
> digital). Phillip

If you have access to Photoshop, you can see a visual equivalent.

Load in a color photo, ideally one that is too dark. Go to
Image->Adjust->Levels (or "Adjust Lighting->Levels" in PH Elements).

You will see a histogram showing 256 levels of brightness.

Adjust the sliders, which is the equivalent of adjust levels in audio,
so that the photo looks better.

See how the histogram breaks up - there are no longer 256 levels. The
gradation is now jumpy.


This is because, to change levels, the computer must map some pairs of
levels onto single levels. The more steps you have to start with, the
less trouble this causes. 

Regards
-- 
Don Cox
doncox@xxxxxxxxxxxxxx