[Mike Rivers]

On 10/27/2010 1:35 AM, Jay Ts wrote:

I did remove the scope trace photos from my website some months
ago when I was cleaning things up on the server. If it is really
important for you, let me know and maybe I can email them to you.

No big deal. I understand now what you're talking about.

I know how hard it is to design hardware, software, or
any combination of them that is "perfect", but the problem
is that imperfections (bugs or design failures) in complicated
systems such as computer systems can lead to huge problems for people.

That's for sure. However, this particular problem is one
that's really only become a problem because of the practice
of trying to squeeze the most bits all the time out of a
digital recording, a practice which, in itself, results in
distorted audio. The fact that it's a little more distorted
because of inter-sample clipping is just icing on the mud pie.

Lately I've been using my Audiophile 2496 mostly as a test instrument,

And now you know why there are sound cards you possibly have
never heard of that costs times and more what the Audiophile
2496 does, and are uses in laboratory test setups. I think
it's really cool that i can use RightMark with my Lynx L22
or Mackie Satellite and get frequency response plots and
distortion analysis with greater precision and resolution
(as well as publishable graphics) than I can with my H-P 334
distortion analyzer or NTi Minirator/Minilyzer combination.
I don't need to swear by those measurements, and it's rare
that I can actually hear what I can see by making them.

If I was designing circuits to bring to market, I'd be sure
that I had test equipment capable of showing me what I
needed to know without lying to me. If a $100 consumer sound
card won't cut it, I'd get what I needed to get.

It's not always allowable to "just turn it down", because I need
to test things at 0 dbFS.

True, your test equipment must always be better than what
you're testing. That's a fundamental principle of metrology.

In any case, I think people should not need to analyze,
understand, and correct for odd behaviors of their "professional"
quality audio cards.

"Professional" is just a marketing word. But if you're going
to be a professional, you should understand what you're
working with, know its limitations, and know what you can
get away with and what you can't.

a Palm Tungsten E (not even their top of the line model)
was able to handle the waveform correctly!

Sometimes the older technology just did things better, not
because they were trying to (I doubt that the Palm designers
gave any thought at all to the audio playback quality), but
because they didn't take the same shortcuts that modern
designed do.

TASCAM, with their -10 dBV nominal operating level, was
really on to something back in the late 1970s. By using a
+/- 15V power supply and setting the nominal operating level
at +/- 0.32V, more than 20 dB of headroom was no sweat. With
today's gear still using the same, or lower, power supply
voltages, a nominal +4 dBu output level has a harder time
making it to +24 dBu (20 dB of headroom). But it looks good
on the spec sheet, and most users can live with it.

--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson