[Arny Krueger]

wrote in message
oups.com...

You guys apparantly missed the text that unfurls when you click 'more'
on the descriptor.

Can we just buy him a cheap microphone and let him make the video over
again, this time in a sensible way?

Of course he's probably using a camcorder which has a mic.

So what's his point - that he's figured out how to post video without audio?

Pretty cool, an audio demo with no audio when there easily can be and should
be.

Are we in the Twilight Zone? ;-)

Remember, I'm just pointing this out, I didn't
originate it.

Well, that improves my opinion of you! ;-)

I have a Lavry DAC, and I think it sounds quite good.

Well, yeah! ;-)

This dude is claiming something about how the sample rate delivered to
the DAC chip doesn't change at all when changing from 'wide' lock mode
to 'crystal lock', indicating asynchronous sample rate conversion is
taking place.

His alleged test is full of holes.

What I get is that may be using one of them new-age fancy o'scopes that has
an on-screen frequency counter display.

It says 117.181 regardless of some switch setting.

Or maybe the photography is so bad that I can't really read the counter
reading off the screen accurately enough to be useful.

I'd like a few more digits displayed, but as I point out below, his method
is unecessarily complex.

How this results in "operation contrary to the manufacturer's claims"

There is no guarantee that he's probing something that is ever at exactly
the word clock frequency. After all, if he's as good of a technican as he
is a commercial maker... ;-)

Besides, when a DAC is processing a SPDIF signal, the DAC's clock should be
exactly the same frequency in any mode that results in an output signal. The
DAC clock frequency should exactly correspond to the clock frequency implied
by the SPDIF signal.

If there is a question about the clock frequency of an ADC, just convert a
test signal with a very precisely known frequency that is within the range
of the ADC. If the ADC clock is wrong, then you can determine it by
analyzing the digitized signal using standard DAW software.

No test equipment is required other than the signal source, which can be as
simple as a CD player playing a test CD you made with standard DAW software.
OK, there will be some slight ambiguity because of slight variations in the
clock in the CD player, but it will be well within the range of variations
that make no audible difference.

So his whole demo is unecessarily complex, in addition to being impossibly
badly made.

Is he trying to sell something? If so, I wouldn't buy it on a dare because
he isn't even a competent technical sales guy, let alone a competent design
engineer.

I don't get.

There may be nothing of merit to get! ;-)

I was hoping one of you could
shed some light. A scope certainly isn't the best device to make very
precise frequency measurements.

I think he used a scope with a frequency counter plug-in. If the video were
worth squat, we might be able to figure that out from what we could make out
from the video.