What's the use of a 192 kHz sample rate?

On May 3, 3:35 pm, Oli Charlesworth <ca...@olifilth.co.uk> wrote:
> On May 3, 5:26 pm, dpl...@radagast.org (Dave Platt) wrote:
>
>
>
> > There may be _some_ justification for it, as it eliminates the need to
> > place the knee of the anti-aliasing filter anywhere near the range of
> > frequencies that one _can_ hear.  One of the criticisms made against
> > CD is that the sharp filtering which must be done at around 20 kHz can
> > cause artifacts which may be audible to some listeners, either due to
> > "pre-ringing" (with a symmetric FIR low-lass filter) or a frequency-
> > dependent delay and "smearing" of transients (with an IIR filter).
>
> > These effects can be moved up to higher frequencies, and prevented
> > from having effects in the human hearing passband, by increasing the
> > sampling rate.
>
> Indeed.  But this problem is largely solved by oversampling at the
> DAC, without requiring an increased sample rate at the storage-medium
> level.

And how exactly do you over sample at the DAC without a filter?

Rick

On May 3, 9:28 pm, rickman <gnu...@gmail.com> wrote:
> On May 3, 3:35 pm, Oli Charlesworth <ca...@olifilth.co.uk> wrote:
> > Indeed.  But this problem is largely solved by oversampling at the
> > DAC, without requiring an increased sample rate at the storage-medium
> > level.
>
> And how exactly do you over sample at the DAC without a filter?

And where exactly is he claiming otherwise?

Oversampling DACs have been the rule for well over two
decades.

On Sat, 03 May 2008 03:28:49 -0400, Randy Yates <yates@ieee.org>
wrote:

>rickman <gnuarm@gmail.com> writes:
>
>> If it really is a waste of time and money to use 192 kHz ADC and DAC,
>> why do you think they would do it?  
>
>Greed. They think that the general public is dumb enough to buy into
>the lie that they really need such a system and would then spend lots of
>money repurchasing what they already have.

Hi Randy,
  you remind me of the transistor radios when I was 
kid (back when the air was clean, and sex was dirty).
If a transistor radio manufacturer could claim that 
their radio had had more transistors than their competition, 
then that was strong "selling point".  As such, 
some transistor radio manufacturers were using transitors 
in place of the diodes needed in AM demodulation.
So instead of having four transistors and one diode, 
those manufacturers could claim "5-transistor performance",
in the hope of increasing sales.  Ha ha.

See Ya,
[-Rick-]

In article <96fq141o7bh82pho575op2q1upefkq61bv@4ax.com>,
Rick Lyons  <R.Lyons@_BOGUS_ieee.org> wrote:

>Hi Randy,
>  you remind me of the transistor radios when I was 
>kid (back when the air was clean, and sex was dirty).
>If a transistor radio manufacturer could claim that 
>their radio had had more transistors than their competition, 
>then that was strong "selling point".  As such, 
>some transistor radio manufacturers were using transitors 
>in place of the diodes needed in AM demodulation.
>So instead of having four transistors and one diode, 
>those manufacturers could claim "5-transistor performance",
>in the hope of increasing sales.  Ha ha.

I've read that there were some "7-transistor" radios, in which one or
two of the transistors were soldered to unconnected pads on the board.
They had no function at all, and they were often "floor sweeping"
parts known to be defective... but they _were_ transistors and were
present in the radio, and so the radio could be advertised (legally if
not all that ethically) as a "7-transistor" model.

-- 
Dave Platt <dplatt@radagast.org>                                   AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
  I do _not_ wish to receive unsolicited commercial email, and I will
     boycott any company which has the gall to send me such ads!

On May 4, 1:14�am, dpl...@radagast.org (Dave Platt) wrote:
> In article <96fq141o7bh82pho575op2q1upefkq6...@4ax.com>,
> Rick Lyons &#4294967295;<R.Lyons@_BOGUS_ieee.org> wrote:
>
> >Hi Randy,
> > &#4294967295;you remind me of the transistor radios when I was
> >kid (back when the air was clean, and sex was dirty).
> >If a transistor radio manufacturer could claim that
> >their radio had had more transistors than their competition,
> >then that was strong "selling point". &#4294967295;As such,
> >some transistor radio manufacturers were using transitors
> >in place of the diodes needed in AM demodulation.
> >So instead of having four transistors and one diode,
> >those manufacturers could claim "5-transistor performance",
> >in the hope of increasing sales. &#4294967295;Ha ha.
>
> I've read that there were some "7-transistor" radios, in which one or
> two of the transistors were soldered to unconnected pads on the board.
> They had no function at all, and they were often "floor sweeping"
> parts known to be defective... but they _were_ transistors and were
> present in the radio, and so the radio could be advertised (legally if
> not all that ethically) as a "7-transistor" model.

i thought i remembered even "10-transistor" radios.  i didn't know
this about the bogus addition of transistors (when i was older and
reflected on it, i just thought that it meant more stages in the RF,
IF, and AF signal chain or the use of some push-pull pairs.

if they were so bad as to solder in unused transistors, they should
have been clever enough to route the pads into the circuit board in
some non-functional way (leaving the transistor shorted and hanging
offa something, so it at least "looked" like it was being used for
something.

it's sorta like when someone slips in superfluous instructions in
their code so that they can later prove that it wasn't developed
independently if they find someone else selling a product with their
code in it.

r b-j

Rick Lyons <R.Lyons@_BOGUS_ieee.org> writes:

> On Sat, 03 May 2008 03:28:49 -0400, Randy Yates <yates@ieee.org>
> wrote:
>
>>rickman <gnuarm@gmail.com> writes:
>>
>>> If it really is a waste of time and money to use 192 kHz ADC and DAC,
>>> why do you think they would do it?  
>>
>>Greed. They think that the general public is dumb enough to buy into
>>the lie that they really need such a system and would then spend lots of
>>money repurchasing what they already have.
>
> Hi Randy,
>   you remind me of the transistor radios when I was 
> kid (back when the air was clean, and sex was dirty).
> If a transistor radio manufacturer could claim that 
> their radio had had more transistors than their competition, 
> then that was strong "selling point".  As such, 
> some transistor radio manufacturers were using transitors 
> in place of the diodes needed in AM demodulation.
> So instead of having four transistors and one diode, 
> those manufacturers could claim "5-transistor performance",
> in the hope of increasing sales.  Ha ha.

I never knew that! I remember the "N-transistor radio" slogans of the
mid to late 60s (if I recall correctly). Like Robert, I distinctly
remember "10-transistor" radios.

Just to go totally off-topic, this also reminds me of a couple of my
early electronics love affairs. Back in circa 1966 or 67 (about the time
the Beatles' "White Album" came out) I got a really cool device for
Christmas (or birthday - they're 8 days apart): an AM/FM radio AND a
really neat miniature reel-to-reel mag tape recorder! Oh how I loved
that radio! Being in the Panama Canal Zone at the time, it allowed me to
have some contact with the rest of the world - I remember first hearing
and falling in love with Paul Mauriat's "Love Is Blue" and the Beatles'
"Revolution #9" with that radio ("number 9, number 9, number 9, number
9...They are standing still"). I had discovered a whole new universe!

During the same period, I also acquired (via a very painful advance on
my allowance for several weeks) a Sears walkie-talkie (100 mW, channel
14). Oh how I loved that device as well! I used to ride around on my
bicycle trying to find the best place on the base (we were living on
Howard AFB in Panama Canal Zone) for reception. I remember enjoying
hearing even the cacophony of noise that resulted when the skip would
roll in and I'd hear (dozens of?) radio signals fading in and out. 

OK, so much for my memory dump... Thanks for listening!
-- 
%  Randy Yates                  % "...the answer lies within your soul
%% Fuquay-Varina, NC            %       'cause no one knows which side
%%% 919-577-9882                %                   the coin will fall."
%%%% <yates@ieee.org>           %  'Big Wheels', *Out of the Blue*, ELO
http://www.digitalsignallabs.com

"Randy Yates" <yates@ieee.org> wrote in message 
news:m3hcde7cbo.fsf@ieee.org...
> Rick Lyons <R.Lyons@_BOGUS_ieee.org> writes:
>
> During the same period, I also acquired (via a very painful 
> advance on
> my allowance for several weeks) a Sears walkie-talkie (100 
> mW, channel
> 14). Oh how I loved that device as well! I used to ride 
> around on my
> bicycle trying to find the best place on the base (we were 
> living on
> Howard AFB in Panama Canal Zone) for reception. I remember 
> enjoying
> hearing even the cacophony of noise that resulted when the 
> skip would
> roll in and I'd hear (dozens of?) radio signals fading in and 
> out.

I'll second that.  My brother and I had a pair of those with a 
superregenerative detector.  If you adjusted the regen 
carefully (just before the point where it broke into 
oscillation), you could sometimes hear CBers in Louisiana and 
Alabama (due, no doubt, to the glories of the Kilowatt Linear). 
In retrospect, talking back to them on 100 mw would have been 
quite a feat, but that didn't stop us from trying ;-)

Manolis C. Tsakiris wrote:

   ...

> in DVDs the audio signals are modulated digital pulses (and not analog
> waveforms), such as PCM, and their spectrum is no longer that of an
> acoustical signal (20Hz-20kHz), justifying the need for a higher sampling
> rate.

That sounds like doubletalk to me. Would you please rephrase it in 
simpler terms? A few therefores and becauses would help.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������

rickman wrote:

   ...

> You can poo-poo this sort of evaluation.  But that doesn't make you
> right.  Do you have any "proof" that no one can hear the difference?
> Do you even know what the differences are that I was talking about?

What is your opinion of the benefit of using 0-0 gauge gold-plated Litz 
wire or flat braid for speaker cables? How about CD demagnetizers? There 
are many listeners' claims for theose also.

   ...

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������

robert bristow-johnson wrote:

   ...

> now, in *processing* sounds with some nasty non-linearities in the
> process, it very well may be necessary to upsample to 192 kHz or
> higher to do that non-linear processing, and when it is done, LPF to
> 20 kHz and downsample back to 48 kHz.  but, except for experimental
> purposes, 192 kHz storage or transimssion is not necessary.

You're wearing an engineer's hat. Now try to think like a marketeer. :-)

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������