Re: I Call For A Lynching


"Sander deWaal" <nospam@xxxxxxxxxx> wrote in message
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"ScottW" <ScottW48@xxxxxxxxxxx> said:


<vinylanach@xxxxxxx> wrote in message
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Of course. With the Shunyata power conditioner and power cords in
place, some of the hum and noise I experienced with a low-powered SET
and high-efficiency speakers completely disappeared.


All that tells me is that your SET power supply implementation is
flawed. I wonder if the Shunyata includes an isolation
transformer. That could explain some of your experience.
Of course isolation transformers aren't particuluarly expensive,
especially one for a low powered set.
Did you open the stardust box and see what magic was
inside?


An isolation transformer lets both mains leads "float" respecive to
ground (or neutral) , which could be an improvement in case of ground
loops via interconnects (in case of potential differences between
grounds of components).

In some cases, problems may arise when one apparatus is grounded and
the other is not.

From the description, I don't think there's an isolation transformer
inside the Shunyata.
It is well known that some materials can absorb RF energy, such as the
anti-static carbon mats used for transporting semiconductors.

We use 'em all the time in. Our anechoic chamber for EMI is lined with
36" deep cones of the stuff. We use it in environmental chambers
when needing to radiate GPS signal into the chamber and cut down
reflections.

The idea the radiated reflections can get back inside the unit and cause
problems (or even conducted reflections) ignores the fact that the reflection
amplitudes will be a fraction of the original noise which may cause problems.


How this may be of influence on a 50/60 Hz power supply is beyond my
knowledge, however.

Considering the amplitude of the noise and the amount of filtering
the power should go through...its very hard to imagine.

I think they're just piggybacking a bit on claims like DVDs where the
video circuits can be disabled to lower the noise level in the audio
sections. Even this is a bit of a stretch, but doing something outside
the unit and making a similar claim has no sound technical basis IMO.



There's a lot of stuff on the market that
simply doesn't work. But there are power accessories that do work,
especially if you have a highly-resolving system.


Or you have components with substandard power supplies designed in.
A very big functional part of every active device, pre-amp, power amp,
CD is to condition its AC power source to be suitable for use
to its circuits. Virtually none of these circuits can be powered
directly by 120 VAC. They all required built in power
conditioners and converters to work at all. If yours needs external
help, that isn't much of an appraisal.


As an electronic engineer, and with the knowledge I possess now,
I tend to think that stuff like this can't work like they claim it
does..
And yet, even I do use different types of capacitors and cables in my
system that seem to sound different.

As far as caps go, there are sound reasons why caps in the signal
path sound different.

Check this article from Agilent
http://www.mobilehandsetdesignline.com/howto/192300586

There are a few snips which can clearly show why different
caps may sound ...different.

Film capacitors, such as those with polyester and
polypropylene dielectrics, have low-enough loss terms
that this time-domain technique can give results that are
accurate to 1%. The errors introduced by non-film dielectrics,
however, do not necessarily demand the use of a high-performance LCR meter.

or

For an aluminum electrolytic capacitor, the capacitance can
vary as much as a few percent between frequencies of 100 Hz and 1 kHz.

or

This DC bias term does not create significant errors for film and
ceramic capacitors; however, for aluminum-electrolytic capacitors,
it can have a large impact on the result. This is due to the property
that the ESR changes nonlinearly with DC bias.

In a past life I worked in a component engineering group
for a mainframe and military computer manufacturer.
We did lots of discrete component characterization
with the best equipment available at the time and it
was clear that cap data sheets don't always tell the whole
story. Lots of parameters vary with freq, DC bias, and
polarity. Characterizing all the cap parameters across
these 3 dimensions is arduous.
There are sound technical reasons why different caps
may alter FR and introduce non-linearity's to an amp
and therefore sound different.



Next month, I'm about to do a double blind test on several components
(capacitors and cables) to see if what I think I hear, really is due
to audible differences.
Candidates: Clarity Cap SA:
http://www.claritycap.co.uk/ and

John Van Gent cables :
http://www.johnvangent-audiokabels.nl/nl/ned_inleiding.html

The test will be proctored by Jacco Dekkers from NXP (former Philips
Nat Lab).

Cool, I look forward to your results.
In the cable tests, I hope you'll use multiple sources and loads.
IMO, well designed SS gear should be immune to load variance
due to cables while some high output impedance
gear may be impacted.

ScottW


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