http://www.asa.org.uk/ASA-action/Adj.../Russ-Andrews-
Accessories-Ltd/TF_ADJ_49597.aspx
--
Tony Sayer

In article ,
tony sayer wrote:

http://www.asa.org.uk/ASA-action/Adj.../Russ-Andrews-
Accessories-Ltd/TF_ADJ_49597.aspx

FWIW I noticed a while ago that Russ was appealing against the ASA decision
and had commissioned a 'paper' to give him a basis. I then read that and
wrote http://www.audiomisc.co.uk/cables/ma...ingTheory.html as a
result. That page is followed by a couple of others that explain more
'normal' types of filters.

No idea if the ASA have seen the above page, though, nor who their 'expert'
was or if that person saw it.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

"tony sayer" wrote in message
...

http://www.asa.org.uk/ASA-action/Adj.../Russ-Andrews-
Accessories-Ltd/TF_ADJ_49597.aspx
--
Tony Sayer

I love the defence that all this stuff is subjective, and it can't be
measured so it doesn't matter if it's not real, as long as buyers (who are
all informed enthusiasts) believe it......

Bit like Homeopathy really.

S.

"tony sayer" wrote in message
...

http://www.asa.org.uk/ASA-action/Adj.../Russ-Andrews-
Accessories-Ltd/TF_ADJ_49597.aspx
--
Tony Sayer




Curiously, in the feb issue of HFW it's editor has dedicated his
opinion column on page 89 to the very subject of perceived
differences/improvements in cables etc, but no reference to
any ASA ruling?

Capacitance? Inductance, we do the hokey kokey and we turn
about, thats what it's all about?
I stick to the PMi law, if we can hear it then it's measureable,
and if it's measureable then it will be subjectively discernable!

In article , Serge Auckland
wrote:

"tony sayer" wrote in message
...

http://www.asa.org.uk/ASA-action/Adj.../Russ-Andrews-
Accessories-Ltd/TF_ADJ_49597.aspx -- Tony Sayer

I love the defence that all this stuff is subjective, and it can't be
measured so it doesn't matter if it's not real, as long as buyers (who
are all informed enthusiasts) believe it......

Yet RA got Ben Duncan to do measurements to try and support his claims...

Given the current state of English Libel Laws I won't state my full views
on the resulting report. I'll leave others to form their own views. :-)

....although that said, I guess I can point out

http://www.audiomisc.co.uk/Electroni...eshift/cp.html

which deals with the results published some years before from measurements
I assume were made by Ben Duncan where he discovered another cable 'effect'
new to science. However so far as I could see, the results can be explained
nicely as simply due to a change in a component value in the test system
during the measurements. :-)

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article , Fed Up Lurker
wrote:

"tony sayer" wrote in message
...

http://www.asa.org.uk/ASA-action/Adj.../Russ-Andrews-
Accessories-Ltd/TF_ADJ_49597.aspx -- Tony Sayer


Curiously, in the feb issue of HFW it's editor has dedicated his opinion
column on page 89 to the very subject of perceived
differences/improvements in cables etc, but no reference to any ASA
ruling?

What is the date of the ruling? Bending over backwards to be fair to HFW,
it may be because their production cycle is a few months, so the issue was
set before the ruling became public.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

"Fed Up Lurker" wrote

But if it is subjectively
discernable then in this day and age it is measurable.

Gosh, something from "Fed Up Lurker" (an entirely inappropriate user name if
ever there was one) that I can agree with!

It's hard to decipher your long, rambling post, but you appear to be
claiming that there is a measurable and audible difference between different
SPDIF interconnects that isn't simply a matter of bit errors. SPDIF merely
transmits a series of numbers, and as long as those numbers arrive at the
far end unaltered then the transmission is perfect and there *cannot* be any
differences between different interconnects. There's nothing subjective
about numbers!

I've recently been experimenting with long distance transmission of SPDIF
over Cat5 cable using RS422 driver and receiver chips. I've been able to
send error-free SPDIF over 200m of this stuff and, as expected, there is
absolutely no subjective difference whether the source player and DAC are
directly connected via TOSLINK, or the signal is diverted via 200m of Cat5.

David.

In article , David Looser
wrote:
"Fed Up Lurker" wrote

But if it is subjectively discernable then in this day and age it is
measurable.

Gosh, something from "Fed Up Lurker" (an entirely inappropriate user
name if ever there was one) that I can agree with!

It's hard to decipher your long, rambling post, but you appear to be
claiming that there is a measurable and audible difference between
different SPDIF interconnects that isn't simply a matter of bit errors.
SPDIF merely transmits a series of numbers, and as long as those
numbers arrive at the far end unaltered then the transmission is
perfect and there *cannot* be any differences between different
interconnects. There's nothing subjective about numbers!

Indeed. That is why Paul Miller and others can routinely show that the
effects of jitter on the analogue output from the dac can measurably vary
when you do something like change the connecting cable. (Plus due sometimes
to other causes like a computer not sending the data in a regularly timed
manner.)

So in *measureable* terms there is more to this than simply ensuring 'bit
perfect' sequences of values. They also then have to be converted by the
dac. This means the system has to also cope with the 'serial stream' format
employed. 'Bit perfect' is a necessary-but-not-sufficient condition. Other
aspects have to be adequate as well.

That said, my own view is that it should really be the responsibility of
the dac/receiver to prevent such cable/signal transfer imperfections from
exhibiting jitter effects in the analogue output. And I can't say that I've
personally really noticed such effects when listening to the music. And
I've cheerfully used runs of 50 Ohm co-ax and home made switch boxes that I
made not attempt to ensure had a characteristic impedance near 75 Ohms,
etc. :-)

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Fri, 14 Jan 2011 09:17:44 +0000 (GMT), Jim Lesurf
wrote:

In article , David Looser
wrote:
"Fed Up Lurker" wrote

But if it is subjectively discernable then in this day and age it is
measurable.

Gosh, something from "Fed Up Lurker" (an entirely inappropriate user
name if ever there was one) that I can agree with!

It's hard to decipher your long, rambling post, but you appear to be
claiming that there is a measurable and audible difference between
different SPDIF interconnects that isn't simply a matter of bit errors.
SPDIF merely transmits a series of numbers, and as long as those
numbers arrive at the far end unaltered then the transmission is
perfect and there *cannot* be any differences between different
interconnects. There's nothing subjective about numbers!

Indeed. That is why Paul Miller and others can routinely show that the
effects of jitter on the analogue output from the dac can measurably vary
when you do something like change the connecting cable. (Plus due sometimes
to other causes like a computer not sending the data in a regularly timed
manner.)

So in *measureable* terms there is more to this than simply ensuring 'bit
perfect' sequences of values. They also then have to be converted by the
dac. This means the system has to also cope with the 'serial stream' format
employed. 'Bit perfect' is a necessary-but-not-sufficient condition. Other
aspects have to be adequate as well.

That said, my own view is that it should really be the responsibility of
the dac/receiver to prevent such cable/signal transfer imperfections from
exhibiting jitter effects in the analogue output. And I can't say that I've
personally really noticed such effects when listening to the music. And
I've cheerfully used runs of 50 Ohm co-ax and home made switch boxes that I
made not attempt to ensure had a characteristic impedance near 75 Ohms,
etc. :-)

Slainte,

Jim

As you say. If one simply uses the incoming data stream as the DAC
clock, just reading in the words as they arrive, then any jitter is
transferred directly to the audio output and will be more or less
audible.

The right way to do it (although it probably costs 50p more) is to
buffer the input data and lock a slow synth to it to generate the
clock. That will give audibly perfect output up to the point where the
digits are actually coming in wrong.

And of course the term jitter is used with cables - wrongly in my
view. Jitter is a random perturbation of the data edges caused by
noise events. The inaccuracies caused by cables are systematic and
identical on each data edge. This means that they can be corrected.
Either matching the cable better or using channel estimation (all
mobile phones have this and it is dirt cheap) to measure and cancel
the inaccuracies that shift the edges out of place.

So what I am saying is that there is no longer any excuse for a
digital cable's properties to be an audible component of any hi fi
system

d

"Don Pearce" wrote in message


And of course the term jitter is used with cables -
wrongly in my view. Jitter is a random perturbation of
the data edges caused by noise events. The inaccuracies
caused by cables are systematic and identical on each
data edge. This means that they can be corrected. Either
matching the cable better or using channel estimation
(all mobile phones have this and it is dirt cheap) to
measure and cancel the inaccuracies that shift the edges
out of place.

The digital signal's edges tend to wander around because the cable is
ultimately a low pass filter and the spectral content of the digital data
passing through the cable varies as the data varies. So matching the cable
better can't be of much help.

That leaves the more complex methods like channel estimation or buffering
and reclocking.