"Jim Lesurf" wrote in message
...
In article , Keith G
wrote:

"Serge Auckland" wrote in message
...
Keith G wrote:

I think the nub of your response is that people "believe" things sound
different. It's the same mental process that have people believing in
God, the Tooth Fairy and Santa Claus. They don't have a shred of
objective evidence that things sound different, just their faith.


Let's say they *perceive* things to sound different.

OTOH lets *not* say they "perceive" things since that then opens up all
the
ambiguities and misundestandings where people use the word 'perceive' in
different ways and argue at cross-purposes... :-)



What word would you prefer then? They have to perceive to believe, do they
not?

(Reminds me of a Moody Blues track!! :-)

"Nick Gorham" wrote in message

Arny Krueger wrote:
"Nick Gorham" wrote in message


Serge Auckland wrote:

Ian Iveson wrote:


The DSP solution would appear to be preferable.
However, presumably there are rounding errors. That
is, if I divide every word by a constant, each result
must be rounded to the nearest step, and this
rounding error is not linear wrt the audio signal. I
assume there is a name for this kind of error? How
significant is it?


The DSP solutions I'm familiar with operate either
floating point or 32 or 48 bit internal which means
that when the output is finally reduced to 16 or 24 bit the
errors from the DSP calculations are
minimised. I don't know of a specific name for the
errors resulting from DSP operation.


But even if the internal calculation is done with larger
resolution, you still loose one bit of output resolution
for every 6db of attenuation.


A very similar thing happens with analog level controls.
In the real world, even more so.

Yes, I guess so by definition, but I would hope a quality
pot or stepped attenuator should start with more than
96db worth of resolution.

You seem to forget that pots and stepped attenuators are generally attached
to power amps and preamps. Power amps can have from 80 to 115 dB dynamic
range , butwith consumer amps crowded more toward the lower end of the
range. Most home audio preamps have only 70 to 90 dB dynamic range,
depdening on the input.

"Serge Auckland" wrote in
message
Nick Gorham wrote:
Serge Auckland wrote:

I think the nub of your response is that people
"believe" things sound different. It's the same mental
process that have people believing in God, the Tooth
Fairy and Santa Claus. They don't have a shred of
objective evidence that things sound different, just
their faith. I'll accept that pots, capacitors, resistors etc. sound
different when I see objective measurements that
indicate that there should be a difference and the
results of properly conducted double-blind tests that
show that there was a difference. S.
S.

http://members.aol.com/sbench102/caps.html

Interesting. I'll study it in the next day or two.

It's not what it seems. The testing procedures ignored the nonlinearity of
an audio transformer, and did not use the caps as they are typically used in
audio gear.

"Jim Lesurf" wrote in message
...
In article , Keith G
wrote:

"Jim Lesurf" wrote in message
...



I don't buy extra warranty

Nor do as it is generally an over-priced con.

- who TH wants 'electronics' to last 3 years these days?

I do. :-) Although it depends on the nature of the item in question.
e.g.
I would not expect a compact fluro lamp to last forever. However if I buy
something like an amplifier or loudspeakers I'd want them to work
correctly
for some decades.


OK, as you say, it depends on the nature of the item - there are plenty of
gadgets that have become superceded (specs., design, speed, capacity &c.) by
the time the manufacturer's warranty has run out. I understand that Sony's
policy was to 'make their own products obsolete before the competition
did'...!!??

On Wed, 24 May 2006 13:10:40 +0100, Nick Gorham
wrote:

Jim Lesurf wrote:
In article , Nick Gorham
wrote:

Serge Auckland wrote:


I'll accept that pots, capacitors, resistors etc. sound different when
I see objective measurements that indicate that there should be a
difference and the results of properly conducted double-blind tests
that show that there was a difference.



http://members.aol.com/sbench102/caps.html


I've only had a quick look at the above, and the pages linked to it.
However they don't seem to me to be particularly relevant to the question
of capacitors normally having a 'sound' in normal use.

The first thing that struck me about the page was the following which I
quote:

"The signal level was held constant at about 70 volts RMS at 600 Hz across
the capacitors. (for about 26mA signal current). This is probably more
than you would normally expect,..."

My reaction to the last phrase was,,, "indeed!" :-)

I can't recall ever building or using an audio amplifier or tuner that had
anything like this large an *audio voltage* across any of the *capacitors*.
Note the above is 70v RMS *between the capacitor terminals*. i.e. not just
an input where most of the voltage appears elsewhere. I have certainly
built (and use!) amps which have audio voltages this large inside them, but
not between the terminals of any of the signal capacitors.


The fact you may not have built such a thing, doesn't mean they do not
exist. Using a coupling cap between a driver and the grid of a 211 would
have this sort of voltage, as will most driver valves. a 845 would have
a much higher voltage.

A even more extreme example could be a cap used in a parallel feed
output stage, that could have 1kv or more across it.

You appear to be confusing DC conditions with signal voltage.

d

--
Pearce Consulting
http://www.pearce.uk.com

"Jim Lesurf" wrote

I also have never found anyone who was able to hear any difference between
one pot or attenuator or another solely on the basis of the sounds
produced
- provided the pots were used appropriately and we make an exception for
variations in balance tracking.


The only differences I've ever heard between pots is noise when they need
cleaning/replacing. What is annoying is that the 'volume' cen come through
erratically (loud/soft/loud) in an unpredictable way when they start to play
up - I've got a radio that is doing this right now.




Interesting that you are never challenged here, Serge. You wouldn't have
to wander far from this group to find a lot people who quite strongly
believe that all components (resistors, caps, pots &c.) can influence
the sound from audio kit.

You could probably say something similar about flying saucers, or various
belief systems...


Sure and there are those who believe the fridge light *really* does go out
when you shut the door!! :-)

(Incidentally, why bother with a switch on fridges? Could anybody say
*categorically* that saves energy/extends bulb life rather than just having
it stay on all the time, especially when the cost of the parts, the
manufacture thereof and fitting the switches is taken into account?)



I have no real knowledge and very little experience, so no strong views
- I always say I think it's possible (even likely) different components
will 'sound different', but is it really *hearable*...???

Can only say that this was one of the areas I tested (repeatedly) when
working on amplifiers, etc. Did this using listening tests on people in
the
audio biz. None were ever able to tell one pot from another by 'sound'.
What would show were tracking variations, or defects like scraping noises
for pots that were badly made or had deteriorated. Or in some cases, RC
roll off effects if the RC effect was unusually bad. Could not find any
signs of anyone who could tell a fancy/expensive pot from a cheap one by
'sound'.


Yet they are manufactured, bought and used - in considerable numbers....???

(See my recent reply to Pinky about cheap pots 'letting go'!!)

The sun's just come out (!!) and I got stuff to do, so I'll just say that
without all this *belief*, *perception*, *self-delusion* &c,, there would be
little point in trying to reproduce music in the home with anything but real
players (heard that phrase somewhere before!) and real intruments - and
absolutely no point whatsoever in watching a movie - war films, westerns and
sci-fi being perhaps the best examples!!

Jim Lesurf wrote:
In article , Nick Gorham
wrote:

Serge Auckland wrote:


I'll accept that pots, capacitors, resistors etc. sound different when
I see objective measurements that indicate that there should be a
difference and the results of properly conducted double-blind tests
that show that there was a difference.



http://members.aol.com/sbench102/caps.html


I've only had a quick look at the above, and the pages linked to it.
However they don't seem to me to be particularly relevant to the question
of capacitors normally having a 'sound' in normal use.

The first thing that struck me about the page was the following which I
quote:

"The signal level was held constant at about 70 volts RMS at 600 Hz across
the capacitors. (for about 26mA signal current). This is probably more
than you would normally expect,..."

My reaction to the last phrase was,,, "indeed!" :-)

I can't recall ever building or using an audio amplifier or tuner that had
anything like this large an *audio voltage* across any of the *capacitors*.
Note the above is 70v RMS *between the capacitor terminals*. i.e. not just
an input where most of the voltage appears elsewhere. I have certainly
built (and use!) amps which have audio voltages this large inside them, but
not between the terminals of any of the signal capacitors.


The fact you may not have built such a thing, doesn't mean they do not
exist. Using a coupling cap between a driver and the grid of a 211 would
have this sort of voltage, as will most driver valves. a 845 would have
a much higher voltage.

A even more extreme example could be a cap used in a parallel feed
output stage, that could have 1kv or more across it.

--
Nick

Jim Lesurf wrote:
In article , Nick Gorham
wrote:

Arny Krueger wrote:

"Nick Gorham" wrote in message


A very similar thing happens with analog level controls. In the real
world, even more so.




Yes, I guess so by definition, but I would hope a quality pot or stepped
attenuator should start with more than 96db worth of resolution.


What are you defining as "resolution" in the above?


Even Arny knew what I meant.

I was agreeing with the point Arny made BTW.

--
Nick

Jim Lesurf wrote:
In article , Nick Gorham
wrote:

Serge Auckland wrote:


I'll accept that pots, capacitors, resistors etc. sound different when
I see objective measurements that indicate that there should be a
difference and the results of properly conducted double-blind tests
that show that there was a difference.



http://members.aol.com/sbench102/caps.html


I've only had a quick look at the above, and the pages linked to it.
However they don't seem to me to be particularly relevant to the question
of capacitors normally having a 'sound' in normal use.

I was trying to provide information relating to the "I see objective
measurements that indicate that there should be a difference" part, not
the "sound" as such.

--
Nick

Don Pearce wrote:
On Wed, 24 May 2006 13:10:40 +0100, Nick Gorham
wrote:


Jim Lesurf wrote:

In article , Nick Gorham
wrote:


Serge Auckland wrote:


I'll accept that pots, capacitors, resistors etc. sound different when
I see objective measurements that indicate that there should be a
difference and the results of properly conducted double-blind tests
that show that there was a difference.



http://members.aol.com/sbench102/caps.html


I've only had a quick look at the above, and the pages linked to it.
However they don't seem to me to be particularly relevant to the question
of capacitors normally having a 'sound' in normal use.

The first thing that struck me about the page was the following which I
quote:

"The signal level was held constant at about 70 volts RMS at 600 Hz across
the capacitors. (for about 26mA signal current). This is probably more
than you would normally expect,..."

My reaction to the last phrase was,,, "indeed!" :-)

I can't recall ever building or using an audio amplifier or tuner that had
anything like this large an *audio voltage* across any of the *capacitors*.
Note the above is 70v RMS *between the capacitor terminals*. i.e. not just
an input where most of the voltage appears elsewhere. I have certainly
built (and use!) amps which have audio voltages this large inside them, but
not between the terminals of any of the signal capacitors.


The fact you may not have built such a thing, doesn't mean they do not
exist. Using a coupling cap between a driver and the grid of a 211 would
have this sort of voltage, as will most driver valves. a 845 would have
a much higher voltage.

A even more extreme example could be a cap used in a parallel feed
output stage, that could have 1kv or more across it.


You appear to be confusing DC conditions with signal voltage.

d


Maybe, ok, in both cases there will be a DC voltage, but there will also
be the signal voltage of the magnitude we are talking about.

--
Nick