Blind Listening Tests & Amplifiers

[fdegrove]

Hi,

Remember, I said with the same LCR properties.

No offense, but are all Ls, Cs and Rs created equal?

They still measure the same if measured only for that particular parameter, don't they?

All this somehow reminds of the old engineering adagio that said :

A resistor is a resistor is a resistor...

I would certainly hope we know better than that by now?

You guys on the other hand are trying to hear a difference, so your results would be more credible than mine.

I don't think so, whatever way you're biased the audible differences are so obvious, they're really hard to ignore.

Oh, I don't have any trouble at all designing cables that have the same measured L,R and C values and would still sound totally different from one another...easy.

Cheers,

[Pan]

Zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz hrrrm!

Why is it so fxxxing hard for some people to realise that cables have their own sounds, I´m getting sooo tired of this closed minded people.

Me and a friend set out to do a BLT to convince him that I easily could tell the cables apart and also to report back to a thick-headed non-believer on another board.

Because of the way my system is set up we decided to do a quick switch back and forth just to get the initial feel for the difference. As I experienced so many times before, the difference we both heard was so obvious it was totally silly to go ahead and waste time in a blind test.

Get this into your head non-believers, audiocables such as IC´s and speakercables have their own unicque (how about that spelling ) sound which makes it worthwhile to experiment with different cables if you want to draw the last bit of performance out of your rig. This is true even for short lengths of 0.5-1 meter or even shorter.

/Peter

[Steve Eddy]

Originally posted by Pan
Why is it so fxxxing hard for some people to realise that cables have their own sounds, I´m getting sooo tired of this closed minded people.

And how open-minded is it for one to be in complete denial of the very real psychological aspects which have been shown over and over again to cause differences to be perceived even when none exist? I don't know about you but this seems rather closed-minded to me.

Me and a friend set out to do a BLT to convince him that I easily could tell the cables apart and also to report back to a thick-headed non-believer on another board.

Because of the way my system is set up we decided to do a quick switch back and forth just to get the initial feel for the difference. As I experienced so many times before, the difference we both heard was so obvious it was totally silly to go ahead and waste time in a blind test.

Yet those just as confident as you and your friend, when tested under blind conditions, have done no better than if they were simply guessing.

Similarly, others are just as confident that placing photographs of themselves in their freezers also produces differences as obvious as those you claim here.

Talk is cheap. There has been literally DECADES of talk along these lines. When is someone finally going to stop flapping their gums and step up to the plate and just prove it once and for all so we can put an end to this debate and move on to something more productive? Why are we still here some 30 years hence arguing about it if it's as obvious as you say? It should have been put to rest long ago.

Get this into your head non-believers, audiocables such as IC´s and speakercables have their own unicque (how about that spelling ) sound which makes it worthwhile to experiment with different cables if you want to draw the last bit of performance out of your rig. This is true even for short lengths of 0.5-1 meter or even shorter.

Once again, talk is cheap. Your claims have no more validity than those of the "non-believers." Just another of the tens of thousands who have come before you.

Instead of just being another face in the crowd, why don't you become "the one"? Don't wait around for some bald black guy in a duster and shades to offer you some pills. You already claim to know how deep the rabbit hole goes. It would be ground-breaking.

Or are we to have yet another bacth of excuses leading to another 30 years of "Tastes great!" "Less filling!"?

And for the record (which includes a public record of posts going back 20 years), I hold no particular beliefs on this issue one way or the other. My fasciation with this issue relates to my fascination with religious fundamentalism and what causes otherwise seemingly rational people to become so frighteningly irrational.

So anyone thinking of trying to pigeonhole me into some simpleminded black and white "believer/non-believer," "yaysayer/naysayer" slot can just forget about it.

se

[mrfeedback]

An experiment that I performed 10 years ago showed me that dielectrics can make a sonic difference in an interconnect.
The IC concerned consisted of 4 solid-core wires in star quad configuration arranged around a 4mm diameter stiff plastic rod, all sourced from stripped down Apogee IC cable.
The individual wires originally were clad in teflon sleeves, which were retained in the first experiment, and the the four wires and rod wrapped with Teflon plumbers tape.
Second experiment was to swap the teflon tape for standard office cellotape.
Third experiment was to remove the teflon sleeves and re-wrap with teflon tape.
Fourth experiment was as above and cellotape wrap.
Fifth experiment was to remove all wrappings and center rod, and the wires uninsulated and air spaced.
All configurations sounded different, with the teflon causing a hardness/brightness, and the cellotape causing a different crackly brightness.
Electrically all configurations ought to have measured (I did not do so) the same because the same wires were used and with the same spacing, however all five configurations sounded significantly different to each other, and all configurations sounded wildly different to the original cable assembly.
The factor accounting for sonic differences can only be differing dielctric materials.

Eric.

[andy_c]

PMFJI, but I wanted to interject something regarding the importance of R, L, C and (it seems to have been left out in some posts) G. Some folks are apparently of the view that these parameters are some kind of lumped circuit approximation to the actual wave propagation that occurs. These parameters actually fully represent the wave propagation, and are totally consistent with Maxwell's equations for the TEM mode of propagation in a transmission line.

The important thing is, these parameters are not resistance, inductance, capacitance and conductance, but rather resistance, inductance, capacitance and conductance per unit length. This does not mean that you take these numbers, multiply them by the length of the cable and get a single resistance, inductance, capacitance and conductance value. It means that each infinitesimally short section of cable has an incremental series resistance and inductance, and an incremental shunt conductance and capacitance.

The equations representing this structure are derived by taking the limit as this incremental length approaches zero. This is illustrated here:

http://emlab2.nmsu.edu/classes/ee315/tl/node2.html

Notice that the current and voltage are expressed as a function of both position and time. The two equations that result are combined into one, as shown here:

http://emlab2.nmsu.edu/classes/ee315/tl/node3.html

The equation that results is a wave equation, not a simplified lumped circuit equivalent.

Further information can be found here:
http://www.ece.uci.edu/eceware/hspic...124.html#14853

Now R, L, C and G are in general functions of frequency, but knowing all these parameters over a broad bandwidth that includes the audio frequency range gives a very accurate representation of the wave propagation in the cable at those frequencies.

So if someone tells you that R, L, C and G don't fully describe the electrical properties of a cable, it's likely that they don't understand transmission line theory. Be aware also that Maxwell's equations, used up to hundreds of GHz, don't even attempt to describe what happens to individual electrons (that's quantum theory). Instead, they deal with continuous charge distributions rather than discrete electrons for example. Yet given the appropriate transmission line models, Maxwell's equations have been shown time and time again to yield results as close to measured data as can be physically achieved.

So if quantum theory is not necessary to accurately describe wave propagation in the millimeter wave region, it's unlikely that it should be necessary in the audio range.

So save your money! There's lots of DIY cable recipes on the net that are based on sound (no pun intended) engineering (low inductance, reduction of high-frequency losses by using multiple insulated wires of small diameter, etc.). I see no reason why these designs can't be sonically as good as any cable that could be bought, regardless of price.

[andy_c]

Originally written by mrfeedback
Electrically all configurations ought to have measured (I did not do so) the same because the same wires were used and with the same spacing, however all five configurations sounded significantly different to each other, and all configurations sounded wildly different to the original cable assembly.
The factor accounting for sonic differences can only be differing dielctric materials.

Hi Eric,
It's likely that the dielectric constants were different between the two materials (cellotape vs. teflon). The relative dielectric constant of teflon is around 2.2, but I don't know about the cellotape. I suspect it's higher. Different dielectric constants mean different capacitance per unit length. Think of the parallel plate capacitor where:

C = (epsilon * A) / d

where epsilon is the dielectric constant, A is the area, and d is the separation. If A = length * width, you can see that the capacitance per unit length is proportional to the dielectric constant. Also, it's likely that the shunt conductance loss is higher in the cellotape than the teflon. Teflon is very low loss. It's often used for circuit boards in the microwave frequency range. So what I'm saying is it's likely that the cables would have measured differently because of the different capacitance per unit length, which results from the different dielectric constants of the materials.

[Steve Eddy]

Originally posted by andy_c
So if someone tells you that R, L, C and G don't fully describe the electrical properties of a cable, it's likely that they don't understand transmission line theory.

And if someone were to say that R, L, C and G DO fully describe the electrical properties of a cable, would it be fair to say that they don't understand that R, L, C and G are idealized elements and only fully describe an idealized cable and do not fully describe realworld cables which use non-idealized conductors and dielectrics?

se

[mrfeedback]

Hi Andy,
I agree and confer with what you say here.
However in these and other experiments I have found teflon to impart a particular sonic signature, and further according to the pigments loaded into the teflon.
Sure I expect these pigments to alter the Dielectric Constant, and also the Dissipation Factor of these dielectric materials.
Is this a further cause of these sonic changes ?.

Eric.

[andy_c]

Eric,
I haven't a clue regarding the pigments and their effect (or not) on the dielectric constant and losses. I do know that there are many different variations of teflon, like this one, which is quartz-loaded:

http://www.rogers-corp.com/mwu/pdf/6002data.pdf

with a dielectric constant of 2.94, and this one:

http://www.rogers-corp.com/mwu/pdf/5000data.pdf

with a dielectric constant of 2.2. But to tell the truth, I've not seen dielectric constant measurements of the teflon insulating material used on typical hookup wire. I've just assumed (maybe incorrectly) that it's similar to the 5880 microwave laminate that isn't loaded with quartz.

It's too bad the pads lift so easily on these Rogers materials, because they are really high quality. Expensive too.

[Steve Eddy]

Originally posted by andy_c
I haven't a clue regarding the pigments and their effect (or not) on the dielectric constant and losses.

Belden had a write-up about this but I'll be damned if I can find it at the moment. I'll keep looking.

It's hardly any leap of logic given that the pigments used will have different dielectric properties than the dielectrics they're being used to color and it would be expected that the combination of the two would alter the characteristics of the primary dielectric.

se