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post #1591 of 1790
Quote:
Originally Posted by jaddie View Post

Sure, we're a bunch of crotchety skeptics.  But all we really ask is, if a product or item provides a benefit, that benefit should be clearly identifiable as a difference in a double-blind test.  If not, there's reasonable doubt that it is of any benefit.  

I couldn't agree more.

post #1592 of 1790
Quote:
Originally Posted by Greenleaf7 View Post

Not sure if anyone has seen this already, but i found it to be a rather interesting read.

 

http://www.hometheaterhifi.com/volume_11_4/feature-article-blind-test-power-cords-12-2004.html

Can't put my finger on the reference (probably from David Clark, though) but the switching time between choices is inversely proportional to the ability to detect small differences.  Less switch time, higher ability to detect small differences.  You need to keep switching time down to a few milliseconds for highest reliability in comparison, and ideally, near zero.  Their cable switch time as as much as 75 seconds, and the test was technically single-blind. But otherwise, a study in guessing.  I got a chuckle out of their aversion to "sound-compromising switching apparatus" in favor of long switch times.  Essentially, making the comparison much harder in leu of a power switch (a sound-compromising power switch). 

post #1593 of 1790
Quote:
Originally Posted by Greenleaf7 View Post

I believe what he's trying to say, in terms of a coffee mug analogy, is that your coffee will taste the same irrespective of what mug is used as long as it isn't broke. In other words, it's like saying that an "upgrade snake oil gold reference coffee mug" will not make the coffee taste any better at all.

That is baloney. A rusty, plasic, styrofoam, plain dirty and so on cup or mug will affect the taste of coffee. Do the little monkeys lack common sense ?


Edited by zorin - 5/19/13 at 3:15am
post #1594 of 1790

the analogy still works - youre referring to broken cups, and broken cables also affect sonics negatively.  no one disputes this. 

 

Quote:
Originally Posted by zorin View Post

That is baloney. A rusty, plasic, styrofoam, plain dirty and so on cup or mug will affect the taste of coffee. Do the little monkeys lack common sense ?

post #1595 of 1790

I didn't make this, though I thought it was hilarious. 

 

http://www.youtube.com/watch?v=w7Rqo8jI8dk

post #1596 of 1790
Quote:
Originally Posted by Greenleaf7 View Post

I didn't make this, though I thought it was hilarious.

It's brilliant, thanks for the link.
post #1597 of 1790

^ lmao

post #1598 of 1790

I am not fully convinced about "the sound of cables" but what cant be argued against and doesn't seem to be mentioned is that any cable carrying a very low level signal that has has a high amount of inductance/capacitance  has  been proved scientifically to effect the frequency response of the signal . This isn't "pie in the sky" but completely proven with test equipment and the higher the frequency the higher the change. One of those cables looking into a sensitive amp will be seen as a "tuned circuit" that's why many old tube amps with a high input impedance  picked up radio signals till stubber caps were fitted.

post #1599 of 1790

These interconnects are a few inches long and connect the source with an impedance of ~100 ohms with the amp's input with an impedance of ~10 kOhms... How much capacitance would it take to get an audible roll-off?

post #1600 of 1790
Quote:
Originally Posted by duncan1 View Post

I am not fully convinced about "the sound of cables" but what cant be argued against and doesn't seem to be mentioned is that any cable carrying a very low level signal that has has a high amount of inductance/capacitance  has  been proved scientifically to effect the frequency response of the signal .

 

The level of the signal is irrelevant. And you'd have to pretty much go out of your way to design a cable with enough inductance or capacitance to result in any meaningful rolloff of high frequencies. Either that or be using unusually long lengths of cable.

 

se

post #1601 of 1790
Quote:
Originally Posted by duncan1 View Post

 One of those cables looking into a sensitive amp will be seen as a "tuned circuit" that's why many old tube amps with a high input impedance  picked up radio signals till stubber caps were fitted.

The RFI problem was that the cable acts as an antenna, and the first stage acts as a detector. No tuned circuit necessary for that to happen, and just some RF proofing right at the input jack solves the problem.  It would happen with any cable regardless of C, I or R. 

post #1602 of 1790

The level of signal is  irrelevant ? The most sensitive part of an audio system is the preamp I have built plenty. A high inductance/ capacitance has a direct effect on a very small signal like the input for a MC cart Do you not know 2 wires twisted together constitute a value of capacitance. Like a Hallicrafters SX28 I repaired which had 2 wires twisted together to INDUCE a transfer/ injection of a BFO signal to the local oscillator or is that great company Hallicrafters wrong too? In the 1980s I built John Lindsay Hoods -shunt feedback preamp as the signals were so low I noticed just moving the PS wires changed the induced noise so I ran the preamp wires using co-axial cable the outer sheath earthed to the star earth cured the problem I wrote the same to EW/WW at the time and had it printed in their letters page. Comments were --Good idea-never thought of it many now use that method to supply the power.to sensitive circuits.

post #1603 of 1790
Quote:
Originally Posted by duncan1 View Post

The level of signal is  irrelevant ? The most sensitive part of an audio system is the preamp I have built plenty. A high inductance/ capacitance has a direct effect on a very small signal like the input for a MC cart Do you not know 2 wires twisted together constitute a value of capacitance. Like a Hallicrafters SX28 I repaired which had 2 wires twisted together to INDUCE a transfer/ injection of a BFO signal to the local oscillator or is that great company Hallicrafters wrong too? In the 1980s I built John Lindsay Hoods -shunt feedback preamp as the signals were so low I noticed just moving the PS wires changed the induced noise so I ran the preamp wires using co-axial cable the outer sheath earthed to the star earth cured the problem I wrote the same to EW/WW at the time and had it printed in their letters page. Comments were --Good idea-never thought of it many now use that method to supply the power.to sensitive circuits.

Signal level is obviously relevant to the result in some cases, irrelevant in others, but not specifically relevant to the mechanism itself.  In phono preamps the cable C does have an impact because we're often dealing with a MM cartridge that works into a 47K resistive load. Some cartridges didn't handle extra C very well, but the last time I looked, most modern MM cartridges are fairly insensitive to capacitive loading.  In the case of MC cartridges, they are usually a very low source impedance device requiring much higher voltage gain than MM carts.  But that also means they are less sensitive to  cable C.  

 

Let's not get all wound up in IF cable C exists or in general IF it's a problem.  Each application is different, and in some cases cable C is an issue, in others it's not.  It's a question of degree and the surrounding circuit.  Examples of stray inductive or capacitive coupling causing problems aren't really helpful in the discussion, though they were no doubt real in the specific instance.

post #1604 of 1790
Quote:
Originally Posted by duncan1 View Post

The level of signal is  irrelevant ?

 

Yes.

 

Quote:
The most sensitive part of an audio system is the preamp I have built plenty.

 

Great.

 

Quote:
A high inductance/ capacitance has a direct effect on a very small signal like the input for a MC cart

 

Hasn't anything to do with the level of the signal.

 

Quote:
Do you not know 2 wires twisted together constitute a value of capacitance.

 

Yes, I do.

 

Do you know that that value of capacitance doesn't give a rat's sphincter about the signal level?

 

Quote:
Like a Hallicrafters SX28 I repaired which had 2 wires twisted together to INDUCE a transfer/ injection of a BFO signal to the local oscillator or is that great company Hallicrafters wrong too?

 

What has that to do with what we're discussing?

 

Quote:
In the 1980s I built John Lindsay Hoods -shunt feedback preamp as the signals were so low I noticed just moving the PS wires changed the induced noise so I ran the preamp wires using co-axial cable the outer sheath earthed to the star earth cured the problem I wrote the same to EW/WW at the time and had it printed in their letters page. Comments were --Good idea-never thought of it many now use that method to supply the power.to sensitive circuits.

 

Great. But again, what has that to do with what we're discussing?

 

The cutoff of a low-pass filter doesn't care about signal level. It cares about source and load impedances as they relate to the resistance, inductance and capacitance of the cable, but not signal level.

 

You should brush up on some basic electronics sometime.

 

se

post #1605 of 1790

It sounds like you are "splitting hairs"-okay in some not in others" that's so general even I cant criticize it. I stated a specific example that was correct not just in my eyes but a large US communication company  Why do you  think [as I posted elsewhere] That manufacturers to save money on design and hardware fit fuses to the internals of audio equipment instead of a stabilized PS  and at the output of the amp  a fuse that heats up and cools down creating harmonics that can be seen on a spectrum  analyzer. and so degrades the fidelity of the reproduced music.? so they make low sensitivity amps so that noise is so far down it  isnt  heard  thats taking the easy option. In the equipment I have repaired very small amounts of noise can be heard due to the  openness     of the circuit.[no filters/ comp caps/ tone controls etc]  That you are not going to hear  in nicely rounded tube technology and no I am not criticisng tubes I have built plenty  of tube amps  in the past to me they are relatively easy to work on But  you have to admit SS can go down to a very low level of detail thats why they are heavily criticised  because minute amounts of distortion can be heard.if the circuit isnt of the very top quality >In the past SS amps were dumbed down to sound like tube technology but they could never compete in the same level.

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