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10 Biggest Lies in Audio (accidental repost - sorry!) - Page 4

post #46 of 60
Quote:
Originally Posted by fiver View Post


 

Quote:
Originally Posted by Uncle Erik View Post

One, tube gear is much simpler to maintain. You can get tubes for most things and should be able to into the forseeable future. Chips, not so much. When chips go out of production, they're almost impossible to replace. Practically speaking, tubes are better. Easier to work on and you can usually find replacements. If you're in for the long haul, tubes are the safer purchase.
 


How many times have you had to replace a "chip" in a solid state amp due to failure?

 

 


There are some very highly regarded vintage amps that are unrepairable, such as the Yamaha B2

post #47 of 60
Quote:
Originally Posted by aleki View Post

lol, the author just did a self-pwn:


The simple truth is that resistance,

inductance, and capacitance (R, L, and

C) are the only cable parameters that

affect performance in the range below

radio frequencies


perhaps there wont be a drastic change in sound (I havent tried different cables, so I cant comment), but they certainly have an effect. example: my computer emits quite a bit of line noise which is glazed over every song when played at lower volumes(like I usually do). If I dont have a line attenuator hooked up, the noise becomes very noticable, specially for the drivers which are easier to drive (my friends senn IE8 is a prime example).

here's a good article about cables having an effect on the sound(perhaps they were more clean?). while it was a subtle difference, the bottom line is: there is an observable difference


Your computer emits "line noise" and and you just know that better speaker wired could cure it, even though you haven't actually tried any?

 

As for that article, it's funny. The author laments that Pear Audio backed out on an ABX of their performance claims vs. a standard set of Monster cables, because it "makes it look like Pear isn't confident that its cables would prevail, even with an experienced listener like Fremer." So instead, the author links to a second article that details results of "a similar but undoubtedly less rigorous test" that purports to show that it is possible to distinguish between high-end audio cables and regular "hardware store" grade audio cables. This test had a sample size of 39 people, of which 24 picked the "right" cable and 15 picked the wrong cable. Just off the bat, assuming a perfect experiment, there is a 10% chance of achieving these results just by guessing. Those odds aren't bad, but I'm not sure I'd base a $5000.00 purchasing decision on them. More significantly, they compare lightly shielded standard grade cable against heavily shielded $2000.00 audiophile grade cable. A more interesting (and relevant) comparison would pit a decently sheilded $100.00 cable against a $5000.00 "audiophile grade" cable. If listeners are actually perceiving a difference, IMHO, it's likely a result of EMI that would simply not be an issue with decent shielding.


 

post #48 of 60


 

Quote:
Originally Posted by scompton View Post



Quote:
Originally Posted by fiver View Post


 

Quote:
Originally Posted by Uncle Erik View Post

One, tube gear is much simpler to maintain. You can get tubes for most things and should be able to into the forseeable future. Chips, not so much. When chips go out of production, they're almost impossible to replace. Practically speaking, tubes are better. Easier to work on and you can usually find replacements. If you're in for the long haul, tubes are the safer purchase.
 


How many times have you had to replace a "chip" in a solid state amp due to failure?

 

 


There are some very highly regarded vintage amps that are unrepairable, such as the Yamaha B2


 

Yes, it's true that you cannot buy replacement power JFETS for an esoteric design that was abandoned 30 years ago.

 

If you run esoteric tube amps using designs that were abandoned 30 years ago, I suppose you may possibly have a better chance of repair.

post #49 of 60
Quote:
Originally Posted by fiver View Post


 

If you run esoteric tube amps using designs that were abandoned 30 years ago, I suppose you may possibly have a better chance of repair.



 Assuming, of course, it's the tube that died, and not some other hard to find component (not that big an assumption, actually, given the reiability of vacuum tubes vs. solid state components).

post #50 of 60


 

Quote:
Originally Posted by dsf3g View Post


..........

As for that article, it's funny. The author laments that Pear Audio backed out on an ABX of their performance claims vs. a standard set of Monster cables, because it "makes it look like Pear isn't confident that its cables would prevail, even with an experienced listener like Fremer." So instead, the author links to a second article that details results of "a similar but undoubtedly less rigorous test" that purports to show that it is possible to distinguish between high-end audio cables and regular "hardware store" grade audio cables. This test had a sample size of 39 people, of which 24 picked the "right" cable and 15 picked the wrong cable. Just off the bat, assuming a perfect experiment, there is a 10% chance of achieving these results just by guessing. Those odds aren't bad, but I'm not sure I'd base a $5000.00 purchasing decision on them. More significantly, they compare lightly shielded standard grade cable against heavily shielded $2000.00 audiophile grade cable. A more interesting (and relevant) comparison would pit a decently sheilded $100.00 cable against a $5000.00 "audiophile grade" cable. If listeners are actually perceiving a difference, IMHO, it's likely a result of EMI that would simply not be an issue with decent shielding.


 


All that tests shows, when put with other similar tests, that cables supposedly sounding better is no better than random.

post #51 of 60
Quote:
Originally Posted by fiver View Post


 

Quote:
Originally Posted by scompton View Post



Quote:
Originally Posted by fiver View Post


 

Quote:
Originally Posted by Uncle Erik View Post

One, tube gear is much simpler to maintain. You can get tubes for most things and should be able to into the forseeable future. Chips, not so much. When chips go out of production, they're almost impossible to replace. Practically speaking, tubes are better. Easier to work on and you can usually find replacements. If you're in for the long haul, tubes are the safer purchase.
 


How many times have you had to replace a "chip" in a solid state amp due to failure?

 

 


There are some very highly regarded vintage amps that are unrepairable, such as the Yamaha B2


 

Yes, it's true that you cannot buy replacement power JFETS for an esoteric design that was abandoned 30 years ago.

 

If you run esoteric tube amps using designs that were abandoned 30 years ago, I suppose you may possibly have a better chance of repair.


I was editing my post and got interrupted.  There are recent DIY designs  that are difficult to make because they're designed around a chip, and in case a tube, that are no longer made and essentially unobtainable.  The Starving Student being the tube example.

post #52 of 60


not exactly. I said a wire with higher impedence, resistance will help attenuate the line noise(very much how a line attenuator works). so technically, wires are very capable of changing the "sound" we preceive because of its conductance/resistance. Although  I cant exactly comment on it changing the sound signature of a speaker, since I havent yet observed such a change. or atleast that's what I attempted to imply biggrin.gif

Quote:

Originally Posted by dsf3g View Post




Your computer emits "line noise" and and you just know that better speaker wired could cure it, even though you haven't actually tried any?

 

post #53 of 60

Thanks for an interesting read!

 

Regarding the article ... there actually is one small issue with digital sampling at twice the frequency of interest (i.e. the Nyquist frequency).  While the Sharon-Nyquist Theorem correctly states that the frequency information is maintained, the phase and/or amplitude information is obscured. This was a lesson that one of my advanced controls professors taught me ... I hate to admit how long I had been ignorant of this ... Here is the simple way to convince yourself of this

1) Draw a simple cosine starting at time = 0

2) Draw the result of sampling that cosine starting at time zero at twice the cosine's frequency ... great! you just produced a string of 1, -1, 1, -1 ....

3) Now perform the same task as "2" but offset your initial sample point by just a little bit past t=0 ... now you have (for example) 0.9, -0.9, 0.9, -0.9 ... if you only have this information, how can you distinguish between a phase and an amplitude offset?

4) Of course the degenerate case is if you offset your sample by 90 degrees, where you get all zeros

 

The problem is that you have enough information to reproduce the frequency but not the phase & amplitude of the signal ... I am purposely avoiding the time-frequency analysis discussion for now because I need to get back to my thesis :)

 

In practice, one needs at least 4 times the sampling rate relative to the frequency of interest (2 for frequency, 1 for phase, 1 for amplitude ... in controls the rule of thumb is 10 to 20 times but these are noisier systems) to reproduce the signal's frequency, phase & amplitude ... and yes we're typically pretty crumby at absolute phase information, but the phase of one frequency relative to the other can be considered here as well.

 

I hope that this helps!

 

Thanks again for a great read!

 

 

post #54 of 60
Quote:
Originally Posted by InnerSpace View Post




I don't love grumpy old know-everything curmudgeons like the Audio Critic folks, but it's basic misunderstandings like the above that hurt the other side.  If a cable becomes part of a completed circuit, then a state of electric charge will propagate through said circuit at a speed approaching the speed of light.  But actual electrons will move very, very slowly - small fractions of a millimeter per second - and because audio circuits are AC circuits, they will then move right back to where they started.  In other words, they vibrate microscopically, but they don't really go anywhere.  The image of a cable being a pipeline through which electrons are flowing at lightning speed is entirely wrong, and it's a post-hoc image folks dream up to "explain" a basis for effects that may not exist.

 

Thanks for the explanation it is sorely needed.

 

I think one of the main effects at play on audiophiles is paranoia: "am I missing out on something," which is gratified by manufacturers claims and reiterated by social conditioning.  In one scientific test, subjects were shown three lines that are exactly the same length, and two actors also in the test insist that one line is shorter - and in a high proportion of subjects they in turn accept this is true even when they can physically see it is not.  While this is not entirely supported by the above example, I believe that our perception is very prone to subjective conditioning: peer pressure, but also paranoia.  Indifference is the best attitude, but it is hard not to be optimistic/excited when you spend big money on gear, or even when testing expensive gear - but incredulity in this matter is, I think, healthy and productive especially when in conflict with science and reliable method.

 

Some people are just far too naive and consequently buy gear that really isn't needed.  My favorite is digital interconnects - basically if you don't have noise, your digital cable is performing at 100% of the possible audio quality.  It is that simple - digital signals are ones and zeros, and are interpreted as ones and zeros.

 

Sure snake oil can be argued to do no harm, but peoples financial resources are finite, and money spent on questionable audio gear can go somewhere else eg. other reputable equipment rather than into the coffers of some snake oil salesman.  I am not saying that non-scientific comparisons are invalid, just that they are unreliable - therefore I would advise to collect as many opinions as possible (scientific as well as subjective) in order to make purchasing decisions.  Hell, at the moment I'm looking at building a silent PC as I am sure this will improve my listening experience, but shooting your neighbors dog might do just as well for your listening.

 

But lastly I think that being engaged with your audio gear, as well as your music selection, is a source of enthusiasm for your music, and promotes critical and empassioned listening as opposed to passive listening.  If that $2000 cable improves your passion for music, then it is probably doing you a favor, even if the audible change is insignificant.  That said there are probably cheaper alternatives for most people to achieve this, and also support musicians rather than cable designers.

 

post #55 of 60
Quote:
Originally Posted by broc3 View Post

Thanks for an interesting read!

 

Regarding the article ... there actually is one small issue with digital sampling at twice the frequency of interest (i.e. the Nyquist frequency).  While the Sharon-Nyquist Theorem correctly states that the frequency information is maintained, the phase and/or amplitude information is obscured. This was a lesson that one of my advanced controls professors taught me ... I hate to admit how long I had been ignorant of this ... Here is the simple way to convince yourself of this

1) Draw a simple cosine starting at time = 0

2) Draw the result of sampling that cosine starting at time zero at twice the cosine's frequency ... great! you just produced a string of 1, -1, 1, -1 ....

3) Now perform the same task as "2" but offset your initial sample point by just a little bit past t=0 ... now you have (for example) 0.9, -0.9, 0.9, -0.9 ... if you only have this information, how can you distinguish between a phase and an amplitude offset?

4) Of course the degenerate case is if you offset your sample by 90 degrees, where you get all zeros

 

The problem is that you have enough information to reproduce the frequency but not the phase & amplitude of the signal ... I am purposely avoiding the time-frequency analysis discussion for now because I need to get back to my thesis :)

 

In practice, one needs at least 4 times the sampling rate relative to the frequency of interest (2 for frequency, 1 for phase, 1 for amplitude ... in controls the rule of thumb is 10 to 20 times but these are noisier systems) to reproduce the signal's frequency, phase & amplitude ... and yes we're typically pretty crumby at absolute phase information, but the phase of one frequency relative to the other can be considered here as well.

 

I hope that this helps!

 

Thanks again for a great read!

 

 



 

So does that mean that upsampling is a sound practice?

post #56 of 60
Quote:
Originally Posted by Syan25 View Post





 

So does that mean that upsampling is a sound practice?

 

The short answer- upsampling adds no new information to a digital signal, but I can come up with a couple of situations where an upsampled data stream could aid in the transition back to analog


The longer answer - Upsampling in its simplest form does not add any information ... the process basically fills in the points between the original samples with interpolated values (an oversimplified way to think about it is that of linear interpolation where a straight line is used to connect two points and any previously undefined intermediate values are assumed to fall on that line ... no additional information about the original signal is added, but now you have assumed values between those points). For the signals that we are discussing here, a "perfect" low pass filter is used to create the interpolated values. Again, no new information is added, but you have more points (because all of the new points directly rely upon the interpolating function and the original points ... if any added point during the upsampling varied from this, then new information would be added.)

 

There are likely others on this forum that are better informed than I am on the following ... but here goes my best attempt at why one might want upsampling - I can imagine situations where

1) by upsampling, the digital images that are centered at multiples of the sampling rate are moved further away from the frequencies of interest and are therefore more easily filtered away

2) since the digital filtering that results in the interpolated values should be free of noise (neglecting clock jitter for now), the "perfectly interpolated", higher temporal resolution of the resulting upsampled digital signal should make the DAC's job easier

 

By the way, I welcome any additions and/or corrections ... I'm approaching this with a technical skill set that is useful for these problems, but applying these tools to audio is new for me

 

Thanks!


Edited by broc3 - 3/6/11 at 8:40pm
post #57 of 60

Thanks - because I have been using my new Yulong D100 DAC via USB - and it recommended setting audio playback to 24bit/96khz - but my PC is having a hard time doing that without latency spikes...and my music files are ALAC - 16 bit/ 44.1 khz...

 

I would say that you explained this very well! Cheers!

post #58 of 60

Most interesting reading. Most parts were known, but it's good to hear them again and again, one quickly dreams about these outrageously price Hi-end stuff...

Now, I believe in superiority of a good electronic design over a bad one. One can see in simple measurements the effects of such pattern or implementation. Now check scientifically that such components is "better" than this other one, does not imply it will be reflected in the sound at all.

 

So, Basically, a headphone amp is useful if your source is not correctly designed to drive your hi impedance voltage hungry cans. Most DAPs these days are so small and fed by so shallow volts that...

 

post #59 of 60

Thanks for the article, it was very timely. Like a bucket of cold water on my overheating mind after two days on this site. I particularly liked the part about tube amps:

 

Even the worlds best designed tube amplifier will have higher distortion than an equally well-designed transistor amplifier

 

It reminded me the debates about color reproduction on photographic forums. You see, true color reproduction actually looks dull and unpleasant to human eyes, that is why most photographers introduce some degree of color distortions during post-processing (more than "natural" saturation, warmth, etc or vise-versa eliminating color completely). Even though the results don't look exactly the same as the real scene, they are more pleasant for the viewers. With color, photographers are trying to compensate the lack of other emotions that could only be achieved by being physically on the real scene. I think the same is true in audio world - the distortions introduced by tube amplifiers are more pleasant to the ears than the "true" sound of more advanced solid amplifiers. The resulting sound contains more emotional impact; therefore it is more desirable despite certain deviations from more accurate sound. So truly, what we are looking for is NOT the most REALISTIC sound, BUT the most pleasant and emotional sound. Of course, in photography clarity and sharpness are all vital components of the IQ as well as color reproduction. So I am not trying to say that we can tolerate all sorts of distortions in music. it just I don't believe that we should be obsessed with achieving zero-distortion either as we may through the baby with the water in the process.

 

 

post #60 of 60
Quote:
Originally Posted by dsf3g View Post




Your computer emits "line noise" and and you just know that better speaker wired could cure it, even though you haven't actually tried any?

 

As for that article, it's funny. The author laments that Pear Audio backed out on an ABX of their performance claims vs. a standard set of Monster cables, because it "makes it look like Pear isn't confident that its cables would prevail, even with an experienced listener like Fremer." So instead, the author links to a second article that details results of "a similar but undoubtedly less rigorous test" that purports to show that it is possible to distinguish between high-end audio cables and regular "hardware store" grade audio cables. This test had a sample size of 39 people, of which 24 picked the "right" cable and 15 picked the wrong cable. Just off the bat, assuming a perfect experiment, there is a 10% chance of achieving these results just by guessing. Those odds aren't bad, but I'm not sure I'd base a $5000.00 purchasing decision on them. More significantly, they compare lightly shielded standard grade cable against heavily shielded $2000.00 audiophile grade cable. A more interesting (and relevant) comparison would pit a decently sheilded $100.00 cable against a $5000.00 "audiophile grade" cable. If listeners are actually perceiving a difference, IMHO, it's likely a result of EMI that would simply not be an issue with decent shielding.


 



Good computer audio equipment filters these noises, which are of a high enough frequency not to be troublesome. For higher bandwidth signals, like HDMI cables, ferrite chokes are sometimes used at the beginning and end of a cable as a passive filter.

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