Digital Audio Myths - Listening on a PC

At last I found a good source of information - a page which describes both audiophiles and skeptics. I took the liberty of highlighting remarkable passages which I find remarkable and aggree with in red.

http://en.wikipedia.org/wiki/Audiophile

Audiophiles

• There are problems in applying double-blind methods to comparison of audio devices; audiophiles assert that a relaxing environment and sufficient time, measured in days or weeks, is necessary for the discriminating ear to do its work; further, that the introduction of the switching apparatus, involving as it does either another metal connection at the switch or another level of electronic processing with solid state switches, obscures the differences between the two signal sources being tested.
• While tubed electronics are less linear than solid state at high signal levels, they are claimed to be significantly more so at lower (sub-one-watt) levels; and it is argued that most musical signals spend most time at these levels. Paraphrased, "The first watt is the most important."
• Total harmonic distortion has been proved by scientific testing to correlate only poorly with perceived sound quality; the type of distortion is very significant. For instance, distortion by even harmonics has been shown to be less objectionable than by odd harmonics.
• In general, proponents of "high-tech" solutions (such as the earliest CDs) dismiss complaints of audiophiles on the grounds of the new systems' ideal behavior, rather than real world behavior using real world components. Often this is followed by the introduction of newer, improved components which are sold as lacking the problems of the prior generation, which had been described as "audibly perfect" at the time. For instance:
• In defense of their preference for analogue over digital formats, audiophiles point out that the process of converting a bit-stream to an analogue waveform requires heavy filtering to remove spurious high-frequency information, and that it should be expected that such filtering should involve some signal degradation and a large amount of phase shift in the passband. They point out that commonly used consumer grade digital to analog converters (DACs) exhibit very poor linearity at low levels. Both problems, at first dismissed, were then addressed by such solutions as digital filtering, oversampling, and use of 20 or more bit DACs. The introduction of the new higher-bandwidth "high-resolution" music formats was a tacit admission of the reality of this issue. Musician Neil Young, for example, was a harsh critic of the sound of the original CD format, but has approved of the sound of the Super Audio CD (SACD) with its greater "safety margin" between its ideal behavior and the requirements set by the limits of human hearing.
• Audiophiles were insistent on the sound degradation introduced by large levels of negative feedback in amplifiers, long before the universal acceptance of the fact that, while this technique was indeed beneficial to amplifier stability and test results using steady-state waveforms, it was inherently problematic for constantly changing waveforms as in real music, and resulted in amplifiers that tested well and sounded bad.
• Audiophiles were insistent on the improvement in sound quality they heard with higher quality capacitors (such as tantalum) in place of or bypassing large electrolytics or paper capacitors in the signal path, long before the universal acceptance of the fact that such capacitors, involving as they do significant inductance due to their spiral-wound construction, do interfere with passage of the highest audio frequencies.
• Audiophiles were experimenting with improved power supplies for CD players in order to block them as a path for the mechanical section of the CD drive and the digital section around the DAC to affect the audio section. In particular, the concern that voltage fluctuations in the power supply from the load of the motor would affect the internal digital clock of the digital section, and that such digital clock "jitter" would cause audible distortion was explored by audiophiles long before it was found to be valid by manufacturers.
• Although clearly audible levels of very objectionable distortion were demonstrated early in the digital audio era by simply running a signal source through an analog to digital converter and the result through a digital to analog converter, and electronically subtracting that result from the source, this demonstration was ignored by the digital audio proponents, much as the inability to demonstrate differences by double blind testing was ignored by the audiophile camp.
• Audiophiles were experimenting with room acoustics long before component manufacturers began to consider them a factor.
• Audiophiles noted the differences in response speed between various speaker drivers used in a single speaker system, and began experimenting with fewer drivers, stepped speaker boxes, and so on.
• Many vendors or retailers offer free trials, or money-back guarantees if their products are unsatisfactory, and they remain in business.
• Despite a lack of formal education, experienced "listeners" can be relied upon for objective advice on how equipment sounds, and whether its worth the price.

Skeptics

• There are reports of Double-blind tests which fail to support audiophile claims that they can easily perceive significant differences between very similar musical components.[1]
• Listening tests are notoriously unreliable; for instance, Edison showed that entire theater audiences were unable to distinguish between the sound of an orchestra or a playback by his recording system, which today would be regarded as ludicrously poor in quality. Similarly, early CDs and CD players were accepted as having fantastically great sound quality; those exact same systems today are regarded as fatally flawed, while analog systems from that period have not similarly fallen in public assessment of quality.
• Similarly, repeatability is poor for evaluation of components between various listeners, or even the same listener under different circumstances; this contrasts with the superficially similarly esoteric oenophile world, where repeatability of blind tests is surprisingly good.
• Measured audio distortion is immensely higher in electromechanical devices such as speakers than in purely electronic components such as CD players and amplifiers, making it hard to believe that subtle differences in the latter can have an appreciable effect on music quality.
• Similarly, acoustic behavior of the listening room, and the interaction between speakers and the room acoustics, is immensely more variable than variation between electronic components; in an electromechanical system such as a speaker, such interaction is reflected in the interaction between speakers and the amplifiers which drive them, so that the entire difference in sound quality between amplifiers is often postulated as merely either the ability to control the behavior of "difficult" speakers well, or else just a lucky combination of speaker, amplifier, and room which works well together.
• Minute differences in loudness have been demonstrated to be perceived as differences in sound quality rather than loudness, with the slightly louder system sounding better; so that tremendous care must be taken in matching sound level, using sensitive sound pressure meters, when comparing systems if the results are to have any validity at all; this is usually not done.
• Audiophiles often totally disdain all attempts to categorize differences in sound using instrumental measurements, despite the work of such combination audiophile-engineers as Bob Carver, who have repeatedly shown that by tailoring the transfer function of any system with a relatively simple sound-shaping network, they can make it sound indistinguishable from any other system, as requested.[2][3]
• Audiophiles often prefer the use of vacuum tube rather than more modern solid state electronics, despite their substantially-higher measured total harmonic distortion. When this is pointed out, they often claim that the distortion is "warmer" or "more musical" than that of a transistor amplifier. Interestingly, the relatively soft distortion characteristics of tube amplifiers are used regularly in high-end guitar amplifiers; in this case the loss of fidelity is intentional and even characteristic of the electric guitar sound, and transistor-based amplifiers are often frowned on for guitar use due to the harsh clipping artifacts created by a distorted transistor amp.
• Audiophiles regularly make strong claims for the superior quality of music reproduction from (vinyl) records on a turntable, compared to modern digital alternatives (which, among other things, are free from "click and pop" problems and background noise), even though compact disc audio in particular is designed to have a wider dynamic range than vinyl.
• Audiophile equipment designers can obsess over seemingly irrelevant details; for instance, the almost universal requirement to reproduce frequencies higher than 20 kilohertz, even though some kinds of equipment will not reproduce anything higher than 15 or 16 kilohertz (for example, FM radio and vinyl records).
• Some audiophile practices seem driven by fashion, such the late-Eighties vogue for marking the edges of CDs with a green felt marker, or the practice of suspending cables above the floor on small racks. Skeptics argue that the laws of physics are not subject to fashion.
• The prices of audiophile products can seem remarkably high, even if one believes in the benefit conferred. It is quite possible to spend over a hundred thousand dollars for speakers, and tens of thousands for amplifiers and CD players, or over a thousand dollars for a power cable.[4] [5]
• Vendors of audiophile products regularly make fanciful and frankly unscientific claims for the results produced. At one point a company called Tice Audio sold what appeared to be an ordinary clock radio which, it was claimed, would improve the quality of a playback system if plugged into the same electrical circuit, by causing some mystical change in "electron energy".
  Vendors such as Shun Mook market a variety of disks and clamps which, when attached to audio components, are claimed to improve sonic performance.
• In particular, vendors of audio cables have been prone to claims, and to pricing, which strain credulity. There have been audio cables which are filled with water, which glow in the dark, and which come with a separate AC cord which must be plugged in to power the workings of the cable. Those versed in the physics of electrical conductivity often find the prices paid for cables to be laughably high, and at best consider them a form of jewelry.
• Some audiophile claims, while superficially based on accepted physical principles, apply them to circumstances where they are not relevant; for instance the skin effect which relates the efficiency of cables to the frequency transmitted is often referenced with regard to audio frequencies, where it is not significant.
• Many (not all) of the most outspoken audiophile insiders, including reviewers, columnists and pundits lack engineering training and objective credentials. This gives rise to a credibility problem and most will fully admit a lack of understanding as to the technical merits of what they are analyzing, but nevertheless praise a product's innovation and performance. (does this remind you of someone?)

Overall the audiophile world is looked upon by skeptics as being a hotbed of gullibility and fraud, its marketing engine driven primarily by either a constant desire for oneupsmanship or a more benign desire to tinker with equipment; in particular, the tinkering drive is fed by wild claims for minor parts of the system such as cables. In turn, skeptics are often harshly dismissed by dedicated audiophiles as "meter men", people who simply refuse to recognize what the audiophiles consider obvious. The debate is rather heated in certain quarters, and even James Randi chimed in on the issue in 2005.