Myths (Vinyl)

Myth: Vinyl sounds better than CD

No discussion about this topic would be complete without acknowledging that a person's subjective perception is their reality.

Many people prefer listening to music on vinyl rather than on CD or digital formats. A majority of those people do so because they honestly perceive the sound to be better. "Better" meaning more natural, less artificial, more true to the original studio recording, more organic etc, even when unsupported by objective measurements of fidelity. For such people the statement that "vinyl sounds better than CD" is not a myth but a fact.

There are many examples where a vinyl record may sound better than its equivalent CD for extremely specific reasons. Conversely there are many CDs that may sound better than a vinyl record for specific reasons.

The statement "Vinyl sounds better than CD" has nothing to do with objective measurements. The word "sound" refers to waves interpreted by our ears, not a piece of measuring equipment. The word "better" is subjective, based on personal experiments,comparisons and observations, and in the case of sound quality is very personal. We could make the statement "CD sounds better than Vinyl" and the previous statement would apply.

Any time a person makes a claim about anything sounding better than another thing, we need to be understanding that the statement has no bearing on technical or objective measurements of fidelity, but is based on personal perception.

However it must also be recognised that some sounds would be universally recognised as better than other when measured comparatively e.g. a fart compared to birdsong.

Myth: Vinyl requires a better-sounding master because it is physically incapable of reproducing the hypercompressed sound mastered to CD

Different masters can substantially improve or reduce sound quality. Some have less background noise. Some alter the dynamic range. There are other mastering techniques that can also affect the sound.

There are documented instances of different masters being used on vinyl releases compared to CD releases. One notable example is The White Stripes' Icky Thump. However, there are also instances of the same masters being used on vinyl releases compared to CD releases. In fact, if you purchase an album produced in the last two decades on vinyl, it is likely that the master will be no different than the one used on CD. Alternative masters for vinyl cost money, and mastering is a significant cost of producing a record. The reason for different masters is that producers possibly view digital media (like CD) and analog media (like Vinyl) to be different in nature, so they might produce a different master for each medium. Some even believe that Vinyl will automatically yield a superior sound, despite the well known technical limitations and disadvantages compared to the CD.

The technical details behind this myth are as follows. The cutting heads used for creating the vinyl lacquer (or metal mother) are speaker-like electromechanical devices driven by an extremely powerful amplifier (several hundred watts). At extremely large/fast cutting head excursions, the cutting head coils may physically burn up, much like how a speaker's voice coils may be destroyed by an excessive current. Also, the diamond cutting head stylus may prematurely wear or break. This places important constraints on the maximum levels that can be recorded to a record.

A very high power output is required to cut grooves with a high acceleration. Acceleration at the same signal amplitude is higher for higher-frequency signals. Heavily clipped and limited CDs in the modern mastering style have more high-frequency content than earlier masters. In general, increasing the perceived volume of a record - whether by increasing the recording level or by limiting/clipping/compression - raises the cutting head average power.

Additionally, during playback, the turntable's stylus has limits on what grooves it can successfully track. Cartridges can only track grooves of a finite modulation width (measured in microns) that decreases in frequency. For instance, a cartridge may only be able to track a 300 µm-wide groove at 300 Hz, and yet only 50 µm at 20 kHz. This also places limits on the acceleration and velocity limits the record master can take.

The most obvious way to work around these issues is simply to reduce the recording level of the vinyl master. That's exactly what vinyl mastering houses do, using multiband limiters that dynamically reduce the treble content of the master, to limit the cutting head power usage.

Effect of vinyl mastering on dynamic range

A related myth is that when vinyl has a higher dynamic range than CD, it means the audio was sourced from a different, more dynamic master, and that the difference in dynamics will be audible.

It is true that recordings on vinyl sometimes have a spikier waveform and a measurably higher dynamic range than their counterparts on CD, at least when the dynamic range is reported by crude "DR meter" tools that compare peak and RMS levels. The higher "DR value" could indeed be a result of entirely different master recordings being provided to the mastering engineers for each format, or different choices made by the engineers, as happens every time old music is remastered for a new release.

But even when the same source master is used, the audio is normally further processed when mastering for the target format (be it CD or vinyl), and this often results in vinyl having a spikier waveform and higher DR measurement. There are two types of processing during vinyl mastering that can increase the DR measurements and waveform spikiness, thus reducing the RMS and increasing the basic DR measurement by perhaps several dB:

• The audio is subjected to low-pass or all-pass filtering, which can result in broad peaks becoming slanted ramps.
• The amount and stereo separation of deep bass content is reduced for vinyl, to keep the stylus from being thrown out of the groove.

It is quite possible that these changes are entirely inaudible, despite their effect on the waveform shape and DR measurement.

The dynamic range of the waveform is also affected by the vinyl playback system; different systems provide different frequency responses. Factors include cartridge, tonearm, preamp, and even the connecting cables. A vinyl rip with weak bass may well have a higher reported DR value than a rip of the same vinyl on equipment with a stronger bass response.

Myth: The vinyl surface is heated to several hundred degrees on playback, and repeat play of the same track should wait at least several hours until the vinyl has cooled

Professional estimates for the stylus surface temperature during playback are ~150-260 °C (300-500 °F). Obviously, the temperature of the record is at or close to room temperature except at the stylus contact point - otherwise the record would completely melt. Back-to-back playback will introduce slightly more distortion than a fresh play. This is believed to be a temporary effect and goes away after approx. 10 minutes.

Repeated playback (no matter what the timeframe) carries the risk of permanent damage. Obviously, records are observed to wear out with repeated play. No published evidence exists of back-to-back playback causing any more permanent damage than if repeated plays are separated by any longer period of time.

Myth: Proper vinyl playback is click-free

Pops and clicks are often not audible during a song on a well-maintained record and should not distract from the listening experience. No evidence exists of a record that is shown to be played back with absolutely no pops or clicks whatsoever. They are introduced at virtually every stage of production, from cutting the lacquer to the pressing to the playback itself. Some pops and ticks are pressed into the record itself.

Some pops and ticks result from static discharges during playback. However, this may be mitigated by the use of topical treatments on the record.

Because of the lack of evidence for a tick-free record and the engineering factors making such a record extremely rare, it is quite likely that no record exists that is truly free from all pops and ticks.

Myth: Vinyl is better than CD because it reproduces higher frequencies than CD and avoids anti-aliasing filter issues at the frequencies CDs can reproduce

The recording/tracking ability of vinyl is easily at least 50 kHz depending upon the cartridge and stylus profile, and perhaps as high as 100 kHz. The most notable proof of this is the CD4 quadraphonic system which relied on a 45 kHz bandwidth to be accurately reproduced. That said, the high-frequency response accuracy of vinyl varies tremendously. Amplitude deviations of 5-10 dB or greater are not uncommon in the 20 kHz range for many records, but many records are cut faithfully to the source material and a high quality record player and cartridge combination should have no problems faithfully reproducing the recorded sound.

More discussion: http://www.hydrogenaudio.org/forums/index.php?showtopic=98178

Playback of ultrasound frequencies is still not guaranteed. Many MM cartridges have resonant peaks defined by the preamp loading, or stylus tip resonances defined by the cantilever, that attenuate high-frequency content, however these issues are minimised with the use of high quality cartridges, and correct capacitive loading of the phono preamp. Moving Coil cartridges are unaffected by capacitive loading due to their design.

When groove wear does occur, it occurs much faster at high frequencies than at low frequencies. For modern styli, this is not as much of a concern and tests demonstrate that a record can be played up to 1000 times before there is any measurable increase in distortion as a result of record wear, although this is unlikely. On every play, there is the potential for damage, as when the stylus forces a grit particle into the vinyl.

Commonly there is audio content up to 23-24 kHz on many vinyl records. Many instruments have overtones up to 100 kHz. See article: http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

There are rarely, if ever, any ultrasonic frequencies for vinyl to preserve. In audio recordings, such frequencies, when present, are normally low-energy noise imparted by electrical equipment and storage media used during recording, mixing, and mastering. Although some musical instruments can produce low-energy overtones in the ultrasonic range, they could only be on the vinyl if every piece of equipment and storage medium in the recording, mixing, and mastering stages was able to preserve them, which is unlikely even in modern recordings, since the average microphone or mixing console is designed only with audible frequencies in mind. Even if the overtones were preserved all the way to the mastering stage, mono and stereo lacquer cutting equipment typically includes a low-pass filter to avoid overheating the cutting head with ultrasonic frequencies. However, the commonly found audio information up to 23-24 kHz is still present at significant amplitude on many vinyl records.

It is, however, worth mentioning that it's highly unlikely for anyone to actually be able to hear frequencies above 20 kHz, which means that a regular CD covers whole hearable frequency range.

Myth: Vinyl is better than digital because the analog signal on the vinyl tracks the analog signal exactly, while digital is quantized into steps

Frequency resolution

The Nyquist-Shannon sampling theory states that continuous-time (analog) signals and their corresponding discrete-time (digital) signals are mathematically equivalent representations of any bandwidth-limited signal, provided the sample rate is higher than 2X the bandwidth. All relevant advantages and disadvantages result from implementation details rather than analog versus digital signal representation method. Perhaps the most common method of storing a digital signal is with pulse code modulation (PCM). PCM is used on CDs and DVD-A.

PCM is sometimes characterized as producing a jagged, "stair-step" waveform. This is only partially correct; analog-to-digital conversion (ADC) does indeed use a sample-and-hold circuit to measure an approximate, average amplitude across the duration of the sample, and digital-to-analog conversion (DAC) does the same kind of thing, generating a rectangular-ish waveform, but this output is always then subjected to additional filtering to smooth it out. Effectively, the ADC output sample values are interpreted as a series of points intersected by the waveform; the DAC output is a smooth curve, not a stair-step at all. Additionally, modern ADC and DAC chips are engineered to reduce below the threshold of audibility, if not completely eliminate, any other sources of noise in this conversion process, resulting in an extremely high correlation between the input and output signals. (Perhaps a better explanation: xiph.org's "Digital Show & Tell" video)

A related myth is that components of the signal near the Nyquist frequency must be square waves on CD (or digital media), and that vinyl (or any analog media) preserves pure sine waves. The premise is false. A square wave, or any wave that's not a perfect sine wave, is the sum of multiple pure tones (sine waves), by definition. So if you have a pure 22.05 kHz signal on CD (i.e., sample values +n, -n, repeatedly), the DAC may first construct a square wave, but the reconstruction filter then filters out everything above the Nyquist frequency, leaving behind a sine wave. The principle is the same even in complex waveforms. The end result is that the uppermost frequency components on CD are no closer to being square waves than they are on vinyl.

Jitter

Another impact of finite sample rate is the possibility of jitter in the sample clock. If the clock is not exactly on time, the jitter causes distortion, sometimes called "jitter error". Jitter error is unique to digital, and is vanishingly minuscule, a tribute to the many years of effort that went into minimizing it. By the time the earliest CD players came out, distortion produced by jitter was well below the threshold of audibility.

Since it does not use discrete timing steps, analog gear does not have jitter, per se, but wow and flutter—large and small speed variations—occur in all analog gear. The scale of wow and flutter is far greater than that of digital jitter, and is far more likely to produce audible effects.

Time resolution

PCM can encode tiny delays that are actually limited by the bit depth and are far smaller than the time period of a single sample. Time delays of 1µs or less—a tiny fraction of the sample rate—are easily achievable. The theoretical minimum delay is 1 nanosecond or less. (Proof here.)

Dynamic range

Another significant impact of finite quantizing resolution is finite dynamic range. As implemented, the bit depth of CD and DVD digital audio formats accommodates a higher dynamic range than vinyl is capable of. The only signal that can exist 'between the bits' of a CD is drowned out by random noise from the vinyl surface grain.

Quantization error

Another possible impact of finite resolution is systematic rounding and truncation error (see Quantization_noise). When making use of the available headroom afforded by 16 bits, the inherent noise from vinyl playback is likely enough to swamp this error to the point that vinyl is already self-dithering (see Dither). As of yet, no one in the hydrogenaudio community has adequately demonstrated that quantization error arising from 16 bits is high enough to warrant even the use of dither when working with vinyl.

Vinyl is often sourced from digital anyway

Since the mid-1970s, vinyl mastering houses began using digital delay lines instead of analog delays on the signal going to the lathe that cuts the spiral groove. So even in the increasingly unlikely event that 100% of the recording, mixing and mastering was done entirely using analog gear and media, the end of the vinyl mastering process may well have involved a conversion to digital and back.

Further comparisons

Analog encoding has many measurable and audible faults, potentially including harmonic distortion, noise and intermodulation distortion. These distortions have invariably measured higher than for digital formats, including CD.

Tracking error is due to the use of analog encoding with a stylus that contacts the medium, manifesting as distortion and possibly also cyclic wow with subsonic noise if the pressing is off center from the spindle hole. Wow, flutter, footsteps and feedback are other errors due to the transport mechanism and transducers used with vinyl. Digital storage has none of these errors.

In addition to its advantages for audio storage, digital also has advantages for audio production. When a large number of individual audio sources are sampled from source into 24 bits at high sample rate, then digitally processed with effects and mixed into a standard multichannel format, the resulting mix is superior in dynamic range and harmonic distortion to what could be achieved with legacy analog processing and mixing, due to the elimination of thousands of noise-producing and distortion-producing analog components such as potentiometers, resistors, and transistors. Some digital effects such as lossy codec compression to reduce overall bandwidth (thus reducing storage space) without sacrificing psycho-acoustic realism are impossible to implement in analog, and require a digital format anyway.

Audio DVD or A/V Blu-ray medium is used in order to preserve the fidelity and channel grouping of modern multichannel recordings. Audio CD can also be used for such digital mixes, but at lower dynamic range and sample rate, and with only two discrete channels, with no lossy compression to reduce storage space. A third alternative is to rip to data disc and play back on computer via digital bus to a multichannel home theater receiver or equivalent.

In any of these preceding three use cases, digital is superior to analog at both mastering and end-user stages, and represents an advance in the total sound production signal path rather than simply storage improvement.

Myth: Vinyl has greater resolution than CD because its dynamic range is higher than for CD at the most audible frequencies

The dynamic range of vinyl, when evaluated as the ratio of a peak sinusoidal amplitude to the peak noise density at that sine wave frequency, is somewhere around 80 dB. Under theoretically ideal conditions, this could perhaps improve to 120 dB. The dynamic range of CDs, when evaluated on a frequency-dependent basis and performed with proper dithering and oversampling, is somewhere around 150 dB. Under no legitimate circumstances will the dynamic range of vinyl ever exceed the dynamic range of CD, under any frequency, given the wide performance gap and the physical limitations of vinyl playback. More discussion at Hydrogenaudio.

Myth: Adding a penny to the headshell improves tracking/sound

The trackability of a cartridge is related to the mechanical parameters of the tonearm and stylus assembly. Adding weight to the headshell, and adjusting the counterweight to compensate, increases the effective mass of the tonearm and reduces its resonant frequency. If the resonant frequency is excessively high (e.g., 15-20 Hz, as measured by a test record), the increased mass may improve trackability by moving the resonance out of the audible range. Otherwise, it will generally only reduce trackability.

Adding weight to the headshell without adjusting the counterweight may improve the ability of a severely damaged stylus to track the groove, or the ability of an undamaged stylus to track a record in poor condition, but the excess weight almost certainly damages the record. A stylus in good condition will yield optimum sound with minimal damage to the groove when used within the tracking force range it's designed for. If the sound/trackability improves when exceeding this recommended range, then the record or stylus should be replaced.

Myth: A cartridge is permanently damaged and should be replaced if the stylus appears even slightly bent

Cartridges and styli are hand-built and always have some finite tolerance in their construction. No stylus has a cantilever that is perfectly straight.

That said, a severely bent stylus can cause azimuth and alignment errors which may be audible. In extreme cases, it can cause record damage. However, the cartridge itself is unlikely to be at fault; only the stylus would need to be replaced.

In the case of Moving Coil this is not correct. The stylus is part of the unit and the cantilever/stylus assembly cannot be removed. Stylus can be re-tipped but not just simply replaced like a moving magnet. Its often more costly to re-tip than to replace. There are cartridges that are indeed perfect (straight) in manufacture using elements that stay straight yet can flex in service.

Myth: Belt-driven turntables are better than direct-drive turntables

General claims of improved musicality and audio quality of belt drives are subjective and have no scientific basis.

In the secondhand market, neither type of drive holds its value any better than the other.

A poorly-built drive of any type will not necessarily fare better than any other.

There is a common myth that a direct drive will "hunt" for the correct speed and cause audible speed variations. This has no basis in reality.

In favor of belt drives:

• Belt drives are generally easier and cheaper to implement, improve, and repair than direct drives.
• Since belt drives are cheaper, a belt-driven turntable can come with a more expensive tonearm than a direct-drive turntable in the same price range.

In favor of direct drives:

• Well-built direct drives can match or outperform well-built belt drives in terms of rumble.
• Well-built direct drives can match or outperform well-built belt drives in terms of speed tolerance.
• Direct drives tend to last a very long time without maintenance; belt drives need new belts on a semi-regular basis.
• Belt drives tend to have noisier motors as compared to direct drives in the same price range.

[A comment: there seems to be a general perception, that driving a turntable with high momentum using an Idler Wheel, or a belt drive can accomplish better transient response. There are a fair amount of reports stating that claim although I have not seen any scientific proof of the claim. In comparison most direct drives are very low momentum.

In regards to Belt driving, much of the problems stem from friction in the main bearing and inconsistency in the belt itself. A study at the Danish Technical University some 30 years ago revealed that a belt drive utilizing an airborne bearing reduced the influence from the belt itself.]

References

(More references and links back to Hydrogenaudio discussion threads are needed. Please help if you can!)