Playback and Recording (Vinyl): Difference between revisions

From Hydrogenaudio Knowledgebase
(Added a myths section with some properly controversial comments.)
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''The playback speed of the turntable must be within 0.3% of 33 1/3 RPM at all times - or 5 cents. Variations of pitch must stay witin the 5-cent requirement and the modulating frequencies must not be audible.''
''The playback speed of the turntable must be within 0.3% of 33 1/3 RPM at all times - or 5 cents. Variations of pitch must stay witin the 5-cent requirement and the modulating frequencies must not be audible.''


Shockingly, this is extremely hard to achieve in belt-drive turntables for a number of very important reasons. Good direct drives are much better at this.
Shockingly, this is extremely hard to achieve in belt-drive turntables for a number of very important reasons. Good direct drives are much better at pitch. (Bad direct drives are much worse at flutter.)


==Low rumble==
==Low rumble==

Revision as of 19:51, 25 April 2006

Why vinyl?

Why invest in an obsolete, 50+ year old music medium?

  • Used vinyl is often extremely inexpensive - 50 cents to two dollars a disc is somewhat common. Vinyl is a very cheap way to expand your collection in older artists that you cannot justify spending $15/CD on listening to.
  • Some albums have simply never been released on CD.
  • Some album art is better suited to the larger scale of LP covers and sleeves.
  • The mastering of an original LP release is often considered superior to a CD remaster of the same release. This can be for any number of reasons, including:
    • Increased use of compression and limiting on the CD release, reducing dynamics
    • The master tapes have often degraded in the time between the LP and CD releases
    • The equalization and even mixing of some CD releases is radically different than on the LP releases. For instance, many Zappa LPs have had entire drum tracks replaced for the CD release.
  • Properly maintained vinyl is of a surprisingly good quality and is often not objectionable.

Why not vinyl?

There are several disadvantages.

  • Vinyl is particularly finicky to maintain and easy to damage.
  • Surface noise, while often inaudible, will always be present, even on a brand new LP.
  • The quality of a record often cannot be determined until you play it, increasing the risk of the purchase. Even brand new, sealed LPs can have significant pressing and warping problems.
  • Not portable.
  • Investing in a reasonable vinyl system is hundreds to thousands of dollars more expensive than investing in a reasonable CD/computer system. Financially, any benefits of the cheaper media must be compared against the amortized cost of the equipment needed to play and maintain it.
  • There is also a not insignificant running cost in playing LPs. The stylus does wear out, and top class cartridges use stylii costing several hundred (or even thousand) dollars. Playing one LP with an audiophile cartridge can easily cost over a dollar in stylus wear.
  • Records are large and heavy. Transporting them correctly is logistically difficult.
  • Many record stores have a considerable markup on used LPs and it may be hard to find records for cheaper than $10 in some stores. This makes it much harder to completely justify vinyl on a financial basis.
  • Some vinyl has a very high collector's value which makes it nearly impossible to locate for prices cheaper than CD.

Vinyl Myths and Misconceptions

Note: These are preliminary notes, are a little opinionated, and are subject to change. Please edit as appropriate or comment on the discussion page.

  • The vinyl surface is heated to several hundred degrees on playback, and repeat play of the same track should wait until the vinyl has cooled.
  • Proper vinyl playback is click-free.
  • Vinyl is better than digital because the analog signal on the vinyl tracks the analog signal exactly, while digital is quantized into steps.
  • Vinyl is objectively worse than digital.
  • Vinyl is objectively better than digital.
  • Adding a penny to the headshell improves tracking/sound.
  • Vinyl sounds better with the dustcover on/off.
  • A cartridge is permanently damaged and should be replaced if the stylus appears even slightly bent.
  • A record cleaning machine is required for proper playback.

Vinyl Availability

Note that a lot of this info is currently US centric.

The "market rate" for LPs depends primarily on the collector's value. Mass-produced and unpopular LPs will not cost more than a dollar. Original pressing Beatles LPs are usually over several hundred dollars. Jazz records tend to be very expensive. Classical records tend to be quite inexpensive. Rock, blues and electronica lie somewhere in the middle.

Depending on how clued the store is to the by-the-book market prices of vinyl, prices can range anywhere from 50 cents on up. Record stores tend to have the highest prices and charity stores the lowest, but there are always exceptions.

  • Many cities have local record stores that specialize in certain genres. Check your yellow pages and local music listings for ads.
  • Half Price Books (US) tends to have extremely good vinyl selections. Vinyl is not transferred between stores, so the quantity/quality varies widely even by the neighborhood.
  • Goodwill, Salvation Army, and other charity stores often have good deals on vinyl.
  • The Austin Record Convention http://www.austinrecords.com/ has a very, very large quantity of LPs. Biannual. Similar conventions exist in many other large cities.

Playback system

To play a record, you need the following:

Turntables

See article: Turntable

Pickup Cartridges

See article: Cartridge

Phono Preamplifiers

See article: Phono preamplifier

Component Availability

Buying a turntable now is a lot harder than it used to be, but there are still plenty of options. A new turntable is usually much less hassle to set up than a used turntable for a new user. Maintenance and calibration is usually much less of an issue. However prices are much higher (30-100%) than equivalent used models.

As a general rule, do not purchase used cartridges, ever. They are the component that wears out the fastest on turntables during normal operation, and are the easiest to permanently damage. Buy them from reputable local or online sources. They do not have particularly difficult shipping requirements.

New

Hifi stores

The traditional place to obtain a turntable is at a local hi-fi shop. These are becoming an endangered species in the US - many have folded or switched to home theater and car audio - but most cities usually have at least one store selling audiophile kit.

Advantages:

  • Most hifi stores are locally owned and operated.
  • Shipping issues with turntables are already taken care of. Turntables are rather notoriously hard to ship correctly.
  • Hifi stores will usually tune/calibrate turntables free of charge on purchase.
  • You may be sending your table back to said store for maintenance, even if you purchase it elsewhere. Setting up a rapport is good.
  • Product support is often (possibly always) better from hifi stores than from any other source. A no-questions-asked tryout period between 7 and 30 days is standard for most stores.
  • They occasionally deal with both new and used gear and some very good deals are sometimes available.

Disadvantages:

  • Hifi stores have an extremely high markup, reflecting their small consumer base. All stores have noncompete clauses with neighboring stores in order to protect said customer bases. Therefore, there is often no competition whatsoever in most product lines.
  • Along the same lines, one of the promiment reasons why online stores cannot support certain products as well as hifi stores is that online stores are technically selling outside their 'designated area'. In other words, online support is prohibited because it enroaches on hifi stores' territories. Grado products, in particular, are notoriously bad for online support.
  • Expect to haggle.
  • Hifi stores usually cater to the extremely high end and will often not have much under $500 in the way of turntables.

Mass market stores

Best Buy, Circuit City, etc. They usually have a small selection of retro turntables, and perhaps more if they are ordered to the store beforehand.

Advantages:

  • Cheap (most turntables under $200)
  • Easily accessible

Disadvantages:

  • Very few turntables are sold that are considered any good
  • Very few available accessories and no cartridges
  • 30-day return policy only for support. Hifi stores can actually repair things.

Online stores

Quite a number of online audiophile stores carry turntables of all makes and models.

Advantages:

  • Very inexpensive prices for most turntables
  • Shipping is usually of good quality; the hifi stores are going to get their turntables the same way you would.
  • Widest selection of turntables and accessories.

Disadvantages:

  • Turntable shipping costs are high. Hifi stores will roll in the shipping costs.
  • You may need to pay sales tax.
  • Very little to no support.

Used

There is a huge market for used turntables for any number of reasons. There is a high turnover rate in DJ turntables from people who have attempted to DJ as a hobby. Many people junk their turntables when upgrading their stereos. Audiophiles resell their turntables when upgrading.

Hifi stores sometimes resell turntables or demo units, and it is worth checking them for any deals. They are sometimes competitive.

In general, as a disadvantage, used turntable quality is completely unknown. At the very least you should expect to replace the cartridge and the drive train (belt). At the worst, there may be fundamental structural issues with the turntable, such as a damaged tonearm or bearing or motor, that may not be easily repairable.

Local stores

These include pawn shops and charity stores - Salvation Army, Goodwill, etc. Advantages:

  • Very, very good deals on some items.
  • Inexpensive.
  • Local; needs no shipping.

Disadvantages:

  • Completely unknown quality. Expect to replace the belt if necessary, cartridge, and possibly even the tonearm and wiring.
  • Selection is spotty, and the really good items can get snatched by the store workers.

Online stores and individuals

Notables here include eBay and Audiogon, but also check forums on places like Head-Fi, Audio Asylum, etc for sale posts. Advantages:

  • Large market in turntables of all price ranges.
  • Sellers are often fairly knowledgable.
  • Prices are quite competitive.

Disadvantages:

  • Stores take a rather large cut of the sale price. Audiogon is especially criticized for this. (This isn't a problem with forum interactions.)
  • The risk of shipping damage is quite high. 3rd-party sellers often have very little experience packaging and sending turntables.
  • Risky product quality.
  • No support.


Sources of Distortion

Turntable

Turntable Level

Environmental Noise

Motor Noise

Belt/Drivetrain Wear

Record Wear

Tonearm, Cartridge and Stylus

Tracking Error

Cartridge Alignment

Tonearm Alignment

Cartridge Damage

Stylus Wear

Stylus Damage

Cartridge Distortion

Electromagnetic Interference

Mechanical Resonance

Preamp

Preamp Distortion

Cartridge Loading

Objective Requirements Of Vinyl Playback

These statements are derived from psychoacoustics and electrical constraints that would be necessary to yield objectively optimal playback. These statements also form a concise summary of the audible issues with vinyl.

Pitch, wow and rumble

The playback speed of the turntable must be within 0.3% of 33 1/3 RPM at all times - or 5 cents. Variations of pitch must stay witin the 5-cent requirement and the modulating frequencies must not be audible.

Shockingly, this is extremely hard to achieve in belt-drive turntables for a number of very important reasons. Good direct drives are much better at pitch. (Bad direct drives are much worse at flutter.)

Low rumble

The low frequency noise (rumble) of the turntable must not impinge on program material, must not distort amplifier or speaker stages, and must not be audible.

Rumble is an intrinsic part of both the vinyl medium and the turntable. Often times, 5-10dB of the peak amplitude of a vinyl recording is contained in the rumble, and removing it can help increase the loudness for essentially free.

Frequency response

After RIAA equalization, the system must be able to reproduce frequencies from 20hz to 20khz to within 0.1dB of the source media.

0.1dB is close to the theoretical JND of amplitude for a single sinusoid; tolerances around 1dB in response are usually acceptable.

MM cartridges are well-known for boosting the high end if improperly loaded. Stylus or record wear will eliminate high frequencies. Rumble may make low frequency reproduction difficult.

Stereo Separation

Forum Posts and FAQs

HydrogenAudio threads

  • What sample rate to record with? (thread thread) In general 44.1khz will work fine. There are not significant reasons to choose either 44.1khz or any higher sample rate. Some postprocessing tools for vinyl recordings only operate at 44.1khz. Additionally the dynamic range and distortion specifications for many sound cards are better at 44.1khz than at higher sample rates.
  • What bit depth to record with? (thread) Similar to the sample rate question above. In general 16 bits actually does work well. It's a common misconception that the quantization noise will significantly raise the noise floor of the recording; as long as the signal peak is -10dbFS or higher it is not an issue. If you plan to perform a very large amount of digital processing on the recording, the rounding errors could build up sufficiently that they impinge on the background noise level of the vinyl. In that case the recording should be made at (or converted to) 24 bit resolution prior to the processing stages to reduce the effect of rounding errors. That said, you would need to do a very great deal of processing before a 16 bit recording of vinyl became degraded in this way. A few passes of EQ, noise reduction, amplitude adjustment, etc. isn't going to bring the quantisation noise up above the vinyl noise floor.
  • How low of a frequency can LPs produce? (thread) The common wisdom is that they don't have much below 60hz, but there is evidence that the signal extends as low as 20hz and possibly lower on some LPs. Note that low bass on vinyl records will be mono, but this is not a problem because low bass is non-directional. (The reason for this is that low bass signals cause the largest groove excursions, and of course the vertical (out of phase) component of the groove must never be so great that the groove rises above the surface of the record, so the out of phase component of the low bass is removed when mastering for vinyl).
  • How much bandwidth is on an LP? (thread) This is a hard question, because the dynamic range has to be considered and it is frequency-dependent. It is almost certainly lower than CD, and certainly far lower if the theoretical bandwidth limits of the CD medium are considered, rather than the digital specifications. Although some sort of signal above 20kHz can be recovered from an LP, it is highly unlikely to be related to the programme material; in other words it is noise. The majority of LPs probably contain nothing of significance above about 16kHz.
  • What recording level should LPs be recorded at? (thread) As high as possible without clipping. -3db is usually safe and some sound cards may distort if driven past that. If you are recording on a sound card with a good noise floor (100db or greater) then you can go as low as -18db without ill effects.
  • How to remove sibilance? (thread)
  • How should mono LPs be recorded? (thread)
  • What are some examples of good and bad vinyl rips? (thread thread thread thread)
  • Can/should LPs be ripped faster than real time, ie at 45rpm or 78rpm? (thread) No.

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