Playback and Recording (Vinyl)
- 1 Why vinyl?
- 2 Why not vinyl?
- 3 Vinyl Availability
- 4 Playback system
- 5 Turntables
- 5.1 Construction
- 5.2 Prices
- 5.3 Component Availability
- 6 Pickup Cartridges
- 7 Phono Preamplifiers
- 8 HydrogenAudio FAQs
- 9 Links
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.
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.
To play a record, you need the following:
- A turntable, which includes a plinth, platter, motor, and tonearm.
- A cartridge and stylus. Most turntables under $1000 will include a cartridge. Most turntables over that amount won't.
- A phono preamplifier that boosts the electrical signal from the cartridge to line levels suitable for other audio components.
- Supplementary (and optional) accessories, including a record cleaning machine, dry cleaning brush, stylus cleaner, etc.
Turntables vary widely in price, construction and age. Audiophiles will categorize the subjective qualities of a turntable on the following metrics:
The plinth is the base of the turntable, on which the platter (and usually the motor) rests. The basic function is to isolate the components mechanically from the base of the turntable and from each other.
Construction styles vary:
- No isolation whatsoever (solid box). For very cheap turntables.
- A box, often wooden, holding a metal plinth supported by springs. Usually found only on vintage turntables.
- A plinth of multiple levels, each level isolated from the other by some rubber-like substance. In some form or another most audiophile turntables use this method.
- Physical separation of the turntable components from each other, and individual isolation of each component from the ground. Certain very expensive turntables use this method.
There are few objective criteria for plinth design. Isolation issues can be resolved through the use of additional isolation placed underneath the turntable. Build quality is important and may be lacking, even for audiophile turntables.
The stick-shaped part of the turntable.
- They hold the cartridge on top of the record, keeping it properly aligned, and carry the wires down to the plinth.
- A counterweight is placed on the back to reduce the force of the needle on the record to very low levels, usually equivalent to an effective mass of roughly one gram.
- A force, the anti-skate force, is applied to the tonearm, pulling it outwards from the center of the disk, to counteract forces during playback that pull it towards the center.
- The tonearm must be lowered slowly onto the disk to prevent damage to the disk or the stylus. All quality turntables include a mechanism, usually hydraulic, to slowly lower the tonearm.
Key differences between tonearms include:
- Build material
- Shape (S-shaped or straight)
- Linear tracking or angular tracking
- Degrees of freedom on the mounting
- Antiskate force mechanism
There are several objective differences between tonearms:
- The mass of the tonearm affects the resonances of the playback system. The mass can sometimes be incompatible with the mass of the cartridge and the compliance of the stylus, leading to an excessively high or low resonant frequency that induces skipping or rumble, or can negatively affect low frequency performance.
- Tracking errors, representing angular deviations between the stylus and the record groove, are present with every tonearm, and different designs use different approaches. Linear tracking arms, in theory, have zero tracking error. In practice they require a motor to move the tonearm, with some known error in correct positioning, as well as some vibration. S-shaped tonearms are shaped to reduce tracking error but (XXXX list issues).
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- Counterweight markers are notoriously unreliable and a scale is often employed to get a correct measurement of the counterweight setting.
The platter is the rotating part which supports the vinyl record while it is played. The platter should ideally be acoustically dead, ie. it should not "ring" like a bell. Platters that ring store energy and release it slowly back into the record, causing loss of fine detail.
Belt drive turntables use a small motor turning fairly rapidly, and a belt then transfers the power from the motor spindle to the platter. On some models the motor sits outside the platter and the belt runs around the outer edge of the platter; on others the platter is in two parts with an inner spigot for the belt, with the motor sitting between the spigot and outer edge of the platter. There is no significant advantage to either arrangement, with the possible exception that when the motor is external to the platter it can be sited a long way from the path of the pickup cartridge, and therefore potentially reduce the danger of hum pickup by the cartridge from the motor.
The belt (usually some form of rubber or similar material) provides excellent decoupling so that motor bearing noise is not transferred into the platter (and thence to the LP).
The motors used are usually synchronous AC motors whose speed is determined by the frequency of the mains supply. Some more expensive belt drive turntables include a sophisticated power supply which generates an AC signal even cleaner than that provided by the mains.
Since the motors on belt drive turntables do not have much torque, and because the AC frequency might vary slightly, stable rotation of the platter is achieved by the use of high mass platters that provide a "flywheel" effect to smooth out any variations. A consequence of using a high mass platter and a low torque motor is that start-up speeds are rather slow, and hence belt drive turntables are not really suitable for broadcast or DJ use.
In a direct drive turntable, the central spindle in the platter is an extension of the axle. So the motor itself sits directly underneath the platter, and rotates slowly at the required vinyl record playback speed (ie. 33.3/45/78 rpm). Such motors are servo-controlled DC motors, and the turntable includes some means of measuring the rotation speed of the platter so that it can adjust the motor's speed to keep it steady. In order that any speed inaccuracies can be adjusted quickly enough, the motor must have high-torque; this also means that startup speeds are very rapid, hence the preference for direct drive in broadcast and DJ applications.
Since the platter is directly attached to the motor, it is not well decoupled from any bearing noise. However, since the motor turns at a slow speed, the bearing noise is very low frequency and therefore will not cause audible degradation.
Idler Wheel Drive
This type of drive mechanism was traditionally used on cheap autochangers, and involves a small motor running at fairly high speed (like in a belt drive turntable). But unlike a belt drive turntable, the power is transferred to the platter by means of a wheel (usually rubber) sitting between the motor spindle and the platter edge. The wheel offers far less decoupling, and so motor noise is transferred to the platter. What's more, because the motor rotates at high speed, this noise can affect the audible frequency spectrum.
That said, there have historically been some successful high quality idler wheel drive turntables. Perhaps the most famous is the Garrard 301.
Internal Wiring and Power
The cartridge electrical system is entirely passive; no power is required for the electrical signal to be sent to the preamp. The signal output may be vulnerable to electrical interference because of the high impedance of the cartridge and the long length of wire to the preamp. The motor usually receives the AC wall power directly and converts to its own required power internally. Some higher end turntables use external power supplies.
Power wiring can be a cause of increased interference with interconnects, so try to keep power cables separate from other cables. If they must cross, cross them at 90 degree angles.
All prices are for new turntables. The used market is highly irregular but you can usually expect a 20-50% discount. All prices are sampled from online vendors and may not be realistic for purchase at local stores.
- $200 or less: Inexpensive belt-drive or direct drive turntables. You'll find turntables in this price range at Best Buy/Circuit City with vintage stylings. Because these are the mass-market items, these will quite often have features like automatic loading, 78rpm operation, and strobe marks that are absent from more expensive turntables. Many of them have integrated preamps. The quality of these turntables is highly variable, and because most audiophiles do not spend much time in this range, experience is hard to find.
- $400 or less: Entry level audiophile/DJ turntables, and used mid-range turntables. Most $200-$400 turntables have related models that cost under $200 so they are grouped together here. Brands in this price range include Audio Technica, Technics, Teac, Numark, Stanton, Music Hall, Pro-Ject.
- $400-$1000: Most introductory-level audiophile turntables are at this price, as well as flagship DJ turntables such as the Technics SL1200. Other brands with models in this range include most of the brands in the $400 range and also Rega, Thorens, Sota and Goldring.
- $1000-$10000: The meat of the audiophile market. Most high-end turntables will be somewhere in this range. Most brands have something here, but brands that operate exclusively in this price range include Clearaudio, Bluenote, JA Mitchell, Origin, Roksan and SME.
- Over $10000: Esoteric audiophile models, including audiophile linear trackers and laser pickups.
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.
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.
- Most hifi stores are locally owned and operated.
- There are nontrivial transportation issues with turntables, being fragile mechanical devices, and it really helps to have a distributor take care of the dirty work of receiving and testing the turntable.
- 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.
- 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.
- 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. Expect to haggle.
- 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.
- 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.
- Cheap (most turntables under $200)
- Easily accessible
- 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.
Quite a number of online audiophile stores carry turntables of all makes and models.
- 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.
- 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.
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.
These include pawn shops and charity stores - Salvation Army, Goodwill, etc. Advantages:
- Very, very good deals on some items.
- Local; needs no shipping.
- 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.
Notables here include eBay and Audiogon. Advantages:
- Large market in turntables of all price ranges.
- Sellers are often fairly knowledgable.
- Prices are quite competitive.
- Stores take a rather large cut of the sale price. Audiogon is especially criticized for this.
- The risk of shipping damage is quite high. 3rd-party sellers often have very little experience packaging and sending turntables.
Direct online sales
Many online forums have for-sale sections. These include Audio Asylum and Head-Fi. This basically works exactly like buying from the online stores listed above, except there's no cut of the sale to the web site.
- Very low cost.
The pickup cartridge is the device mounted at the end of the tonearm which holds the stylus (usually diamond) onto the record's groove. The groove vibrates the stylus, which transfers this movement into the body of the cartridge via a short rod (known as the "cantilever"). The cartridge then has the task of converting the mechanical vibration into an electrical signal. Different types of cartridge use different methods to generate the electrical signal.
The vast majority of cartridges use electromagnetic induction to generate the signal (and are therefore known as "magnetic cartridges"). This method involves moving a permanent magnet and a coil of wire (a pair of coils for stereo) relative to one another.
Most magnetic cartridges are of the type known as "moving magnet". As the name implies, in this type the coils of wire are fixed, and the magnet is moved relative to them. There are some advantages to this type:
- Since there is no physical connection between the sylus and the wiring, the stylus can easily be made replaceable.
- Since the coils of wire are fixed, they can use a large number of turns, thereby increasing the output level from the cartridge (typically around 5mV), which will then require less subsequent amplification and hence lower noise.
The large number of turns on the coils give moving magnet cartridges a high output impedance (typically 47kOhm). This requires that the loading at the amplifier be carefully matched to avoid high frequency losses. Fortunately pretty much all phono inputs on amplifiers have been standardised at 47kOhm.
Moving magnet cartridges also typically have a mechanical resonance in the upper treble (above 10kHz) leading to a rising frequency response. This is compensated for by the use of a small amount of capacitance (typically between 100pF-500pF, depending on the cartridge) at the input. This capacitance shunts some of the high frequency signal to ground.
In a moving coil cartridge, the magnet is fixed and the coils are wound onto arms at the far end of the cantilever. Therefore the stylus cause the coils to move relative to the magnet. At first sight, this construction would appear to have a number of disadvantages:
- Since the coils must be moved, they must also be very light and hence can only have a few turns of wire. This is turn leads to very low output levels (typically less than 1mV) and the need for additional subsequent amplification, and thus greater noise.
- Since the internal wiring is physically connected to the stylus, the stylus is not user-replaceable. (A very few moving coil cartridges have been made with a replaceable stylus, but they were not generally successful designs).
Despite these disadvantages, as a general rule moving coil types yield higher fidelity than moving magnet types.
The small number of turns on the coils results in a very low output impedance (typically under 50 Ohms). This means that the amplifier input must also be very low impedance (typically 300 Ohms or less) to prevent serious loss of signal level. The difference between moving coil and moving magnet inputs is not therefore limited to the amount of amplification they provide: the input impedance is critical to achieving an accurate and efficient transfer of the signal from cartridge to amplifier.
Crystal and Ceramic Cartridges
These types of cartridge use the piezo-electric effect. The vibrations of the stylus are used to apply pressure on a crystal or block of material which has a piezo effect, which generates a voltage. The generated voltage can be quite high (up to 100mV, which is enough to directly drive a line level input). However, the accuracy of the voltage generation is typically rather poor, so these types of cartridge are rarely seen nowadays.
Other Types of Cartridge
Grado, a pioneer cartridge manufacturer that was the primary innovator of Moving-Magnet cartridges, calls their technology "Moving Iron". It is occasionally seen in other brands.
From the forums.
- 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.
- http://www.delback.co.uk/lp-cdr.htm cliveb's excellent guide to recording LPs to computer. Includes discussion on cleaning, sound cards, recording, and postprocessing.
- Wikipedia articles on the:
- The Vinyl Engine: Detailed discussion on all aspects of vinyl playback and maintenance. Check out the Library section for good articles and free protractors.
- The Vinyl Asylum at the Audio Asylum: true to its name, this has more voodoo audiophiledom than perhaps anywhere else on the Internet. But there are many good discussions, as long as you take some hefty grains of salt.
- Stereophile forums: Almost as much voodoo audiophiledom as Audio Asylum.
- Turntables & Tape forum at AudioKarma.org
- Head-Fi: Discussions on turntables under the "Dedicated Source Components" forum and the TTVJ forum.
- Steve Hoffman Forums: Excellent technical discussions.