Though rivaled by audiocassettes and the compact disc, the phonograph, invented by Thomas Edison in 1877, endures. The format has evolved considerably from wax cylinders to vinyl records, which have been around since the mid-1950s. Thanks to many large record collections, vinyl remains a viable source for recorded music.

For one thing, many recordings are available only on vinyl. And some audiophiles believe a good recording on vinyl, played on a top-notch turntable, sounds warmer and more live than a similar recording on CD.

The phonograph has three major components: a platter attached to a motor, a tonearm and a stylus cartridge. The spinning platter is what gives the component its name of turntable. Most turntable platters are 12 inches in diameter, the size of a normal record album.

The stylus, the tiny diamond needle, is the primary part of a small electronics package called a cartridge. The cartridge contains connecting wires that send the sound signal picked up by the stylus up the tonearm, which suspends the cartridge over the record, to the output cables in the back of the turntable.

Features

Turntables offer a number of features, the most common of which is variable speed. The 12-inch album is played back at 33-1/3 revolutions per minute (RPM). The seven-inch "single" plays back at 45 rpm. All turntables can play at either speed. Singles (45s) require that an adapter be placed on the spindle to compensate for the larger center hole. All turntables include the adapter.

Most turntables have a fixed speed that must be set at either 33-1/3 or 45 rpm.

The tonearm has two features at either end: the counterweight and the cartridge. People often confuse the stylus and the cartridge. The stylus is the needle and it fits within the cartridge. The stylus has to be matched with a particular make and model of cartridge. Often only a stylus needs replacement rather than an entire cartridge.

For a phonograph to play a record, the needle must trace the course of the grooves gently. If it presses too hard, it can damage the grooves. If it doesn't bear down enough, it will skip in and out of the groove. Because cartridges vary in weight, the counterweight correctly adjusts the amount of pressure on the stylus. A more exact adjustment can be made by using the anti-skating knob at the base of the tonearm mount.

Variations

Turntables come in four models:

• Manual models require you to place the tonearm on the record and take it off when you've finished listening.
• Semi-automatic models require you to place the tonearm on the record, then the unit will automatically lift the tonearm off the record when it finishes playing and then stop the platter from rotating.
• Fully automatic models place the needle on the record and lift it off when the record is over.
• Component models are bought separately and assembled. The motor base, the platter, the tonearm and the cartridge may all be from different manufacturers. Component turntables can cost many thousands of dollars once all the pieces are assembled. Component turntables are popular, as vinyl records become increasingly rare. Many are produced as purely audiophile products.

Manual and semi-automatic turntables are often preferable as many record owners don't trust the clunky automatic mechanism to gently drop a diamond needle on what are becoming valuable and irreplaceable recordings. Most of us can place the needle far more carefully than an automatic turntable can.

As for having to lift the needle off at the end, there are many recordings whose final grooves (The Beatles' Sgt. Pepper album, for example) contain additional music or sounds. A semi-automatic or fully automatic turntable often lifts the tonearm before these grooves are played.

Another difference between turntables involves the motor and how it turns the platter. In a belt-driven turntable, the spindle in the base of the turntable is connected to the motor by a rubber belt, much like the belts in your car's engine. In a direct-drive turntable, the center spindle is attached directly to the motor that spins it. While a direct connection spins the platter at a more consistent speed, the proximity of a direct-drive motor to the platter may add unwanted vibration and noise that can be transmitted along the stylus, tonearm and, ultimately, to the speaker.

Connections

Most turntables have interconnect cables already attached to the base and need only be plugged into the appropriate input jacks of your amplifier. That small thin wire attached to the back of the turntable is the ground wire and must be attached to the ground (GND) terminal located near the phono input jacks on your receiver.

The cartridge connects first to the head shell, a detachable piece at the front end of the tonearm, via two small screws. Be sure the angle of the cartridge matches the angle of the tonearm so the stylus tracks at the correct angle. The cartridge connects to the wires in the tonearm with four small wires of its own, color-coded blue, red, white and green.

The dust you wipe away from your needle may not be just dirt. Your needle is a diamond, and the record is soft vinyl. When you play a record, the needle scrapes the groove, shredding it. The more pressure on the needle, the more it will shred the record. Each time you play a record, you lose a piece of it forever, and eventually, records wear out.

The stylus tip can exert more than 50,000 pounds of pressure on record grooves and can quickly damage the record if it is not tracking properly. The counterbalance and anti-skate knob must be adjusted exactly. When you adjust the counterweight and the anti-skate knob on your turntable, keep the pressure exerted on the cartridge and needle as light as possible to keep the scraping to a minimum, but make it heavy enough to keep the record from skipping.

Accessories
The primary accessories for turntables are adapters that fit over the spindle for playing 45-RPM records and brushes that fit over the end of the cartridge to clear record grooves of excess dirt and dust.

The problem with this brush is that it can upset the delicate balance of the tonearm. Even though the weight of the brush can be taken into account by adjusting the counterbalance and the anti-skate knob, the extra weight was not taken into account by the designers of the cartridge, stylus or tonearm. This may mean that if you've attached an accessory brush to the head shell, the stylus may not track according to specifications. Some cartridge makers incorporate a brush, which solves the problem.

Maintenance

Vinyl records are probably the most fragile recording medium. They are susceptible to many dangers, including just being played, because you are running a hard diamond through soft, warm vinyl.

Keep your records away from heat. Records left on a turntable in direct sunlight will warp quickly.

Store your vinyl records upright, not leaning, or stack them flat in piles of no more than 15, in their sleeves.

When you buy a new album, remove the outside plastic wrapping. That wrapping can shrink enough to warp a record left in a warm place.

Use a commercial record cleaner before each play to remove any dirt on the record.

Clip the tonearm to its support when you finish playing a record. When the tonearm is balanced, it is light and will skip around at even a slight nudge. This is especially important when you move your turntable.

Keep the cover down. Dust can settle on the platter, of course, but it's worse if it settles on the stylus.

Today's diamond stylus needs to be replaced after 400 to 600 hours of play. To replace it, take the model number (or the stylus itself after you carefully remove it from the cartridge) to the dealer authorized to service your turntable.

The cartridge links your phonograph to the rest of your stereo system. If it is more than five years old, replace it to ensure good sound and longer life for your valuable records.

In fact, if you're buying a new turntable or replacing your stylus or cartridge, buy more than one stylus and cartridge. You may not be able to find the one you want in a few years.