A compact disc (CD) player is a primary music source component for most audiophiles, along with an AM/FM tuner and, perhaps, a turntable. The CD player feeds its signal to the pre-amplifier, integrated amplifier or receiver, depending on the amplification system in use. Most modern control amplifier components have a "CD" position among the Phono, Tuner and Aux options available for selection. If not, the Aux position will work fine, as the output from a CD player is a high level (about two volts) source. CD, Tape, Tuner and Aux are all high-level sources and interchangeable. You can plug your CD player into any of these unused input jacks on the amp's rear panel. Incidentally, "Phono" is a low-level source and a CD player should NOT be plugged into the phono input jacks.

Most audio CD's are recorded to the "Red Book" standard, written by Sony and Phillips in 1980, when the CD format was introduced. Some audiophile recordings are SA-CD (Super Audio Compact Disc) format, which requires an SA-CD player to achieve the full increase in fidelity offered by these recordings. All SA-CD players also play standard Red Book CD's and most SA-CD recordings will play to the Red Book standard on a conventional CD player. SA-CD players are offered by Marantz, McIntosh, Luxman, Yamaha, NAD, Denon and others. SA-CD has not, so far, caught on with the general public and its future is uncertain at this writing. It may gain traction, remain an audiophile specialty format or disappear altogether. Only time will tell. Certainly, SA-CD has not made standard CD players obsolete; indeed, standard Red Book CD players remain the majority in the market place.

The digital compact disc and CD player represented an enormous advance over the long-playing (33-1/3 RPM) vinyl record and its associated turntable. It also made the high fidelity cassette tape and its associated play/record deck obsolete. The CD is a very high fidelity sound source with an incredible signal to noise ratio, great dynamic range, extreme channel separation and flat 20-20,000 Hz frequency response. There is no hiss, rumble, wow or flutter when playing back a CD. CD's are not indestructible. In particular, their playing surface can be scratched, but they are far more durable and last much longer than vinyl records and tapes. Down-loadable music forms, particularly MP3, are compressed and cannot equal the high fidelity of CD's.

To take advantage of the inherent fidelity of the compact disc, a component player must be sophisticated and well made. As with most high tech products, these qualities increase the price. A cheap CD player can offer decent sound, but it will not be the best sound and its physical construction, particularly its CD drawer and transport system, will be flimsy. Inexpensive players have less sophisticated power supplies, digital to analog converters (DAC), timing clocks, error correction and inferior shielding against stray electrical interference. For all these reasons, upscale CD players sound better and have a much longer service life. Indeed, I used the same 1986-vintage Sony CDP-620ES (ES was said to stand for "expensive Sony") for 25 years. Sony no longer offers machines of that quality, but that player paid for itself many times over and still sounds good.

CD players can be single play units, carousel changers (usually with five disc capacity), or loaded with high capacity CD "magazines." The carousel type, usually medium priced, are probably the most popular, while single play units run the gamut from cheap to ultra-expensive audiophile players in the five-figure price class.

Like other stereo components, CD and SA-CD players have specifications that are worth noting. Brands and models that are not accompanied by a spec sheet should be avoided on general principles. (What is the manufacturer hiding?) Here are the specifications for a reasonably typical, mid-priced CD player, in this case a Yamaha CD-C600, a five-disc changer that carries a moderate 2011 MSRP of $379.95

Frequency Response CD	2 Hz–20 kHz± 0.5 dB
Harmonic Distortion + Noise CD	0.003%
Signal-to-Noise Ratio CD	105 dB
Dynamic Range CD	96 dB
Output Level CD (1 kHz, O dB)	2 ± 0.3 V
Dimensions (W x H x D)	17-1/8" x 4-5/8" x 16"
Weight	13.7 lbs.

Note the excellent (compared to an analog or portable digital music source) 105 dB signal to noise ratio, 96 dB dynamic range and 2-20,000 Hz frequency response +/- 0.5 dB. Also, note the unit's 13.7 pound weight. These are typical specifications for a component CD player, whether single play or carousel, in this price class.

For comparison, here are the specifications for Yamaha's top of the line CD-S2000, a single play SA-CD/CD player with a 2011 MSRP of $2499.95.

Disc Compatibility		SA-CD, CD, CD-R/RW (MP3, WMA)
Frequency Response	CD	2 Hz--20 kHz
	Super Audio CD	2 Hz--50 kHz -3dB
Harmonic Distortion	CD (1 kHz)	0.00002
	Super Audio CD	(1 kHz) 0.0017%
Signal-to-Noise Ratio	CD/Super Audio CD	116 dB
Dynamic Range	CD	100 dB
	Super Audio CD	110 dB
Output Level	CD/Super Audio CD (1 kHz, O dB)	2 ±0.3 V
Dimensions	(W x H x D)	435 x 137 x 440 mm; 17-1/8” x 5-5/16” x 17-5/16”
Weight		15 kg; 33 lbs.

These specifications are even better and the CD-S2000 plays both standard CD and SA-CD discs. However, the biggest difference is the CD-S2000's 33 pound weight, over twice that of the CD-C600. This indicates a superior transport, power supply, shielding and overall construction. I have no personal experience with the CD-S2000, but I would guess it is built to last. The lesson here is that the biggest difference in the price of CD players may not be glaringly obvious from their electrical specifications. A close physical examination of different CD players can be revealing.

Upscale units will usually track better than less expensive models. Tap or rap the case while the unit is playing to check for this. Of course, critical listening is the final test. All CD players do not sound alike. Listen for the model that most accurately reproduces music with which you are familiar. (Take a few of your own CD's along when you audition CD players.)

In addition to CD and SA-CD players, there are components that can play DVD video discs in addition to audio CD's. Like standard (audio only) CD players, these audio/visual components vary in both price and quality. They are convenient for use in home theater systems and high quality units, such as the McIntosh MVP871, are also found in high quality two-channel music systems. The MVP871 can play standard compact discs (CD, CD-DA, video CD), SA-CD's, DVD Audio/Video, HD-CD and MP3, all with very high levels of fidelity. As you would expect with a McIntosh product, it is well made and beautifully finished. All of this does not come cheap; the MVP871's MSRP is a hefty $5000.

Most CD players come with a remote control that allows you to select Play, Pause, Stop, Fast Forward, Fast Reverse, Next/Previous track, Single track, Repeat, Continuous Play and Shuffle Play from your listening position. There is usually a numerical key pad on the remote that allows you to select any track by number and often a volume control.

On the front panel of most CD players is an On/Off power switch, a button that opens and closes the CD drawer and some or all of the controls duplicated on the unit's remote control. On the back panel is, at least, the AC power cord and stereo Left/Right output jacks that allow you to connect the CD player to your pre-amplifier, integrated amplifier or receiver. These usually accept patch cords with coaxial RCA plugs. Hook-up is fast and simple.

Most of us have accumulated a considerable number of audio compact discs since the format's introduction and we need a good CD player to enjoy this music library. As with all stereo components, in the end it pays to buy the best CD player you can afford. Look for (1) performance specifications comparable to other players in your price range, (2) a player you like the sound of, and (3) the best built unit. Less important features, such as remote control convenience, can be used as tiebreakers.