The Turntable System: An Overview

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The table system, as its older name declares, is quite literally a phonograph, and the “graph” (writing) it reads is the “phono” (sound) that’s engraved in the record. That’s why turntables and, by extension, all other music sources are also known as transcription sources. The entire raison d’être of the table system is to follow exactly and extract this very delicate, complex line of musical information embedded in the record groove.

One of our central themes is that playback is the mirror image of the recording process—it “unrecords” the recording. The turntable system is the playback counterpart of the cutting lathe. It is in effect an “uncutting lathe” and the direct counterpart to the mammoth lathe that inscribed the music into the lacquer at the mastering lab. To retrieve the most music, the playback cartridge (which in our mirror-image analogy is the unrecording counterpart to the cutting head of the lathe) must very accurately retrace the grooves. The more accurately you retrace the groove, the more music you retrieve and the more wonderful the musical illusion. As you deviate from perfect accuracy, you get increasingly distorted sound, less music, and less of a thrill. Now that’s a very good test—if your music doesn’t keep on thrilling you, there’s something drastically wrong with your system. J. Gordon Holt, founder of Stereophile magazine, calls it the goosebump test.

Ultimately, the entire focus of any turntable system is on the tiny momentary point in space and time where stylus and groove wall meet, often termed the stylus/groove-wall interface. How accurately this minute contact point is maintained determines how well the stylus reads the groove—and therefore how much music you get.

How successfully the stylus/groove interface is maintained is determined at least as much by the table and tonearm as by the cartridge. It’s very easy to mistakenly focus on the cartridge as the nucleus of the turntable system—after all, that’s where the music is “unwritten” from the record groove and converted into that electrical mystery which travels through the system to come out of the speakers as music (or noise, as the case may be).

But you just cannot take a low-quality table and arm and improve their performance by sticking on a superior-quality cartridge. On the other hand, a truly high-quality, well-set-up table and arm will tolerate all but the crummiest cartridges and still deliver good sound. (though obviously the system would be better off with a good cartridge). Besides wasting your money by putting a good cartridge on a mass-fi arm and table, you will actually get worse sound because the better cartridge will expose the poverty of table and arm. You might at first be fooled into thinking you’re hearing an improvement (there even may be improvement in certain restricted areas). But if you listen attentively, you’ll soon recognize that what you’re hearing is a change rather, than an over all musical advance.

What it comes down to is that the table, tonearm, and cartridge must be understood as being inseparable parts of a single system. The performance of any one part directly influences the other parts. To pick up good sound from the tiny intersection of groove and stylus, the table system (and its owner) must strive to accomplish three things success fully: (1) turn the record at precisely the correct speed, (2) rigidly hold the cartridge in correct relation to the groove, and (3) shield the stylus from any extraneous acoustic and mechanical vibrations. All this may sound simple enough, but it remains a very challenging combination of applied physics and aesthetics, something mass-fi table companies try to sidestep neatly—or, worse, aren’t even adequately aware of.

Compare the minuscule scale of the music signal with the scale of the vibrations in your environment coming from airborne and mechanical sources. We’re not talking about gross vibrations like footsteps so much as the commonly ignored micro-sonic environmental vibrations that travel up your turntable support and into the platter, or that stem from the motor, the platter bearing, even the microsonic noise of the stylus tracking the groove. These are as loud as or louder than many of the musical “vibrations” pressed into the groove and so fog the music, especially quiet passages and low-level detail. With groove modulations as small as a wavelength of light, spurious movements of even a millionth of an inch can veil, distort, or even blot out musical nuances.

As laughably insignificant as these tiny contaminating vibrations— from an elevator, passing traffic, the fridge, or an air conditioner—may seem from a human perspective, on the scale of the stylus and groove they are serious forces to be reckoned with. The stylus is as undiscriminating as a little seismic sensor.

The whole table system is, in effect, a delicate seismometer that registers every tremor, regardless of its size or source. But while a conventional seismograph is designed to detect all the minute vibrations in its environment, a turntable must exclude some and pick up just those pressed into the surface of the record.

Obviously, a stylus cannot “know” the difference between musical vibrations intentionally inscribed in the groove and foreign vibrations from the environment. Once spurious information becomes enmeshed with the music, there is no way to remove it. ALL vibrations, whether intentional or not, are automatically picked up and converted by the cartridge into an electronic signal that will eventually be amplified some thirty thousand times. In this sense, the table, and indeed the entire system, is like a microscope—magnifying mechanical energy from the ultra-minute to the human scale.

The upshot is that, on a less than good table that permits vibrations to interfere with “unrecording” the music, what you hear sounds much less like real music and much more like a car radio—canned sound. Good turntables have what is sometimes described as “pulled-apart” sound, where each individual instrument clearly communicates its own discrete acoustic and spatial identity. The layers of sonic grunge imparted by a mediocre table system obscure the so-important subtle in formation, resulting in a collapsing and compacting of the sound. What we’re talking about here is the difference between a beguiling illusion that draws you in, holds your attention, and involves you, and a system that, while it may sound imposing or even impressive, never transports you to the music.

On a really good system, you can identify individual instruments and their specific locations from side to side and front to back—as in the live performance. This becomes particularly striking on good sym phonic recordings, where the string sections finally stop being just a smear of violins, a blur of cellos, and so on. Instead of listening to the audio equipment, you are at last listening through to the musical event. This is why Stereophile and The Absolute Sound magazines consistently stress “transparency”—you start hearing past the equipment into the music. You want your equipment to be seen but not heard!

Incidentally, extraneous noises on some recordings, such as tape hiss or mild surface noise, which are superimposed over and sonically separate from the music, should be of far less concern than the crucial musical nuances blotted out by distortion. One’s musical ear easily learns to ignore tape hiss (like conversation and clinking glasses during a club act—if you don’t remember what this is like as a background to the music, listen to Jazz at the Pawn Shop on Proprius LP7778-79.). But fine musical detail obscured by distortion is music lost.

This assumes, of course, that you’re listening on a good table. On a mass-market table unable to reveal such subtleties, it’s hard to get past the surface noise and other obvious grunge—that’s why folks get duped into thinking that the CD is ipso facto better than the LP.

Any mass-fi ‘table system—even the pricey impress-your-neighbors type—is so unmusical and noisy that the richness of musical subtleties we’re talking about is never heard. Getting good sound from a mass-fi table is like trying to learn about French food by sampling the wonders of “gourmet” frozen dinners.

Next: TURNTABLES: THE BASICS OF GOOD DESIGN: Introduction

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Updated: Friday, 2016-05-13 19:11 PST