turntable

SP10 Plinth System

Anatase

For most of the 20th Century, if you listened to recorded music, you were listening to a record. All the innovations following analog records, digital medium like CD's and now music as downloads, have not been an improvement, judging by quality of sound. For those who care what music sounds like, records are still the ultimate way to listen to recorded music. And despite the music and hifi industry's concerted attempts to kill off analog, record sales are increasing exponentially every year. Besides new music released on vinyl, there is a torrent of newly reissued albums in all genres. So if you want to really listen to music as a physical thing, you'll be playing a record. Problem is, it's not so easy finding a great record player today.

Back when every home stereo had a record player, the best ones were all "idler drive." Professional machines used in broadcast, radio and studios were often "direct drive", but these were too expensive for consumers. There is also a third type of drive for turntables, which is known as "belt drive." Belt drive came about because it was much cheaper than the alternatives. Today, virtually all turntables are belt drive, again because the profit margins are so much higher, and the engineering bar so much lower, than for idler or direct drive. The market for turntables today is obviously tiny compared to the heyday of vinyl. In the golden age of vinyl from the 1950's-1970's, companies like Garrard in Great Britain, Thorens in Germany, and Lenco in Switzerland, produced hundreds of thousands of extremely high quality idler turntables for the high end of the mass market. Most audiophiles today have never heard these decks, but for decades an underground of dedicated music lovers, mainly in Japan and Asia, have been using these turntables instead of high end modern belt drive ones.

Drive Mechanisms, and Why They Matter

A turntable appears to be a rather simple device. A platter must spin at 33.3rpm (and maybe 45 and 78 rpm) quietly and consistently. In reality, this is an incredibly difficult feat. Record grooves hold an enormous amount of information, and our hearing will pick up unbelievably tiny changes and errors in speed. Although the mechanism of a minuscule diamond stylus tracking modulations in a record groove looks easy, as the music becomes more complex and louder, the grooves in the record present a much rougher road, and the stylus puts more drag on the rotating platter. This will slow the record down. The result is blunted transients, dynamics suffers, and music no longer has the proper flow and ease. This type of distortion in the domain of timing with record players is virtually impossible to measure, and thus easy for the audio industry to ignore. It is very easy to hear, though, especially if you can compare an idler drive turntable or direct drive turntable with a belt drive turntable.

Idler drive refers to the rubber idler wheel, usually 2-3 inches in diameter, which transfers the rotation of a motor's shaft to the edge of the platter. The wheel serves several purposes: it has a mechanical advantage which increases the power of the motor, it acts to isolate motor vibrations from entering the platter and the music, and it provides very assertive control of the platter by the turntable motor. These motors were always substantial in power and size, their speed governed by the frequency of electricity, and thus idler motors had no feedback loop controls. Such motors are no longer made, which explains why no company currently makes a new idler drive turntable.

Direct drive tables of the highest quality were really used only in professional applications, as they were extremely expensive. At the end of the vinyl period, Japanese companies made many consumer direct drive turntables, which were a trickle down from engineering developed for the professional models, and because there was still a huge market. Most of those consumer tables were very inexpensive and not very good. Today only a handful of companies make (expensive) direct drive turntables.

Belt drive is the simplest drive from an engineering and manufacturing standpoint. Place a little motor at some distance from the platter, connect them with a belt, thread or tape, and you have a turntable. This system accounts for almost all turntables made today. A much smaller, cheaper motor can be used than in the other systems, usually compensated by a very large platter to provide inertia (flywheel effect.) The belt helps isolate any motor noise from the platter. The problem is that all belts slip. They do not have good coupling to the platter, and speed errors result.