Understanding Turntable Basics

Understanding the sources of feedback, distortion and tracking errors will help you to improve your own stereo system. Many of the strategies available to you are very inexpensive to execute. THE HOLY GRAIL of setting up and tweaking your turntable is to make it ACOUSTICALLY DEAD. It is a mechanical pickup system. The job of the cartridge is to translate vibrations into sound. You want it to read only the vibrations caused by the stylus getting moved around by the groove. You don't want to pick up the vibrations in the record itself, or the platter, or the tonearm, or the plinth (deckplate) that it's mounted on. Waves interfere with each other. Waves can cancel each other out. For that reason, when your turntable is exposed to and transmits vibrations from the floor, you'll get more than just feedback and muddiness. Fine details also get washed out. When you have finished a major upgrade or even a small tweak, you'll be able to play records that you're already familiar with, and realize that you're hearing more individual notes than before.

Additionally, bass notes will be much tighter and more clean. Mid-range and high notes become much more distinct. When you've isolated and improved your system to the point that it's really sensitive, you'll hear that each note has a beginning, a middle and an end. And, that's when digital copies of the same music start to sound really bad by comparison. Choosing a Turntable. Direct Drive vs. Belt Drive. Direct drive turntables have the advantage of a quick-start system. You can turn the motor off or hold the platter still with your left hand, put the needle down where you want and quickly get back up to speed. Putting the needle down with the platter sitting still allows greater accuracy and confidfence, and minimizes damage to the record and needle, as well as the harsh noise associated with unstable needle drop. However, to allow quick startup, most direct drive turntables have unusually light platters, allowing greater resonant feedback. They can also transmit more noise from the motor and bearing. Speed can be more unstable, causing greater wow and flutter. A notable exception is the Technics/Panasonic SL1100 and 1200 series turntables. They are particularly heavy, stable and quiet, as direct drive tables go. The SL1200 series is the club DJ's number one choice, and is also perfectly acceptable for audiophile playback (with an "audiophile" cartridge, not a club DJ cartridge). Belt drive turntables, on the other hand, force users to put the needle down with the platter spinning, which requires patience and skill, or a cueing mechanism that drops smoothly. Turntablebasics offers super-viscous silicone fluid for this purpose. Belt drive tables also allow greater platter mass and speed stability. Disadvantages include the propensity of the belt to stretch and harden over the years, hindering both tension and grip. Happily, turntablebasics offers a wide selection of new turntable belts.



Anti-Skate Mechanism. The spinning of the record naturally puts a centripetal force on the stylus, causing the tonearm to want to fly to the inside of the record. This force can cause an imbalance in signal strength between the right and left channels, as well as make groove-skipping more likely. Anti-skate mechanisms come in two styles: those that have a visible assembly of string, pulley and weight that produce a torque on the tonearm shaft that pulls it back to the outside of the record; and those that present only an adjustment knob next to the tonearm base. Some tonearms have no anti-skate mechanism at all. My Grace 714s have no anti-skate, and I have to keep the balance knob leaning toward the right channel to compensate. The heart of the matter: how to properly adjust the mechanism? Some test records have blank bands at 3.5 inches and inward to the inner groove, to calibrate the anti-skate mechanism. The mass of the weight, or the notch on the bar where you attach the weighted string, or the adjustable dial, should be modulated until the tonearm sits still while riding on this blank band, at about 3.4 inches from the center, instead of floating toward the inside or outside. If you don't have a test record with this feature, then use a record with a blank side. One LP that is currently available that has a blank fourth side is Adore by the Smashing Pumpkins.