Turntable Calibration

DJ Kemist brings you a simple guide for the care and calibration of your turntables. With the right care, your professional turntables should last for years. This maintenance is based on the industry standard Technics SL1200 series but is equally applicable to most turntables of a similar genre….
There are three main areas we will look at when calibrating a turntable:

How to level the turntable, pitch, break settings and the tonearm.

To properly level a turntable you will need a circular bubble level. Bubble levels can be found at your local hardware store or on the Internet for a range of prices, but for the most part, for a DJ-type situation, any Spirit level will do. I spent a couple of quid on mine at a local hardware store, and it seems to do the job just fine.

Start by checking how level the work area is. If the surface you’ll be putting your turntable on is not level, do the best you can to make it so. Get your turntable into position, and screw all the feet into the turntable as far as they can go. Do not over tighten them. Take the slipmat off the platter and place the bubble level on the platter, just to the right of the spindle, so that it is roughly in the center of the whole turntable. Use the feet to level the turntable, and then replace the slipmat.

Tonearm calibration is critical for correct playback of records. An improperly calibrated tonearm can result in skipping needles, increased record wear, decreased stylus life, and poor fidelity. Proper tonearm calibration translates into proper stylus performance and allows you to make the most of your turntable and stylus. There are three settings that affect tonearm calibration: weight (tracking force), anti-skate, and height. In order for your stylus to be at its best, all three of these settings must be correct and working in harmony

To properly set the stylus tracking force, the tonearm must be balanced, or zeroed. To balance the tonearm, start by installing the headshell and cartridge. For maximum precision, remove or flip up any stylus guards.

To protect your stylus, place a one-sided record on the turntable black side up. If you don’t have one, place a record on the table that you wouldn’t mind scratching. Unlock the height adjustment and raise the tonearm height so the stylus has clearance above the record to swing free. Twist the counterweight back and unlock the tonearm, the tonearm should rise into the air. Gradually turn the counterweight forward until the tonearm floats above the record.

Step back and look at the tonearm as it floats. The tonearm should be level, or balanced. Return the tonearm to its rest and lock it down. Hold the counterweight in place and turn the weight dial to zero. The tonearm is now zeroed.

To add tracking force, turn the whole weight to the desired setting. Follow your styli’s instruction guide for correct settings. To setup an s-shaped tonearm, the anti-skate settings must be correct. There are two anti-skate calibration settings, relative and absolute anti-skate. Relative anti-skate is set by the anti-skate dial, and absolute anti-skate is set by the concentric screws in the tonearm pivot.

There are two kinds of anti-skate forces, positive and negative anti-skate. A force that pushes the tonearm away from the spindle is a positive anti-skate force, and a force that pulls the tonearm into the spindle is a negative anti-skate force. The anti-skate dial adds positive anti-skate, and is used to counteract an s-shaped tonearm’s natural negative anti-skate that it exhibits when playing.

Ideally, a balanced tonearm should not display any anti-skate forces. To test for absolute anti-skate, unlock and balance the tonearm. Be sure that the anti-skate knob is set to zero. Place the tonearm at the middle point between the spindle and the edge of the platter. The tonearm should remain at rest. Tonearms that pull outward display a positive absolute anti-skate, and tonearms that pull inward display a negative absolute anti-skate.

To calibrate the tonearm so that it displays a neutral absolute anti-skate, the bearing screws need to be adjusted. This is dangerous, as over-tightening the bearing screws will damage the bearing. I would suggest taking your turntable to a qualified turntable technician, but if you want to adjust it yourself, here is how to do it. Return the tonearm to its rest and lock it down. Take a precision screwdriver and unscrew the center screw. The center screw is the top pivot for the tonearm, and the outer screw is a locking screw.

When you have the screws free of the pivot, line up the screws so that the top is flush. Now is a good time to lube the pivot screw. Place a drop of oil on a q-tip and lightly lube the point of the pivot. Line up the bearings (on the tonearm suspension) with hole in the tonearm frame, and hand-tighten the bearing screws. While you are tightening the bearing screws, gently wiggle the tonearm suspension.

Stop tightening when you have eliminated the play in the tonearm suspension. Unlock the tonearm and bring it back to the mid-point between the spindle and the edge of the platter. When you release the tonearm, it may drift out to the edge of the platter. Bring the tonearm back to the mid-point, and gently tighten the center-bearing screw with a precision screwdriver, and then test for anti-skate again. Be careful not to over tighten. Only turn the screw about a degree every time you test the tonearm.

When you have found the correct tightness, the tone arm will stay balanced at about the mid-point. Verify that you did not over tighten the tonearm by moving the tonearm through its range of motion. It should swing freely and smoothly, with no binding. If there is no binding, then you have successfully calibrated your tonearm so that it has neutral absolute anti-skate. Lock the tonearm down and hand tighten the outer locking screw. Double check absolute anti-skate once you have tightened down the locking screw.

For DJ use, such as back cueing and scratching, the anti-skate knob should be set at zero. Positive anti-skate will cause skipping. For hi-fi use, some relative anti-skate should be used to counteract an s-shaped tonearm’s natural negative anti-skate. To set anti-skate for hi-fi use, place a one-sided record blank side up on the turntable. Place the needle on the blank record at the mid-point and gently turn the platter by hand. The needle will slide in towards the spindle. Add positive anti-skate force with the anti-skate knob until the needle stops sliding.

Anti-skate is usually around half the tracking force. (3 grams weight = roughly 1.5 anti-skate.) To calibrate the height of the tone arm, unlock the height ring. Put the needle on a grooved record, and look from the side to see the angle of the tonearm. Ideally the tonearm should be level while playing, or slightly sloped down from the pivot. Having the tonearm slope down helps tracking during scratching. Check with your styli’s instruction guide for a range of height adjustments. Tonearm height can vary greatly due to thickness and type of slipmat.