BACK ONE Preserving the Sounds
of a Lifetime
Lil' Kaboosa says, Let's play it!
   With vinyl playback enjoying a renaissance, sources of information about turntables, and getting the best from them, are difficult to find. We hope you find these sections informative.

Turntable Setup

   Most turntable companies provide reasonably good instructions for the proper setup and operation of their products. But sometimes, these instructions are not very clear, or are translated in a peculiar way. Hopefully, this section will remedy some of the questions that come up during turntable setup

The Platter

Direct Drive
   For direct drive turntables, place the platter over the spindle and lower into place gently. There is usually a strong magnetic force that will pull the platter into place. Be prepared for that and lower the platter gently into position on the spindle. Now. place the mat on top and this step is complete.

Belt Drive
   There are 2 kinds of belt drive. dual platter designs and single platter designs. In the dual platter design the 2 parts are the drive or inner platter and the top platter. The drive platter is permanently part of the turntable body. The drive belt runs around this platter and the motor pulley. Install it now if required. Now place the top platter in position, then the top mat and this step is complete.
   In a single platter design, there must be a way to contain the belt when installing the platter. If you look under the platter, you will see an inner ring running around the middle third of the platter. The belt should be already installed by the factory there. If not, do it now. The belt will stretch and stay in place. Now, place the platter over the spindle. You should notice a hole in the the top platter. Align this hole over the motor spindle. Now, reach in and pull the belt across to the motor pulley. Now place the top mat and this step is complete.

Cartridge Mounting

Standard Mount Style
   Some turntables come with the cartridge already mounted. This makes life easy. But if you are changing the cartridge or simply need to mount it, here are the details.
You will need:
  • Small screw driver
  • Small needle nose pliers
  • Overhang Gauge
  • Cartridge Hardware
  • Contact Enhancer (optional)
  • Tonearm Headshell (if separate)
   I will use the procedure we follow here for Stanton cartridges and Technics Head shells, the process is basically the same for other tonearm designs.
Use the self threading plastic slip on nuts, they prevent electrical grounding of the cartridge body to the headshell. This can be a major cause of ground loop hum. Slip the nuts onto the cartridge mounting flange wings.

   Now, hold the cartridge in place against the bottom of the head shell and insert a screw through the top of the head shell and into the self threading nut. Use the screwdriver to start this screw. Once started, insert a screw in the remaining side and start it too. Snug each screw into place a little at a time, until they are just almost home. Leave the cartridge slightly loose so it can move back and forth in the slotted openings.
   Now slip the overhang gauge onto the back of the head shell and use your eyes to sight down the tip of the gauge. Move the cartridge in the slots until the stylus tip is just in line with the end of the gauge. This is the proper location for the cartridge. carefully tighten only one of the screws and re check to see that the overhang is still correct. Now, remove the gauge , and looking a the outline of the cartridge body against the headshell outline, slightly rotate the cartridge body until it is square with the head shell outline. Now tighten the remaining screw and recheck. If all is correct, replace the stylus guard and this step is now complete. If your turntable does not have an overhang guage, you will have to seek out an aftermarket alignment gauge or protractor.

P-Mount Style
  P-Mount or T4P style tonearms are very easy to install cartridges into. The tonearm terminates in a square socket and will usually have a single screw on the right hand side. Remove the screw. Take the P-Mount cartridge and insert it into the mating tonearm socket. Be sure it is inserted all the way (The screw will not go in unless the cartridge is fully seated.) Insert the screw and tighten snug. Since P-mount cartridges and tonearms are designed to install with perfect alignment, there is no alignment procedure. This step is now complete.

Cartridge Wiring
   If you have some DeoxIT or ProGold contact enhancer. apply it now to the cartridge pins.
   If you are using the Technics original head shell, you must open the connections slightly to make attachment easier or risk breaking them. If you look closely at the connectors at the end of each wire, you will see that they have a slot that runs the full length. Grasp the connector at its rear(where the wire is crimped) with the needle nose pliers, and push the screw driver blade into the opening just a little to widen the slot. Do this to all 4 wire connectors.
Now, select a wire, Grasp the connector at its rear(where the wire is crimped) with the needle nose pliers, and push it on to the cartridge's matching color connector. If there seems to be too much resistance, go through the spreading operation described above and open the connector up a little more. Attach the 4 wires and this step is complete.

Tonearm Setup & Adjustment
   First, insert the headshell into the tonearm. Most tonearms use a bayonet pin style collar locking mechanism. The pin is on the headshell. insert the headshell, pin facing up, into the end of the tonearm. Holding the headshell in position with one hand, rotate the knurled collar nut on the back of the tone arm, and you should see the head shell being drawn into the tonearm. Tighten snug. (Note: never remove the rubber washer on the end of the headshell. it is important.).
Locate the counterweight. Slip it onto the back of the tonearm and push it all the way forward. You should be able to read the counterweight dial scale from the front of the turntable
Now, remove the stylus guard, and unlock the the tonearm from its rest.
Holding the tonearm lightly against the rest with one hand, begin rotating the counter weight clockwise. The weight will be moving towards the rear. Keep checking the condition of the tonearm at the arm rest. You will reach a point where the tonearm just begins to lift off of the arm rest. STOP turning the counterweight, This is the Zero position..
Now, lock the arm back down. Hold the chrome part of the counter weight with one hand and turn the dial scale to read zero. Friction coupling will keep the dial set properly.
Now, turn only the chrome part of the weight counterclockwise until the scale reads the desired tracking force.

   Set the anti-skate setting to the same number as the tracking force.

The Tonearm Height
   If your turntable has a tonearm height adjustment, set it this way.
Place an old record on the turntable and cue the needle down in the center, It need not be turning.
Now come down so that your eye is level with the platter. Sight the tonearm from the left or right side of the turntable. Does the tonearm wand appear parallel to the record? It must be to perform it's best. Make a note of the condition (too high, too low.) and adjust the tonearm height as required to achieve this condition.

Finding The Best Location
   Few turntables made today have springy suspensions. Therefore today's tables are more sensitive to foot falls. The best location for a turnable is a wall mounted stand. This will eliminate problems from floor bound vibrations. Home centers have good wall shelf systems that work very well and are adjustable

Connecting The Turntable
   The turntable will have a left signal wire, a right signal wire and a electrical ground wire. Connect these to your stereo or phono preamp. Connect the ground wire to the screw provided or, if no screw was provided, then loosen a chassi screw and use that. The ground wire is important in minimizing hum.
I'm Hearing Alot Of Hum!
   This is the most common problem encountered with phono playback systems. And it can be puzzling sometimes to track down. First, you must isolate the source. Is it :
  • The Stereo
  • The Phono Preamp
  • The Turntable Wiring
  • The Phono Cartridge

The Stereo
   Switch the stereo to CD or AUX, and with nothing playing, turn the volume up to your normal listening position. If there is no hum now, then we can eliminate the stereo. If there is a hum, powersupply service is probably indicated.

The Phono Preamp
   This will require one accessory, a shorting plug. You need to get a couple of standard RCA plugs from Radio Shack for instance, and you need to short the center pin to the outside ground. Now, in place of the turntable, plug the shorting plugs into the phono input. Now, set the stereo to phono and turn the volume up to your normal listening position. If there is no hum now, then we can eliminate the phono preamp or phono stage. If there is a hum, phono stage service is indicated.

The Turntable Wiring
   This will require one accessory. a pair of alligator clips. You can also get these at RS. You need to clip together, I.E. short out the left and right cartridge pins. Do this on the back of the cartridge. You needn't remove the cartridge connections. Just connect one pair of clips between the red and green pins and another between the white and blue pins. Now, set the stereo to phono and turn the volume up to your normal listening position. If the hum is gone now, then we can eliminate the turntable wiring. If there is a hum, something is amiss with the turntable wiring. either a bad connection. or perhaps someone has changed the factory wires for some "fancy" wires that do not give sufficient shielding.

The Phono Cartridge
   If you've come this far, then the problem must be the phono cartridge.
Most cartridges use hi permeability steel shells to protect the coils from electrical fields that can cause hum. However, not all companies use this system. As such , there are some cartridge brands that are sensitive to external electric fields and will hum. The only solution you have is to replace the offending cartridge. Or, if you love the sound and want to keep it, you will have to play with the location of the turntable and try to minimize hum. Sources of hum fields are power transformers in equipment, wiring in the walls, certain turntable drive motors. Experiment by listening to the hum while you move the tonearm through its arc(cued up!!) and see if you can find a null location that will give you the best results.

KAB Electro - Acoustics
P.O. Box 2922
Plainfield, NJ 07062
(908) 754-1479