Numark TTUSB tonearm adjustment Options

[rocket_pc]

I have first browsed the wiki for this, though only a few minutes. My question is about adjusting the tone arm on the Numark TTUSB. Can anybody tell me where there are instructions on adjusting the counterweight on the tone arm of the Numark TTUSB and adjusting the anti-skate mechanism?

I got the turntable yesterday. The instructions in the operator's manual is insufficient, with only a few sentences on the subject that seem very ambiguous to me.

The manual says,

...there should be a feeling of weight and resistance when the head shell is raised and lowered. Begin rotating the counterweight clockwise (away from the pivot point) until the weight and resistance feeling is gone. If done properly, the tone arm will pivot with very little resistance back and forth indicating that there is exactly 0 grams of stylus pressure. With the counterweight in its new position further away from tone arm pivot point, grasp the scale ring of the counter weight and rotate it until "0" is in the vertical position. Finally, rotate the counterweight (and scale ring) counter-clockwise (towards the pivot point) until the desired amount of weight is reached. If the scale rotates 360 degrees beyond the zero point, the new scale ring reading should be added to 3.5.

I don't understand these instructions at all. I remember seeing somewhere last month, when shopping for this, mention of some website or other with instructions on adjusting the tonearm and antiskate functions.

Thank you, in advance, for your attention on this subject.

Don

This post has been edited by greynol: Dec 11 2009, 22:04

Reason for edit: Please use the default font. Placed quote in the proper container.

[pdq]

As the record turns, the needle dragging in the groove produces a force due to frictiion. Because the tone arm is at an angle with respect to the groove, part of this force is exerted as a sideways force, or skating force. This force tries to draw the needle toward the center of the record. If there were no anti-skating correction then this would cause the needle to press harder against one side of the groove than the other.

Since the frictional force is proportional to the tracking force (the downward force of the needle against the record) the skating force is also proportional to this, which is why the skating force needs to be adjusted with the tracking force.

[cliveb]

As the record turns, the needle dragging in the groove produces a force due to frictiion. Because the tone arm is at an angle with respect to the groove, part of this force is exerted as a sideways force, or skating force. This force tries to draw the needle toward the center of the record. If there were no anti-skating correction then this would cause the needle to press harder against one side of the groove than the other.

Actually the stylus should not be at an angle with respect to the groove. (Of course on a pivoted tonearm, most of the time it is *slightly* out of alignment). The source of the sideways force is due to the overhang. A pickup arm with zero overhang doesn't generate any sideways force.

So, you may ask, why have an overhang? Because it improves the geometric alignment of stylus to groove over a wider portion of the LP side. This benefit outweighs the downside of needing to add antiskate. (Ever noticed that linear tracking tonearms have no overhang?)

The best way to set antiskating is to start at or slightly above the tracking force, then adjust by ear. As Axon says, it's very difficult to get it right for every LP, so don't stress too much about this.