Alignment of early models of the SME 3009 tonearm

Posted by bkearns on January 6, 2004 at 11:37:34

In Reply to: SME 3009 Ser. 2 Imp. protractor question... posted by Ivan303 on January 6, 2004 at 08:03:52:

Alignment of early models of the SME 3009 tonearm

Hello,

The earlier 3009 series tonearms: - 3009 series I, 3009 series II, and 3009 improved / S2 improved which have a serial number that is less than 439606, have an arm tube that is designed for cartridge alignment according to the method laid down by Stevenson. In other words, the designers intended for the cartridge to be set in the headshell so that null radii occur at 60.325mm and 117.42mm. For these early tonearms, the linear offset will be 88.87mm when a cartridge is squared up in the headshell.

A single point protractor was provided for alignment of these tonearms; the centre of the grid on this protractor was located at a distance of 60.325mm from the turntable spindle. As discussed here before, it is possible to ensure alignment of a cartridge at two chosen null-radii by simultaneously ensuring that the cartridge is squared up in the headshell, and by adjusting the overhang so that the cartridge is aligned on one grid on a protractor.

Later models of the 3009 tonearm were re-designed for an alternative alignment system. When one these tonearms is aligned according to the instructions, the null-radii fall at 66.0 and 120.9 â€“ ie the alignment is consistent with the method which minimizes peak tracking distortion. For these tonearms, a two point protractor was provided, however the alignment procedure did not change; the extra grid on the protractor was only introduced to enable double checking of correct alignment.

For alignment of an earlier 3009 tonearm, using a conventional protractor with null radii at 66.00mm and 120.9mm - such as that produced by SME for later tonearms - the cartridge should be skewed inwards by just over 1 degrees in the headshell. This will produce the correct linear offset â€“ ie 93.45mm.

Best regards,

Brian

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Follow Ups Full Thread

Topic - SME 3009 Ser. 2 Imp. protractor question... - Ivan303 08:03:52 01/6/04 (4)

Re: SME 3009 Ser. 2 Imp. protractor question... - Tetrack 14:43:09 01/6/04 (0)

Alignment of early models of the SME 3009 tonearm - bkearns 01/6/0411:37:34 01/6/04 (2)

And for the 3012? - Brian C. 23:49:23 01/6/04 (0)

Sounds pretty complicated... - Ivan303 12:04:24 01/6/04 (0)

Follow Ups

Alignment of early models of the SME 3009 tonearm - bkearns 01/6/0411:37:34 01/6/04 (2)

And for the 3012? - Brian C. 23:49:23 01/6/04 (0)

Sounds pretty complicated... - Ivan303 12:04:24 01/6/04 (0)

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