How critical is alignment error??

Rodman,

Yes but he can plug in the deviation and check the change in distortion. He can even print a new protractor to compensate. A lot can be done. Remember effective length is a design element with a nominal figure. Take a look at an SME where there is no nominal length but an exact length but yet pivot to spindle distance can be changed and that is all. The headshell if fixed for all parameters for the most part. If you are lucky a poor setting can end up being the correct setting. Just like some arms can be setup w. Lofgren A or B.

Like I said, "without the ability to correct the figures for the error." Where is that option provided, on the Vinyl Engine website(the only one you mentioned)? Maybe I missed it.

You can approximate unknown or non-standard parameters by using a separate alignment calculator to come up with the unknown parameters.

For example, if we assume that the design geometry of the original tonearm was for Lofgren A/Baerwald then the parameters are as follows...
Effective length: 232.8mm
Overhang: 17.8mm
Pivot-to-spindle: 215.0mm
Offset angle: 23.7 degrees

And the design geometry of the new tonearm is as follows...
Effective length: 239.3mm
Overhang: 17.3mm
Pivot-to-spindle: 222.0mm
Offset angle: 23.0 degrees

Then the current setup (based on Bifwynne's estimate of pivot-to-spindle distance) should have a geometry as follows...
Effective length: 234.7mm
Overhange: 17.7mm
Pivot-to-spindle: 217.0mm
Offset angle: 23.5 degrees

However, Bifwynne states that the overhang is about 3-5mm too long so, using the lower value, the overhang is now 20.7mm and effective length becomes 237.7mm. (What's missing is which alignment protractor geometry is being used to estimate incorrect overhang.) Compared to the "correct" alignment parameters the current setup doesn't look very promising, as shown in the chart and graph from VinylEngine

VinylEngine Tonearm Alignment Comparator

Regards,
Tom

Tom,

Well done. I am being lazy (actually playing w. my little one). But... depending on the headshell slots lengths maybe something can be done. I need to do some plug ins to the Comparator.

Dear Bifwynne: The other thing you can make is to change the effective tonearm length. Due that you know the precise/accurate S-P distance then your " new " set up patameters will be for overhang: 17.665 mm with an offset angle: 23.46°. This is using Löfgren A ( IEC ) but you can use the same Löfgren A with DIN standard and then the parameters will be for overhang: 16.68mm with an offset angle: 22.95°.

With both set up you could have a good set up. Use the one that permit your tonearm headshell slots.
If you can't make either set up then you have to re-drill that arm mount base to the right position.

Regards and enjoy the music,
Raul.