by Graeme Dennes » 07 Dec 2008 04:23
It's been a long time coming to the fore. Erik Löfgren was indeed the first to provide the optimum alignment geometry solutions (in 1938) to minimise the distortion resulting from lateral tracking error with a pivoted tone arm, by minimising and equalising the weighted tracking error at the three peaks across the record playing surface.
I hope we can now continue to recognise Löfgren's pioneering research findings by referring to his name in relation to the subject of optimum tonearm alignment, given that the later researchers (starting with Baerwald in 1941) "discovered" alignment geometry solutions identical to Löfgren's on each occasion, as my 1983 (and later revised) analysis shows. This solution is known as the "Löfgren A" solution.
He also developed the alternative "Löfgren B" solution, which reduces the distortion between the null radii by reducing the weighted tracking error in that region, as a trade-off against higher distortion at the inner grooves.
Both of these popular alignment strategies are due to Löfgren, and his name should rightly be associated with them.
Best regards,
Graeme Dennes