Originally Posted by
John Gordon
Hi Ronald
Have you checked the mounting distance? This is the only adjustable parameter you have, so if it isn't exactly set for the actual effective length which is governed by the SPU mount, then it could make a big difference. If you use a two point protractor, and adjust the mounting distance to optimise the error using nulls at 66 and 121. The offset angle is the unknown here, although I see it mentioned as 19 degrees in various places. However this may simply be because that is the figure that emerges for Lofgren A IEC when the effective length and overhang are used in the spreadsheets. If the angle is different then that may mean a different mounting distance.
The other thing is that you need to know if there is more or less distortion on one or other channel, as there may be an issue of excess anti-skate.
John