Why use a super accurate cartridge protractor

Hi Nandric,
you said

But there must be
the corresponding max. distortion at some other 'points'.
Well it seems to me that we should worry about those also.
I have never seen any numerical values for those in this forum. It may be the case that while I feel 'proud' about my own selection of the zero points my records are in a
sade state because of my choice?

For most alignments there are three maxima (Stevenson being a special case). Typical distortion values for these are (for a 230 arm) 0.65% for the three equal LogrenA/Baerwald IEC maxima and 0.42% average across the side.

For Lofgren B IEC the average is 0.38% but the maximum is now 1% at the innermost groove.

For DIN alignments, there is more distortion when playing a DIN LP but less at the inner grooves when playing a IEC LP. This is why I chose a DIN alignment 30 years ago.

Dertonarm's Uni-DIN alignment is a variation on this which reduces the inner maximum to 0.5% for DIN LPs and lowers the middle max to 0.5% while increasing the outer max to over 1%.

John
.

Hi Thekong

Dertonarm said

the alignment I did choose actually minimizes distortion in the last 2/3 ( not just last 1/3) of the record groove's radius

He should have said

...the alignment I did choose reduces distortion....

The alignment reduces it. It doesn't minimize it.

It can easily be reduced further, but at the expense of an increase elsewhere, which is the point being ignored.

Regarding changes in overhang and offset. For a 9" arm, if the overhang is increased by 0.5mm, and offset increased by 0.5 degree, they tend to compensate, as they also do when reduced by similar amounts.

If one is reduced as the other is increased, the errors add and the distortion increases. So you could have made unintended errors in your setup and they could sound ok. Or not.

As an illustration, if the overhang is increased by 0.5mm without the offset changing, you basically get Lofgren B, which may well sound better on your favourite album...

John
.

No offense intended, but the notion of "alignment by ear" is idiotic. This is simple geometry. Good alignment protractors trace a line that minimizes distortion across the surface of the record. Different alignments optimize different areas of the record.

Overall - do you want to minimize tracing error and tracking distortion on your analog setup? If so - then you want the most accurate protractor you can get. I use the MINT, and I can align my cartridge with a very high level of precision in 10 minutes with it

Apparently there is no need. Well Tempered tonearms do not allow for overhang adjustments, and the are well regarded by many.

Later

Goatwuss, I agree with proviso that 'idiotic' means something like 'mental aritmetic' versus ' calculator'.

Regards,