2. analog
  3. 1385992225

Set Overhang on arm w/adjustable tracking angle

I am setting up a Clearaudio Satisfy 9" straight tonearm that is infinitely adjustable for tracking angle. I have set up the 222mm pivot-to-spindle distance. Now I need to set the overhang to 14mm. Since I have to twist the cartridge to set the tracking angle (which is unknown), how do I set the overhang? Both the overhang and the Lofgren alignment require twisting the cartridge. In other words, I don't think I can set the overhang unless the Lofgren alignment is achieved, but I can't set the Lofgren alignment until the overhang is measured. In addition, I have to measure the overhang after the cartridge is twisted. Is this a case where I just have to adjust both alignment and overhang until I measure 14mm overhang and the correct Lofgren alignment?
garibaldi

Showing 2 responses by john_gordon

john_gordon
116 posts
 

Garibaldi,
Doug has has given an excellent summary. The only point I would make is that your arm should have 17.31mm overhang not 14mm.

Peter,
It is interesting that few of the current arms with the facility to rotate and slide the cartridge choose to do as you suggest. It seems an obvious design advantage, particularly if the two movements are kept separate. It is, of course, simpler and cheaper to combine the two functions on a bar between the cartridge mounting holes.

John

.
john_gordon
116 posts
 

Doug,
I know there was a large variation in that cartridge dimension in the "good old days" but I was under the impression this had more or less standardised on 9.5mm. So aligning the pivot to that dimension on the assumption it will be within a mm or two must introduce less error by almost a factor of 10 when rotating the cartridge than if the pivot is 9.5mm away.

A facility for an adjustable pivot to stylus distance together with a cartridge mount that only rotates is another way to do it to avoid the two settings interacting. But then an arc protractor couldn't be used. It would have to be one based on the Dennesen principle or a standard two point.
John

.
More to discover