MintLP arc protractor

Do you know if Yip will be basing the protractor on Stevenson or Baerwald or Loefgren? I am curious because I heard that Stevenson is best if using a mounting distance of 222 mm. Not sure how credible this is.

Since a Rega is not designed for Baerwald, *some* cartridges may be too short (from the plane of the mounting holes to the stylus) to be aligned using that scheme. The headshell slots may not allow shorter cartridges to be slid far enough forward to achieve alignment.

Not a common problem, but not completely unknown.

Yip is a great guy and makes an outstanding product, but he can be a bit, how should I put it... "over the top" with regards to insuring that your spindle to pivot distance and effective length is exact.

It took well over a month of back and forth emails and even sending numerous photographs of my setup to convince him that my Jelco arm did, indeed, have an achievable effective length of around 235mm.

The MintLP protractor is painstakingly precise and I understand Yips need to get these measurements as close as possible. However, a millimeter or two +/- on spindle to pivot distance can usually be accommodated for via the headshell slots.

All that being said - trust me that it'll be worth it in the end. It's the most precise protractor I've ever used.

If you're concerned about your headshell slots having enough 'play' to allow you to mount a specific cartridge, I'd suggest you first print out an arc protractor on conrad hoffman's site http://www.conradhoffman.com/chsw.htm, using your measured Spindle to Pivot, as a test before you order Mint's device. Also, maybe doing that will help convince Mint that the StP that you've given him will actually work.

Greetings,

The problem here is that the turntable in question has already had its tonearm mounted, and save some potential play in the mounting hole, its pivot-spindle distance is fixed.

Normally, you establish a pivot-spindle distance from the effective length before mounting the tonearm, but using (for example) the Ellison spreadsheet, you can work this backwards.

So, assuming it's an accurate Rega Stevenson mount, you have a 222mm pivot to spindle distance which resolves to ~ 237mm eff. len. for Stevenson and ~239.3mm for Baerwaald.

This 2.3mm (approx.) difference is what Doug was referring to when he said you might run into problems with a "short" cantilever - meaning a cartridge whose stylus is positioned considerably closer to the mounting bolts than the 9.0mm statistical norm.

There's a potential for your not being able to slide the cartridge forward enough in the headshell slots to achieve the 239.3mm effective length. This is why Yip is being so persnickety.

As Johnbrown wisely suggests, you can do a proof of concept by printing out a Hoffman protractor. This will set your mind at ease.

Cheers,
Thom @ Galibier