I have a roksan tabriz arm on a diy TT. I have a good range of adjustment on the pivot-spindle distance.
I took the arm off today to do a job (it had been ages since I had it off) and when putting it back, I looked up the specs for the arm. a spindle pivot distance of 222mm is recommended with an effective length of 240mm. So using my feickert alignment tool, I set it up. However, there's an issue...... I can't align the cart (benz L2) on any of the 3 normal adjustments (baerwald, lofgren or stevenson) as the cart backs right up against the screw holes.
If I bring the spindle-pivot back out to 224 or 225mm, I can align easily enough.
I should add that I obviously had this issue before and sorted it, but that was before I had the feickert protractor and I most likely aligned it using a paper template.
Anyone come across this?
Fran
I took the arm off today to do a job (it had been ages since I had it off) and when putting it back, I looked up the specs for the arm. a spindle pivot distance of 222mm is recommended with an effective length of 240mm. So using my feickert alignment tool, I set it up. However, there's an issue...... I can't align the cart (benz L2) on any of the 3 normal adjustments (baerwald, lofgren or stevenson) as the cart backs right up against the screw holes.
If I bring the spindle-pivot back out to 224 or 225mm, I can align easily enough.
I should add that I obviously had this issue before and sorted it, but that was before I had the feickert protractor and I most likely aligned it using a paper template.
Anyone come across this?
Fran
Download John Elison's Alignment Spreadsheet and use it to determine what's possible and what isn't. You may decide that the arm manufacturer's mounting distance recommendation isn't what you want. It wouldn't be the first time an arm manufacturer has suggested sub-optimal numbers. You might also want to download my arc template generator (3rd item down) and see if it agrees with the Feickert.
Thanks for the links.... I'll be checking those out. I have a test record and there's a fairly good template with that, albeit paper. I'm going to do some comparisons with that next and see.
I know that roksan use null points different to baerwald/lofgren/stevenson, but surely you should still be able to align one of those with their arm.....
Its so much easier with linear trackers!
Fran
I know that roksan use null points different to baerwald/lofgren/stevenson, but surely you should still be able to align one of those with their arm.....
Its so much easier with linear trackers!
Fran
As I understand it, the pivot-to-spindle distance is just a guide which should enable you to get the stylus in the right place, according to whichever alignment method you choose (Baerwald, Loefgren or Stephenson).
So if you have the ability to adjust the arm mounting distance ... do this until your stylus is in the correct place (ie. forget about the mfr's pivot-to-spindle recommendation). IE. the stylus-to-pivot distance is the important thing.
If you have an arc projector like Conrad's, when the stylus is set at the right distance from the pivot, it follows the arc.
Regards,
Andy
Thanks guys...
what's interesting here, is that if I use the paper template that comes with the hifi news record (full size round paper disk) and align the cartridge, then go back and put on the feickert gauge, the alignment is very visibly off. Surely the 2 should agree?
I think thats whats really bugging me. The feickert gauge (at €200) should be far more accurate than a paper disc, but yet I get far more mistracking with it than with the paper disc.
Obviously I'm missing something here.....
Fran
what's interesting here, is that if I use the paper template that comes with the hifi news record (full size round paper disk) and align the cartridge, then go back and put on the feickert gauge, the alignment is very visibly off. Surely the 2 should agree?
I think thats whats really bugging me. The feickert gauge (at €200) should be far more accurate than a paper disc, but yet I get far more mistracking with it than with the paper disc.
Obviously I'm missing something here.....
Fran
I have the HFNRR Test LP but I do not use the protractor that came with it.
Apart from the Feickart (as I haven't used one), IMO the only protractors to get are arc-based ones. Like the Wallytractor and the Accutrak. But you can use Conrad Hoffman's cool program to print off one suitable for your arm (only problem which I have found with his program is that's it's frustrating to get the print to scale correctly!! 😡 )
Regards,
Andy
See, as I understand it with the feickert:
Set the bar at the top so that it points right at the pivot point. Lock the table so that it stays right there. Then use the middle set of points for lofgren, baerwald etc to set the overhang correctly. Then go back to either set of outer points and line up the cart.
If you have the pivot point selected correctly, then the overhang should be perfect (since you have the points of the triangle all locked down).
The tabriz arm has a big flat over the pivot, so I machined a "cap" that slips on to the top of the arm pivot housing with a dimple in the top just to make 100% sure I had it right.
Fran
Set the bar at the top so that it points right at the pivot point. Lock the table so that it stays right there. Then use the middle set of points for lofgren, baerwald etc to set the overhang correctly. Then go back to either set of outer points and line up the cart.
If you have the pivot point selected correctly, then the overhang should be perfect (since you have the points of the triangle all locked down).
The tabriz arm has a big flat over the pivot, so I machined a "cap" that slips on to the top of the arm pivot housing with a dimple in the top just to make 100% sure I had it right.
Fran
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