Alphason HR-100S Arm

Hi, It's an allen wrench inserted in the small hole on the platter side of the platform. The hole is offset to the rear and the wrench goes in at an angle. Don't know the exact size. They go from small, extra small, tiny, miniscule, and microscopic.  Tiny might get it.

I don't have a sizing block for these or I'd tell you. I pick them out by sight. If you want the exact size contact Audio Origami:

http://www.audioorigami.co.uk/tone-arm-rewires/

If you have the arm in front of you, you'll see the hole is not perpendicular to the cue lever cylinder along the mounting platform.  Because it's set back, it's a PIA to adjust. With the arm mounted on a table,.it might be impossible.  

Also, the headshell lifter is ridiculous, but this is easily replaced with a ProJect (or any) replacement part. You might have to snip off half the piece due to the central headshell protrusion.  Other than those minor faults, the arm has a lot going for it, most notably the one piece titanium construction. Eff mass is in the 11g range, but it performs more like a low mass arm with med/high cu cartridges, that is in terms of resultant transient response.. High mass arms tend to sound sluggish with those carts, IMO.

That should read -

If you have the arm in front of you, you'll see the hole is not perpendicular to the cue lever cylinder relative to the side of the mounting platform. 

Braad8, not that big of a deal, just did this yesterday on a big SOTA and it is totally enclosed in a cabinet w a top.  Contrary to Fleib, adjusted cue height with arm on table in the cabinet!!!  Be brave.  Most definitely .035" for the cue height. 

http://www.ebay.com/itm/035in-BriteGuard-Plated-Hex-L-wrench-Long-1pc-Bulk-/182418740741?hash=item2a79011605:g:~GoAAOSwUKxYdtNZ

Agreed with Fleib it is a PITA. Very correct, the access hole is not perpendicular  However, this can be done.  Fish around with the .035.  it is a very small hex wrench.  Try to change the angle of approach with the wench until you feel the wrench lock into the bolt head.  Put the long arm into the port.  Twist the short arm.  I have never overtightened for fear of stripping.  You are dealing with vintage metal and plastic here, don't get too ham fisted. 

When you do get it set up correctly it may seem a little weird at first, with the cue in the full up position it appears that the entire cartridge will not clear the LP until you move the arm towards the platten and it hits the raising bump thus clearing the LP.

If it is stripped you could have arrived at destination F****D!  Machine Shop may have an idea?  Drill it out?  Could screw it up more trying to MgGyver.  John at Audio Origami should be able to figure it out or at least give you some ideas.  Check his website forum.