Mre2007,
IIRC, the hex key for that adjustment is metric and VERY small. You'll need a set of keys with several sizes < 1.0 mm.
If you want fine arm height adjustment without raising the arm too much, consider something like the Expressimo collar. It's so thin it doesn't add even a mm in height at the lowest position. Much better than the stock OL collar.
It's a pain to adjust arm height on a Rega, but precise VTA/SRA will matter more with a ZYX than with a 103D.
IIRC, the hex key for that adjustment is metric and VERY small. You'll need a set of keys with several sizes < 1.0 mm.
If you want fine arm height adjustment without raising the arm too much, consider something like the Expressimo collar. It's so thin it doesn't add even a mm in height at the lowest position. Much better than the stock OL collar.
It's a pain to adjust arm height on a Rega, but precise VTA/SRA will matter more with a ZYX than with a 103D.