Vox Valvetronix ToneLab LE Owner's Manual page 19

0 Shuttle driver needle contact adjustment
Adjust so that the needle groove of the shuttle hook
thread guide O is at the center of the needle, slide the
thread guide lightly in, and then retighten the screws.
0 Shuttle hook thread guide adjustment
0 Two-step work clamp adjustment (independent presser foot solenoid type)
stopped.
(1) Lower the presser plate O. Loosen screw O and nut 0 to adjust the gap between the work clamp O and feed
plate 0 to 0 mm, and then tighten screw 0. Spring 0 will be minimally tensioned at this time.
Now tighten screw O and nut 0.
(2) Lift presser plate 0 again, and loosen nut 0. Adjust guide stud 0 so that the height from the needle plate top
to the work clamp O is 18 mm.