Pioneer PL-570 Turntable auto-return voltage setting jig

thingiverse

The Pioneer PL-570 (wood base, not the plastic s*** from the 1980s) has an auto-return feature that stops working after a few years. Assuming you have a functioning tonearm motor that does not have a broken gear, this jig can be used to set the correct detector voltage for the auto-return. (See my gear sleeve for a cheap fix to a broken gear) On the detector board, you will find the potentiometer, v101, that should be at 2.5v. If it is reading 11-14v it is in dire need of cleaning and thus must be turned. You may also have turned the tonearm auto-return adjustment screw (the one that says DO NOT TOUCH in the manual that you probably don't have). Once either the pot or the screw has been moved, you have to recalibrate the slit/LED sensor based micro-switch voltage that controls the auto-return. In the downloadable service manuals, you will find the procedure for adjusting this voltage. It requires this jig. The arc in the base of the jig is 60mm from the center of the spindle hole as described in the manual. You could use small screws to hold the riser (pt2) in place, but I never tested this part of the design. I simply used painters tape to hold it all in place. The riser is necessary since head-shells are variable width. My auto-return was adjusted to the 2.5 +- .5v easily with this jig. (The procedure works well for the pwx-017 detector board that showed up in later models)