I posted at audio asylum, directly to Harry Weisfield of VPI,, the possible issues about initial voltage at the SDS, which I believed should be exactly 115V.
Harry concurred, and said yes, that start up voltages should be 115V, and if not, to give him a call ASAP.
When I fire up my HW-19, I first turn on the SDS. It will read 115V, then drop to the selected ramp down voltage, which in my instace is 72V.
Then, when I hit the power button on the side of my HW-19, to get the Platter spinning, my SDS will automatically ramp up to 115V for a short period of time, then automatically ramp back down to 72V,
A pretty slick device, I'm real happy with mine.
In conjucntion with my KAB Strobe Disc, and with the record in play, (The strobe disc is slightly smaller than a 33-1/3 LP, and permits accounting for Stylus drag) I get dead stable speed on my rig at 33-1/3 at exactly 60.17hz.
I get the exact same results when switching to 45rpm, (up to 115V, then down to 72V) but forget my personal "hz" settings offhand.
That the strobe doesn't waver-budge 1/32" from dead on for countless minutes. That's multitudes better than what I got minus the SDS in my system. Mark