I'd always presumed that as the Cheyenne PUII manual states it outputs 5-12v, that when it said the lowest speed (60) on the screen it was putting out 5v and when it said the highest (160) it was putting out 12v.

As I'm running a few other machines now I thought I'd double check it with a multimeter.

These are with a machine attached. The volts varied slightly depending on the machine so these are rough.
But still shows its a much smaller voltage range than expected.

160 = 12.09v
150 = 11.61v
140 = 11.14v
130 = 10.66v
120 = 10.19v
110 = 9.71v
100 = 9.23v
90 = 8.76v
80 = 8.28v
70 = 7.81v
60 = 7.33v