Threshold amp question

I have a Threshold Stasis II amplifier. In order to match it with a Vandersteen sub, I need to know the amplifier's input impedance. Does anyone have a Stasis II owner's manual or repair manual that could give me that information. I would be most appreciative. Thanks.
I have a Stasis 3 manual which also covers the 2. The answer for both is 75k ohms.
Thank you, Sparky57.