Calibrating ZMPT101B Voltage sensor issues

CLASS-D Single output. A few of the amps we deal with use a bridged-mono type output and have signal on + and - speaker terminals instead of a ground reference on the negative terminal, but those are somewhat rare.

And 62VAC is actually what I would consider medium power for what we deal with. We deal with amplifiers that produce over 100V AC clean output. We deal with 10-12K Watt amplifiers somewhat regularly. I would like to make this also be able to measure amplifiers that large as well.

Any links or diagrams on how to build this circuit you could help me with?