This is picking hairs and scare mongering, and just selecting a worst case scenario.The impedance of the amps is not the issue. The impedance of a 10K control is. Per your post prior to mine:
90% of amps are 33kohm input impedance or higher.
It doesn't matter one iota where the volume control is positioned here, these figures have a perfect impedance match regardless of volume position. As do 90% of sources and amps out there when mated to ***10kohm*** passive volume controls.*** emphasis added. With a 10K post, we can always count on the total load being less than 10K. At full volume it will be 7.5K, increasing to 10K at minimum volume in the example above.
Not to put too fine a point on it George, but your constant and false claims that active preamp manufacturers are only in it for the money is disingenuous at the very least; your remonstrations come off as hypocritical!
So how about you lay off? Others and I could have easily called you on it years ago; its become tiresome.