Bernard, after reading your post I made one of my rare visits to the Outlaw "Saloon" to read that thread. The discussion there is a bit tangled-up and doesn't cover the FTC requirements clearly. The link you gave here is certainly worth reading for those who may react with interest(or horror)in seeing an example of how government regulations are made, but the full text of
the amplifier reg isn't included. Another FTC discussion more directly bearing on the question of how many channels driven is found
here. Note that the interpretation of "all associated channels" as meaning two, which was the case when the reg was first promulgated in 1974 is still in effect. There has been no further action on the question for about four years now, although the Commission has left it open.
So, as we discussed before, the requirement is two channels driven, along with the other described requirements. Of course manufacturers can, and some do, choose to state an all channels driven spec if it's arrived at in compliance with the written requirements for the test.
