Hello. I'm having trouble finding any info about what, exactly, the differences are between the mark i and mark ii versions of the SA-7500 amplifiers? I have gathered from this forum that most people thing the mark ii is inferior. What is different? I can see that the pre/power amp jumper option does not exist on the mark ii, as well as the reduced number of inputs. Does anyone know the differences in the guts of the two? Why did Pioneer move to the mark ii series? Was it a cost-saving measure? Finally, I have not been able to find an owner's manual for the SA-7500 ii (I have the service manual). Does anybody have one? Thanks in advance for any insight you can provide!