@KeithEmo Thank you for that in depth explanation! I think I'll have to do some more comparisons between my 4W iCan SE and the 50W A-100. The iCan SE has a 15V DC power supply, so I assume that's the max voltage it can provide. From what you explained, I'm assuming the voltage available should be the same regardless of gain setting, correct? Therefore with my planars, there should be no advantage using medium or high gain versus low gain as long as I can get adequate volume, right?