In my experience some isolation trannies are more suitable for audio application than others. You can hear tonal differences as well between those trannies. I think it has to do with the characteristics of the (iron) core of the isolation trannie in conjunction with the unit's power supply that has been attached to the isolation trannie. For example: Tamura and Tango isolation trannies sound different (to my ears more musical, better) than some other trannies with comparable power that originally were not designed for audio. What do you think?
Chris
Chris