The 7100 has only the transformer common to the various channels. (Well actually 3 channels use one xformer, the other 4 use the other) Because of this, there would be little interchannel dependance including power avail. I imagine there would be a very slight power reduction with all channels driven due to flux change in the xformer. Each channel has its own filter caps, so no dependance there. I suppose the house AC line voltage drop to the unit could cause a slight reduction in power too