First, I'm loving my late 70's v4! My questions are impedance. On the back of the 810e, are 3 jacks. Top jack is for top 4 10s. then there are two jacks under it. I've been plugging into the lower right, engaging all 8 10's. The question regards the labeling of the jacks, they all seem to be 4 ohms. What is the second lower jack for? What are the referring to when talking about stereo? The V4 is set a 4 ohms, the jack is labeled 4 ohms for the 8 10's. Is this right? I can run the top 4 at 4 ohms, and then all 8 at 4 ohms? It sounds good, just want it to be correct. Also, the foot switch on the V4, is it for the reverb or a channel switch, possibly a pre amp pot switch? I love this pairing, I'm getting great tones, fuzz, and plenty of volume, I just want to have a better understanding of the possibilities available with this head.