Thank you audioguru for the info and please don't think I question your answer because I know next to nothing about electronics. Here's the rub, I just put a small voltage bench supply together, two 14v outlets, one plus, one neg, using center tapped trans. I was curious as to whether this one could be modified so as to have more output v and amps than the first one and have +/-. I have the parts for this 30v supply on order and thought maybe with some changes I could do what I asked about. Probably to late for that now?