One of the bigger projects that John Camille cooked up before he passed away several years ago was a power conditioner for a whole system. It was massive, and somewhat complex - John would tend to gauge the effectiveness of a conditioner by the weight of the iron in it - enough so that I never built one. But I've had a power supply from an old computer mainframe for years that we can barely move with three people, that I figured to use one day as the basis. I'm more motivated these days, as the power in our business park has a cyclic voltage fluctuation that makes us crazy when trying to measure things in the lab. When I have some time I will dig up the notes he left me (John Tucker and I gathered up every scrap of his notes we could find when we helped to clear out his house for sale). If it looks like some of it could be worked up as a kit I'll give it some thought. If it looks too big and complex for that I might just share the notes.