Rather than pollute the F6 thread, I thought I would start a new one to document the build. It has started rough. The idiot who did the boards, made multiple mistakes. I coorected them all and fires it up. I had oscillation. Realy didnt understand why, and then I spotted nother mistake. I had screwed up pinout of transformers as well. Original is inverting amp and mine was non inverting. Feedback was causing oscillation. Got iot switched and all is well. Here it is warming up. I will measure individual sides for distortion and then connect and measure balanced version. Don't expect speed from me.