Source components: VPI HW19 turntable, Rotel 955X Cd player, Wright WPL-20 Preamp, Transcendent 150 watt monoblocks. When I was talking to Jim during the purchasing/construction phase, he said there wasn't much mechanical break in that he was aware of but some people had noticed a change in sound after a longer time period had elapsed than expected. I don't really know if that was it or the tube change or maybe the planets are aligned correctly now but things sound better than ever. I took delivery of these beauties December 23rd. BTW.