I built these today. Despite appearances, no welding was required. That's all 1/8 inch hardboard and 3/4 inch square hardwood molding, hot glued together. Then I sealed, painted flat black, applied iron-powder paint in various locations, then applied rust agent in multiple layers to get a nice effect. Then I pulled some parts off the TechShop Wall O' Junk and glued them on for extra zing. The tubes contain 10 ShiftBrite modules each, and will be used as left and right VU channels.