This mod replaces the Caps with efficent ESA Clarity Custom Coupling Caps. Resistors  are replaced with Carbon Composition resistors by Xycon. The  diodes  are replaced with Hexfet High Grade Premium Diodes .This mod allows for more efficient transfer of Signal The result: an Improved sound stage with a tighter bass and crisper highs an overall better dynamic dimensional sound that is pleasing and yields performance found in units costing much more.This mod does not make the unit sound any less tube like.