4 TOTALLY DIFFERENT – Surface Mount Amplifier Protoboards 4 - TOTALLY DIFFERENT - PROTO-CHIP Surface Mount Device/Amplifier Prototyping Boards! Size is 1.8" X 1.8 " FR-4 material, no crappy thin copper! 0.65 mm on second board. Repairing or modifying anything, with a small circuit board?. byJuly 5, 2026