Optonica SM-4100 Metal Chassis and PCB

This amplifier has a solid steel chassis and is a complete metal construction. The top and bottom plates, front and back plates, are metal. Even the control knobs are aluminium metal. This is probably why some of these units have managed to survive for so long. The total weight of this amplifier is 6.6 kg and its external dimensions are 430 mm × 75 mm × 382 mm.

The metal tarnishes over the years, and it is possible to use metal polishers to make it shiny again, however I prefer not to use anything strong. Instead, I cleaned it with some robot aftershave (WD40).

Manufactured to very high-specifications, this PCB has a Tin HAL.

There is a separate PCB for the volume and balance controls.

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