Desktop Audio Amplifier Chassis

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Project Summary

This was a quick build of a 50W desktop audio amplifier based around the SainSmart 12V 50Wx2+100W TPA3116D2 board. The amplifier performed well into a 6 Ohm load and was able to hit “uncomfortable” levels (at a 4 foot listening distance) without distortion.

Parts List

  • SainSmart 12V 50W x 2+100W TPA3116D2 2.1 Amplifier Board
  • Self-Stick 1/2″ Noise-Dampening Bumpers
  • Kmise Z2807H3 14 x 17 mm Mini Aluminum Knob
  • Black and Red Plastic Shell Speaker Terminal Binding Posts
  • BOX3-1455N-BK Black Aluminum Box (6.30 x 4.06 x 2.10 in)
  • 2.1mm Metal Panel Mount DC Power Jack
  • 3.5mm Stereo Panel Mount Input Jack

The Build

This project did not require any significant electrical design and was more an exercise of fitting components inside a relatively small enclosure. The initial plan was to have both RCA and 3.5mm inputs but the final product contained only the 3.5mm input due to the very limited space inside the enclosure.

amplifier components

SainSmart Amplifier Board

The build quality of the amplifier board was disappointing and was the cause of significant frustration during the build of this project. The biggest issue was the fact that the potentiometers were not evenly spaced and were also crooked.

Secondly, the power switch was slightly recessed which meant that the mounting holes for the potentiometers had to be drilled out to a larger diameter in order to allow for the switch to come out for enough to be reachable. The obvious solution would have been to desolder all the pots and resolder them properly. I did not do that.

Drilled Faceplate
Faceplate with uneven holes drilled out.


About the hardest part of this build was fitting the amplifier module in the chassis and cutting out the holes in the faceplate at the correct height. Due to the poor assembly of the board, no assumptions could be made about any features being equidistant so there was a lot of measuring and even more informed guessing.

Mounted Board
Board mounted into chassis.
Outputs connected
Audio outputs connected to speaker posts.
Rear View
Rear View
Front view
Front view.

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