Homemade Chassis for LM3886 Power Amplifier

The project is designed around dimensions where a LM3886 chip amplifier kit is tightly packed in a simple chassis the uses four aluminum panels and two heatsinks.

The LM3886 is a high performance audio power amplifier that is capable of delivering 68W of continuous average power to 4 Ohms load and 38W into 8 Ohms load with 0.1% THD from 20Hz-20kHz. The performance of the LM3886 is in a class above discrete and hybrid amplifiers since it utilizes Self Peak Instantaneous Temperature (°Ke) (SPiKe) protection circuitry. The parts are completely safeguarded at the output against overvoltage, undervoltage, overloads, shorts to supplies, thermal runaway, and instantaneous temperature peaks.

In this project design, the top and bottom panels sit in ridges cut into the heatsinks with a table saw and then bolted into the end fins are the front and back panels. M3 nuts and bolts hold the rear panel fixings while M4 bolts tapped directly into the heatsinks hold the panels that join to the heatsinks without requiring additional brackets.

The heatsinks have a dimension of 160 × 75 × 50mm with a 10mm thick base with 3mm top/botoom and 8mm front/back panels.