DIY LM1875T 2.0 Amplifier Build Guide

If you’re interested in building your own LM1875T 2.0 amplifier, this article is worth checking out. Since this DIY project doesn't include a high-performance heat sink, it's best not to drive large speakers for now.

The amplifier consists of three modules: the power supply module, the op-amp module (you can use a dual NE5532), and the amplifier module (LM1875T).

1. Power Supply Module:

You'll need a dual 15V toroidal transformer with dual input and four output lines. Two outputs go directly to power the amplifier module; the other two go through the 7815 and 7915 LDO voltage regulator chips to power the op-amp module. Since the op-amp module isn't ready yet, the wiring remains disconnected for now.

The PCB for the dual-voltage rectification, filtering, and regulation module is shown below.

Circuit diagram shown below.

2. Amplifier Module:

You'll need two LM1875T amplifier chips — one for the left channel and one for the right channel output.

PCB and circuit diagram are shown below.

The physical layout of the power supply module is shown below. If you don't have components like fuses yet, you can temporarily replace them with copper wire.

The physical layout of the amplifier module is shown below. In the design, to make PCB routing easier, the power ground and signal ground are not separated. Left and right channel power and input connections require jumpers, which may make wiring more complex later — so you can optimize this part further if you like.

The overall setup is shown below.

The End