Leach Amp

For the course Project audio at Vives Kortrijk i need to design an Leach Amplifier, we were told to base our design on this design https://leachlegacy.ece.gatech.edu/lowtim/ by W. Marshall Leach, Jr. . The first step was to recreate the schematic in KiCad. This mainly involved carefully comparing my work with the original schematic (version 4.5): https://leachlegacy.ece.gatech.edu/lowtim/graphics/ckt.pdf Based on this reference, I produced the following schematic: Next, I selected the appropriate components. To keep costs as low as possible, I chose components sourced from China (LCSC). I used a mix of SMD and through-hole parts to achieve a compact form factor while maintaining the same performance and heat dissipation characteristics as the original design For the power stage, I decided to use large power transistors with thermal tracking. This is important because the diodes and transistors must remain at the same temperature to ensure proper bias stability. Using thermal tracking reduces the number of required wires and improves thermal coupling.

I also designed a custom stand to support both the PCB and the large heatsink.

The bill of materials (BOM) for soldering the PCB can be found here: https://tiebedeclercq.be/boms/LeachAmpV1Bom.html

There are still a few things left to complete:

• I need a large transformer to power the entire amplifier
• I want the amplifier to include built-in Bluetooth audio, a display with a control knob, and proper audio inputs.