Signal tracer by ESP (Project 164)

The Signal Tracer project, developed by Rod Elliott, introduces a cost-effective method for diagnosing audio system faults. By tracing signals through circuits, it helps locate audio issues, especially in multi-stage setups. While not as precise as an oscilloscope, it narrows down faults, aiding troubleshooting for both beginners and experienced technicians.

The original project came from here:
https://sound-au.com/project164.htm

I only copied the schema and made a PCB for it, all the right to the original author :)

Note this project to work it needs a probe for oscilloscopes, a 8ohm/4ohm speaker, and a 9v power supply.