Only $5 for 10 PCBs and every new member get $5 bonus. + Express 24 hour / 48 hour service on https://www.pcbway.com/ ➠➠➠➠ In this project build video, I take you through the design and construction of a new Audio Load Switcher—a compact under-shelf fixture that lets me easily switch between my workshop speakers and a resistive dummy load (selectable between 4Ω and 8Ω). This is incredibly useful when working on radios, amps, or other audio gear at the bench.
Unlike my previous version (which used toggle switches that failed over time due to tarnished contacts at low signal levels), this new unit uses high-quality Panasonic relays to handle the switching—clean, reliable, and built to last.
As a bonus, the unit features BNC outputs for left and right channels, so I can monitor audio signals directly on an oscilloscope while testing.
If you’d like to build your own, I’ve shared the PCB layout on PCBWay’s Share Projects section—check the link below. I also share a Google Drive Folder with the Schematic, Gerbers, and 3D print files used to create the enclosure. It’s a great little tool that makes bench testing safer, cleaner, and more efficient.
🎥 XRAYTONYB video:
XRAYTONYB video link: https://youtu.be/fdwxDjbU23E?si=3zb68vI9l99I0weN
https://youtu.be/m06D2XC9nwQ
🔗 PCBWay Shared project:
https://www.pcbway.com/project/shareproject/Audio_Dummy_Load_Switcher_Using_Relays_9db476f7.html
🔗 Google Drive Shared Files:
https://drive.google.com/drive/folders/1r4G6wva9EG70eDXPSUPjIgMijg_kbfAu?usp=sharing
🙏 Want to support the channel? ●●●●●●
https://www.patreon.com/mcaldeira
https://paypal.me/macaldeira
This DIY audio load switcher project uses a Panasonic relay to switch between workshop speakers and selectable 4Ω or 8Ω dummy loads. It features BNC scope outputs for real-time signal monitoring, and eliminates common toggle switch failures. Designed as an under-shelf test fixture for audio equipment repairs, the build includes shared PCBs on PCBWay for fellow electronics enthusiasts.
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#AudioWorkbench
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