I Fixed My 40 Year Old Test Box! New Prototyping Rig!

My nearly 40-year-old breadboard test rig finally gave up mid-project — right as I was preparing to build a 4 Quadrant Multiplier / Ring Modulator. Rather than repair it yet again, I decided it was time to design and build a new custom test harness with the features I actually use.

In this video, I walk through the entire process of rebuilding my electronics test rig from scratch, focusing on simplicity, reliability, and practical bench features for audio and guitar effect development.

In this build, I cover:
Diagnosing problems with the original test rig
Pointing out previous repairs and design limitations
Deciding which features matter (and which don’t)
Planning a new layout for the breadboard rig
Adding practical upgrades like:
Extra input jacks
Bi-polar power
Additional ground posts
Building the new test rig step-by-step
Performing quick buzz-tests along the way to verify connections

With the new test rig complete, I’m finally ready to get back to the Ring Modulator / 4 Quadrant Multiplier project that’s been waiting on the bench.

If you build or modify your own test rigs, I’d love to hear what features you consider essential.

Links to my channel...
Follow along for upcoming projects, experiments, and circuit explorations:    / @madscientistguitarlab  

If you like the ideas and experiments happening here on the channel, you can go deeper with my books on The History of the Cigar Box Guitar and Cigar Box Guitar Amplifiers.
Affiliate links:
One Man's Trash 2nd Edition A History of the Cigar Box Guitar: https://amzn.to/4hgTpgK
The Cigar Box Guitar Amplifier Notebook: https://amzn.to/43nBgrX
Breadboard and Test Leads: https://amzn.to/44KzdPu