EMI Shield: Theory, Circuit, Parts, Notes

This is Prototype IV-E

There is no product on the market that removes buzz. This will directly filter out the buzz. The technology has been around since 1932. I designed this circuit using only the theory and examples explained in the Radio Designer’s Handbook (4th Edition, 1952).

This has been a year-long project, but I decided it is time to publish the circuit. I call this circuit an EMI Shield. It kills the buzz caused by the power transformer getting to the pickup coils of the bass. This only works for a bass. I have not started a design for use with a guitar. That is a bit more difficult and will be a future project.

This is a game changer. I love this circuit. When the buzz is gone, the natural frequency of the bass strings stand out. The buzz mixes with the bass strings and makes it sound tinny or higher pitched than what it should. The bass sounds much nicer and it was hard to put down. So, after years of playing, I now have new blisters.

This project requires expert soldering joints and best to have an oscilloscope. I have designed the preamps to use the same components in order to keep the parts inventory limited to just a few sizes. It keeps the build much simpler.

Original Work, Copyright 2017 (circuit) Copyright 2018 (video) James D. Whiteside, II all rights reserved, For consideration only, no reproduction without prior permission.