Comment

Comment by Gary W aka Rev. Bluejeans on March 10, 2018 at 3:46pm

Turtle - very cool stuff!  I am a "magnet guy" and you're right about the steel plate - - a magnet on a steel plate has more 'reach'. Depending on the plate, it can make the magnet perform like it's twice as thick.

Comment by turtlehead on March 10, 2018 at 3:24pm

Here's another one:

I took a copper name plate blank, cut a hole in the middle and a slit cut in it to create a loop around the magnets. The magnets are stuffed in a piece of clear vinyl tubing to isolate them from each other and the metal plate.  I then etched the name and design in and plated the whole thing in nickel. I filled the etching in with some black paint. Underneath that is a steel plate to hold the magnets in place and (hopefully, maybe?) reflect the magnetic field up toward the strings. In between the loop and the steel is a piece of diffusion film to isolate the plate loop from the steel and dress things up a bit. The base is a piece of clear lexan. Overall thickness is almost exactly a quarter of an inch.

There are two 12 gauge copper wires soldered to each end of the plate loop which go into the box and are run around the core of a transformer from an old wall wart and are soldered together which completes the loop and brings the signal up to a low impedance, mic level signal.  From there, it gets wired to a TRS jack and I use a TRS to XLR cable out of the guitar.  At that point, you can plug directly into a mic input on a mixing board, audio interface or any other device that accepts a mic input.  If you want to go into a standard guitar amp you can, but you really want a mic to line impedance matching transformer for best results.

I have a couple videos I made a while back trying to show the basic idea with a loop of copper wire instead of the plate, but the concept is exactly the same:

https://youtu.be/jgCEzGvBElg

https://youtu.be/XH-rxzURxNo

The whole idea for this comes from this thread and a clever guy named Joe Rogowski who has been documenting his experiments for some years now:

http://music-electronics-forum.com/t5447/

Have fun and make cool stuff!

turtle