The guitar player for Duff McKagan’s Loaded, Mike Squires, brought his guitar over today with my Marshallheads in it.
The Marshallheads were a little squirrelly for his under high gain. He’s doing a show here in Seattle next weekend, and wanted to make sure it was good to go.
Before potting, I took a measurement of height adjustment and made a recording that displays a visual representation of the fundamental note, and all harmonic content.
After potting, I reinstalled, and adjusted exactly. Same strings were used. Same settings. Same everything, as close as possible.
The difference is striking.
What you see here is an open A string tuned 1/2 step flat (with moderate gain) You will see a frequency bar on the rigth hand side. The fundamental note is represented by the 4th line from the bottom, 415.30hz. Everything else is harmonics.
The brighter the line, the bolder and louder the signal. We can clearly see that many of the unpotted pickup’s harmonics are bolder, and sustain longer.
In the bottom image, the higher harmonic frequencies die off much quicker, and are much less present.
In the wax potted pickup, the two lowest harmonics are weak.
When a pickup is potted, we all know it reduces microphonics. The other thing that is reduced are the harmonics of those microphonics.. harmonic complexity.
No potting
Wax potted.
