The effects of wax potting on pickup specs

[State of Epicicity]

I'm about to do an ambitious rewiring of my Schecter Sun Valley Super Shredder FR Exotic Black Limba, and one part of it is to replace the stock Schecter Sunset String bridge and Schecter Pasadena Classic Neck with Saphue Invader knock offs. These things are $20.00 for the set, so I’m not surprised that they don’t come wax potted. I thought I’d take some measurements before and after the wax to see if anything changed, and here’s what I found:

	Inductance	Resistance	Capacitance
Before
Neck:	4.20H	7.56K	-25.8nF
Bridge:	8.34H	14.81K	-13.73nF
After
Neck:	4.18H	7.51K	-26.0nF
Bridge:	8.26H	14.69K	-13.83nF

Now, the capacitance values of course don't make sense, but I’ve read that you have to measure a pickup’s capacitance with an LCR meter than will measure at 100kHz, which mine won’t. I thought it interesting though that there was a very slight change in any of these values at all. I just used standard paraffin Gulf Wax.

 

[Eagle]

I’m not surprised you get slightly varying results. I find if you measure the same pickup over different days you get a similar result.

 

[HomespunEffects]

How you get negative nanoFarrads?

 

[State of Epicicity]

I’m not surprised you get slightly varying results. I find if you measure the same pickup over different days you get a similar result.

Oh crazy! I had no idea. I'll have to try that with other pickups I have lying around.

 

[State of Epicicity]

How you get negative nanoFarrads?

You don't haha! I think that's the meter just going crazy. This thread talks more about the need for a meter that will measure at different frequencies:

https://guitarnuts2.proboards.com/thread/8271/measuring-pickups-capacitance-lcr-meter

 

[SillyOctpuss]

Oh crazy! I had no idea. I'll have to try that with other pickups I have lying around.

Temperature affects resistance too. If the ambient temp in the room is different from the last time you measured them you'll also get a different result.

 

[State of Epicicity]

Temperature affects resistance too. If the ambient temp in the room is different from the last time you measured them you'll also get a different result.

Oh cool; I didn't know that either. So it makes me wonder if the wax has any effect at all then.

 

[jay mitchell]

Oh cool; I didn't know that either. So it makes me wonder if the wax has any effect at all then.

Potting pickups makes them less microphonic. That's the entire motivation for doing so. Depending on the voltage your LCR meter applies to the pickup, it might (but probably won't) affect the inductance reading.