Microphonic Minihums

seeker

seeker

New member
Supporter
Got an early 90s Gibson LP Special DC  that has a set of Gibson minihums taken out of an early 70s LP Deluxe.  Previous owner had the work done.

They sound really great, but once I get past any breakup and dive into distortion, they squeeel like a pig. 

Any solutions that don't involve wax potting? Would rather not go there.

Thanks!

 
take the covers off

Use a material that would insulate the cover and bobbin contact.

Tape

A little bit of melted wax.

thin strip of foam sponge material.

 
Ahhhh, so it's a physical resonance vibration thingy.

Thanks!

 
Last edited by a moderator:
yes.

Also,

They where potted along time ago at the factory, but the wax eventually evaporates or melts out in time.

But.... those lil soft clear plastic bobbins do not take high temps very well (150 degrees for 50/50 parifin, beeswax saturation).

a lower temp parifin will do for about another 40 years.

or candle wax dripped onto the warm inside cover, sealed quickly before cooling.

 
murkat said:
They where potted along time ago at the factory, but the wax eventually evaporates or melts out in time.
Click to expand...
Wow, had no idea.  Did they do the same with the T-top buckers?  Have one that also sounds great but with the same issue.  (It so does TSRtS-era Led Zep)

 
Last edited by a moderator:
murkat said:
But.... those lil soft clear plastic bobbins do not take high temps very well (150 degrees for 50/50 parifin, beeswax saturation).

a lower temp parifin will do for about another 40 years.
Click to expand...
How low? 

Found some that melts at 130 F.  After doing some reading, was amazed to learn that body temp "paraffin" is actually "petroleum jelly" (pure hydrocarbon, no additives).  You can tweak the paraffin melting point by adding in a bit of p jelly. 

 
murkat said:
yup.

I have potted my T-Tops in my 72' Custom with no side effects to tone at all.
Click to expand...
Yeah, I'm a firm disbeliever in the corksniffery that potting pickups changes them.  But I can hear the difference in a coiled vs. a straight cord!!! :ph34r:

 
seeker said:
How low? 
Click to expand...
I do not know.

Time to ask josh on this.

I do know that soft plastic bobbins, GIbson Clear bobbins, DiMarzios, will fold and melt. At what temp? I have never tried.

I do know that you need a temp of at least 145 @ least 20 minutes to saturate a coil for micro feedback.

 
Last edited by a moderator:
With those thin mini hb bobbins and butyrate hb bobbins, I pot at 140F.

Once the wax has melted to temp: cut a piece of paper and put that in the bottom of the wax pot so that your shiny cover doesn't get scratched up if it bumps the bottom. Submerge the pickup and agitate it by gently wiggling the pickup back and forth/up and down with the lead wire. 10 - 20 minutes should do the trick - or until no more air bubbles are streaming out. When you pull the pickup out, use a clean rag to wipe up excess wax off the exterior and then let the pickup cool down with the front of the pickup face down so that the excess wax inside will collect and harden where the cover meets the bobbins. Let it sit for 2 hours and you should be good to go!

 
Last edited by a moderator:
JGravelin said:
With those thin mini hb bobbins and butyrate hb bobbins, I pot at 140F.

Once the wax has melted to temp: cut a piece of paper and put that in the bottom of the wax pot so that your shiny cover doesn't get scratched up if it bumps the bottom. Submerge the pickup and agitate it by gently wiggling the pickup back and forth/up and down with the lead wire. 10 - 20 minutes should do the trick - or until no more air bubbles are streaming out. When you pull the pickup out, use a clean rag to wipe up excess wax off the exterior and then let the pickup cool down with the front of the pickup face down so that the excess wax inside will collect and harden where the cover meets the bobbins. Let it sit for 2 hours and you should be good to go!
Click to expand...
Ya, but could you be more specific?  :P  

 
You must log in or register to reply here.
Back
Top