Lacquer Potting Pickups

Most modern guitar pickups are potted to prevent microphonics.  This can be done with wax or lacquer.  Wax is my preferred method for potting pickups as it is easier to work with and penetrates the coil better, but many vintage pickups from Fender and other brands are potted in lacquer.  Potting in wax also allows you to pot pickups with the cover attached, potting in lacquer should only be done with the cover removed.  By dipping a pickup in wax or lacquer and letting it dry, you are creating a hard casing that holds the individual parts and winds together.

I use a process incorporating lacquer and wax on my Fender-style exposed-pole pickups.  Potting the bobbins in Lacquer insulates the magnetic poles from the winds, this way a short is prevented if the coating on the winds is thin or starts to corrode.  Once the pickup is completed, it is dipped in wax to prevent microphonics.

Lacquer-potting bobbins is very simple.  Once the top, bottom, and polepieces are assembled, you can dip the bobbin in brushing lacquer from the hardware store and hang it to dry for 24 hours.  Once drying is complete you can wind it just like a normal pickup.

What is ‘scatter-winding’ anyway??

Many high-end pickup manufacturers like to boast (myself included) that their pickups are “scatter-wound,” but many people don’t really understand what this term means.  In fact the whole art of winding pickups is quite foreign to a lot of people, even if they play guitar.  Quite simply, scatter winding is a method of making pickups that results in a unique and beautiful sound.  In this post I’ll take a stab at trying to explain the principles of this method.

All electric guitar pickups use the same basic design, they are simply magnetic polepieces wrapped in very thin copper wire.  The polepieces generate a magnetic field that the string vibrates in, and the copper coils turn that vibration into an electric signal. 

In the ’50s, electric guitars started getting extremely popular.  Humbuckers, used primarily in Gibson guitars, used a uniform wind made on a machine; and single-coils, used primarily in Fender guitars, used a scatter-wound coil made by hand.  Technically you could use either method for either type of pickup, but it is widely believed that single-coils sound better scatter-wound.  Tension also matters when winding a pickup, looser winds typically sound clearer and better.

When I first started winding pickups I didn’t understand that the way in which you wind the pickups actually has an effect on the tone.  It made sense to me that the quality of wire you use, the number of turns, the quality of the magnets, and the strength of the magnets all played a part in the overall tone.  But I figured you would need some sort of ultra sensitive computer to hear if they were scatter-wound or not.  I made a couple of pickups by just guiding the wire back and fourth in a very even manner.  I made a couple variations of these and tested them, then I made a set of pickups using a scatter-winding technique.  The first thing I noticed was that the resistance (electrical output measured in ohms) of the pickup had dropped significantly.  When I installed them and tried them out I was amazed!  I was hearing details that I had never heard before, there was more treble and harmonics than I had heard from my earlier pickups.  The video below shows me scatter winding a pickup.  The wire is as thin as a human hair so you can’t really see it, but you can see how my hand is moving to get an idea of how it’s done.  It also helps to be blasting Pink Floyd while you’re doing this for 15-20 minutes per coil.

When coils are wound on a machine, each consecutive wind is very close to the last wind.  when you scatter-wind a pickup the idea is to put lots of space between each consecutive wind, this lowers the distributed capacitance of a pickup so that more treble and detail get through.  Your tone control on your guitar has a capacitor on it, as you turn that control counter-cockwise it uses more and more of that capacitor to bleed off highs to the ground, and the result is you hear a darker guitar tone.  Scatter-winding does just the opposite, it gives the pickup more treble.  This sounds really good on single coils because they have a very open sound to begin with, extreme highs and extreme lows, a lot of the guitar’s natural tone and character comes through.

When I’m scatter-winding a pickup, I try not to follow any sort of pattern and I move the wire randomly across the bobbin.  Machines are not good at this because they are programmed to do things very neatly.  I suppose you could program a robot to mimic the motion of the human hand, but that wouldn’t exactly be cost-effective.  The human hand is a really good tool for this because it’s hard for us to do things in a consecutive pattern.

Update 08/04/2010

You can also scatter-wind by simply guiding the wire back and fourth faster across the bobbin, thus putting more distance between each wind.

Scatter-wound pickups are more expensive because they have to be made by hand.  It also makes the pickup more unique because you can never exactly replicate what you did before, so each pickup has its own tonal character.  When Fender first started out as a company, all of their pickups were wound by hand, they are considered by many to be some of the best sounding pickups in the world.  Today they make thousands of guitars a year so naturally it doesn’t make sense for them to hand-wind each pickup, but there are a few other winders out there like myself who still hand-wind every single pickup.

Potting Pickups

Wikipedia defines microphonics as “phenomenon where certain components in electronic devices transform mechanical vibrations into an undesired electrical signal (noise).” The desired function of a guitar pickup is to turn the vibration of the strings into electrical signal. The pickup is basically magnetic pole pieces wrapped with thousands of coils of copper wire, if the copper wire or any other metal part in the pickup vibrates against itself it creates a screeching noise through the amplifier. Microphonics are not our friend, but they can be minimized by dipping the pickups in wax.

The process is fairly simple, but certain safety precautions have to be taken to avoid being burned by the hot wax or catching fire. Wax and the vapors it puts off are extremely flamable and should never be in the vacinity of open flame, that’s why you can’t melt the wax over your kitchen stove, and never try to heat it in the microwave. Use good ventilation.

The first thing you’ll need is a deep fryer designed for home use, these can be fairly inexpensive and all that is required is that it has an adjustable temperature setting. You will also need a thermometer that measures at least up to 150 degrees.

You will also need about a pound of canning paraffin wax and one-quarter pound of beeswax, you can find these at a hardware store or a hobby shop, call first though because this is not always something stores keep in stock.

Set your deep fryer to somewhere around 150 degrees (mine only has settings for 0-225-300-350-390, so I set it somewhere between 0 and 225 and watched the thermometer.) According to Lindy Fralin, a professional pickup winder, the mixture should be four parts paraffin to one part beeswax, so drop in one pound of paraffin and one-quarter pound beeswax.

When the wax is completely melted and the temperature is consistantly 150 degrees you can drop in the pickups, try to keep them from touching the bottom of the pot because that can be hotter than the wax, so put the pickup in the fryer basket or on top of a layer of marbles a the bottom of the pot.

Let the pickups set in the hot wax for about 10-20 minutes and pull them out. Set them somewhere to cool and when they are cool enough remove the excess wax with a soft cloth. They are ready to install and should play with very little noise.