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.

Common Myths of Scatterwinding

Myth 1. Scatterwinding is just a bunch of hype


Is good tone just hype?  Scatterwinding is putting the most space between each consecutive wind as possible, thereby lowering the capacitance of the pickup.  This is achieved by the winding pattern and the tension of the wire, which is usually done by hand, and takes years of experience.  This is, in my opinion, the most important aspect in pickup making next to resistance and magnetism.

scatterwinding a single coil


Myth 2. Scatterwinding can only be done by hand

Nope.  Although hand-guiding the wire onto the bobbin is probably the best and easiest way, you could get the same results from a machine.  I have heard that when Jason Lollar was starting out pickup winding, he made his own machine that would turn the bobbin and guide the wire automatically.  A pickup can be scatterwound in this way as long as the motion and wire tension are calibrated.  The problem is that machines are consistent and the point of scatterwinding is to be inconsistent, it is hard to replicate the motion of the human hand.

Myth 3. All handwound pickups are scatterwound

Not really.  The winding pattern and the tension are still dependent of a number of variables: machine type, speed, wire type, and most importantly, who is winding the pickup.  All will make a pickup sound different.

Myth 4. Scatterwinding just means randomly guiding the wire onto the bobbin

Wrong, it almost has more to do with wire tension, which takes a lot of time to perfect by hand.  If the pickup is too loose, you won’t get the correct number of turns and the pickup will sound thin.  Too tight and it will sound dead.  Here is a useful tool for figuring out the proper tension.

Myth 5. Scatterwound pickups need to be wax potted

Not always.  Microphonics are screeching sounds coming from winds of wire and little parts of the pickup vibrating together.  This can be a big problem when playing at a high volume on stage.  A lot of it has to do with the quality of the parts used, the age of the pickup, and how it was wound.  If you use a pickup that has been made with quality parts that fit together tightly and that has been carefully scatterwound, you do not need wax potting, and that gives your sound extra openness and clarity.  I have been testing this myself for years.

Myth 6. Single coils are scatterwound and humbuckers are not

Traditionally this is the case as most humbuckers are wound on a machine.  Personally, I prefer all pickups to be scatterwound.  Anywone who plays a with a humbucker in the neck position knows that it doesn’t really cut through the mix as well as the bridge in a band situation, try using a scatterwound humbucker!

’62 Strat pickup repair

This morning I had in my shop a bridge pickup from a 1962 Fender Stratocaster.  The pickup was not producing any sound when installed in the guitar and when hooked up to a mulitmeter, showed no resistance.  This means that there is an open circuit somewhere between the positive and the negative lead wires.  It is important to be very careful when working on this type of vintage gear in order to preserve the original tones of the guitar, so a number of steps were taken to carefully diagnose the source of the problem.

First, upon removing the cover I could see that this pickup uses Formvar wire, a common wire of the period, which gives it that coppery look.  There is a thin layer of wax on the pickup meaning it was at some point wax potted.

I could see that the wire leading to the black, negative wire is leading to the center of the bobbin and the wire leading to the white, positive, wire is coming from the outside.  This means that the wire was wound onto the pickup in a clockwise direction. If you point your finger at the left eyelet where the black lead wire is connected and then follow the wire on a path around the magnetized poles about 8,000 times and then end at the right eyelet you can see that this pickup was indeed wound in a clockwise direction.

When I oriented a magnetometer over the poles I could see that this pickup is South up with an average of 27 gauss.  A bit too much magnetism for a bridge pickup for my taste, but in the interest of preserving originality I left the magnets alone.

Next I inspected the condition of the actual Formvar wire and I could see that there was no visible damage.  My next step was to heat up the solder on the eyelets and add a little bit more solder.  This connection can get dirty over the years and cause a bad connection.

Eureka!!  After doing that I tested the resistance again and sure enough this pickup is reading about 5.44 thousand ohms of resistance, just right.  I am done and the original tone of the pickup is preserved.

If heating up the eyelets had not worked my next step would have been to disconnect the finish and unwind a few coils to try to find a break.  As a last resort I would have removed all of the old wire and solder, rewound the pickup with vintage-spec wire and waxed it.

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.