Image 1
When doing aging work to the body and the neck of this guitar (which we'll cover in a later part of this series), it's important to remove everything from the guitar that's removable, so I took out all of the electronics. Taking a closer look at the removed guts, I found two metric standard (24 mm) sized pots from the Alpha company: a 500k linear pot for the volume and a 500k audio pot for tone with a 0.022 uF polyester film cap attached to it, all connected with plastic-coated shielded wire. I also found a small-sized budget output jack, connected with plastic-coated shielded wire.
The circuit of the guitar was wired in the typical "modern" style, and you can take a look at it on the website for Roswell, which is the company that makes the P-90 pickup on this guitar.
While the overall quality of the electronics isn't bad, there's still some headroom that could be added to enhance everything and put it a little closer to the vintage Les Paul Junior tone we're going for. To spruce up usability, here is my list of electronics and optional mods for tweaking this guitar. You can see a photo of the "guts" in Image 1.
I've known players who've gotten serious cuts on their hands from these. To avoid this, I prefer blunt-tip pointers with rounded tips and minimized risk.
1. Pots
Using two 500k pots follows the original formula of the Les Paul Junior, but using a linear volume pot in a passive guitar circuit doesn't make any sense. It should have two audio pots for much better usability, preferably with a 60:40 or at least 70:30 taper. In the last part of this series on aging the pickup, we discussed the stock pickup's treble response.
If you decide to keep the stock pickup like me, it's a good idea to use a mixed configuration with a 250k audio volume and 500k audio tone pot to get the best of both worlds. The 250k pot will smooth the high-end a little bit, and, as a positive side effect, the sweep control is much better compared to a 500k pot with the same taper—the nature of the passive beast. I decided to use two U.S. inch-measurement military-grade audio pots with a 60:40 taper: 250k for volume and 500k for tone.
To make these pots fit, you'll have to slightly enlarge the metric holes in the guitar. You can easily do this with a reamer or a simple half-round file. Because it's only a smidge, you should stay away from any other method! To minimize the risk of damaging the wood, don't use a drill press with a super sharp milling drill bit, etc.
2. Tone Caps
While 0.022 uF is the quasi-standard for single-coil pickups and the correct value if you want to stay as close as possible to a Les Paul Junior (0.02 uF), I decided to change the tone cap and convert the tone control into a warmth control—something we've covered in Mod Garage before. I decided to use a NOS military-grade 3300 pF paper-in-oil cap on this guitar, which will add some oomph to the tone. With the extremely low capacitance of the cap, it'll be possible to fine-tune the high-end and treble response of the pickup very precisely. If you want super dark jazzy tones, you should stay with the 0.022 uF value. This is a wide field to experiment with if you're inclined. Gibson also used paper-in-oil tone caps in their early Juniors—the famous Sprague "Black Beauty" caps.
3. Wire
While plastic-coated wire works, I decided to use the vintage stuff from the '50s, just like in the original guitars: cloth-covered wire.
The original vintage wire was AWG22 7-strand, tinned copper, consisting of seven individually tinned and twisted copper strands, with a woven Celanese overwrap, followed by a waxed cotton overbraid. Such wires are available as reissues from several companies. I also decided to skip the plastic-coated wire from the volume pot to the output jack, like in the original wiring, using shielded braided wire. The length of this wire is very short, so there's not much chance for hum and noise to creep in. If you want to stay as close as possible to the original, use cloth wire and shielded braided wire for connecting the output jack.
4. Output Jack and Wiring
The quality of the stock mini output jack is very decent, but upgrading it to a full-sized version is a good idea in terms of reliability and longevity.
The early Juniors were set up with '50s wiring, which is part of their special tone, and different from the modern-wiring style our Harley Benton came with. Because I will have to rewire everything already when I put this guitar back together, I decided to convert it to the traditional '50s wiring as shown in Fig. 1. This is also why I decided not to use an additional treble-bleed network on the volume pot. Usually, the treble response is perfect the way it is with traditional '50s wiring when rolling back the volume.
5. Knobs
Image 2
Using U.S. inch pots, the stock metric knobs will not fit anymore, so you'll need new knobs for the guitar. Taking a closer look at the stock knobs shows that Harley Benton uses the right and historically correct knobs (black "top hats" with bright numbers), but the size of the numbers is not correct (too big), and the printed numbers are pure white. The numbers on vintage guitar knobs usually turn a yellowish color over the years—something that's difficult (but not impossible) to mimic when you have knobs with pure white printing. So, I decided to get a new pair of knobs that fits U.S. inch pots and has the yellowish discolored embossed numbers in the correct size. You can clearly see the difference between the two knobs in Image 2. The stock knobs are made with modern plastics while the new knobs use vintage material from the '50s: fully tinted cellulose acetate butyrate (CAB for short). Besides the different look, the feel is also different to the touch.
6. Pointers
The guitar comes stock without any pointers, but, for a more vintage look, I decided to add them. Take care to get pointers with the right hole for your pots (metric or U.S. inch). Enlarging holes that are too small is not a fun project. Vintage correct are nickel pointers with 90-degree pointed arrowhead tips. Personally, I don't like the very sharp tips of these pointers because the risk of injury is high. I've known players who've gotten serious cuts on their hands from these. To avoid this, I prefer blunt-tip pointers with rounded tips and minimized risk to hurt you.
7. Jack Plate
Gibson used nitrate 3-ply (black/cream/black) jack plates on their early Juniors, while our Harley Benton guitar comes with a single-ply, solid-black jack plate. Initially, I wanted to swap the jack plate for a vintage-correct one, but while doing so I realized the Gibson jack plate won't fit the Harley Benton, which uses a smaller jack plate. Sure, it would be possible to make a custom jack plate out of the correct 3-ply material using the stock plate as a pattern, but I decided to simply leave the stock jack plate on the guitar, sacrificing some of the vintage look. Because I decided to upgrade the output jack to a full-sized version, I had to slightly enlarge the hole in the plate with a reamer. The four stock screws are chrome, so I decided to swap them for nickel versions, which will provide a more authentic look when aging them later.
8. Back Plate
Gibson used a black nitrate single-ply back plate in the '50s. Harley Benton did the same, but with modern plastic material. This is okay for me and will look very close to the original after aging it a bit. The two stock screws are chrome, so I decided to swap them for nickel versions for a more authentic look when aging them.
That's it for now. In the next part of this series, we'll cover the aging process for the hardware parts listed above and take a closer look at the pickguard.
Until then ... keep on modding!
Photo 1
To resume from the first part, please remember that the goal is to connect an individual part or piece in the circuit to ground, and the quality of a ground connection inside a passive circuit is not dominated by the gauge of the wire that's used. So, the more the merrier may look cool, but it's simply not necessary to overdo it here. Personally, I use a silver-plated, solid core AWG24 copper wire that looks nice and shiny and is also a joy to work with.
Let's start with version #1, the method that started it all: soldering the lug directly to the casing of the pot. This is the version Leo Fender used (remember: Leo didn't waste time on anything that wasn't necessary), but Gibson and all others used it as well. I like to call it the "cowboy version," or, for you Trekkies: This is the version James T. Kirk would have chosen when he would be into guitar-circuit soldering.
The handle of the cage is used to connect all three ground wires from the pickups individually, so it's easy to remove only one when you need to without adding any more heat to the case.
This is the most basic version and it's simply about bending the lug towards the casing of the pot and soldering both parts together as shown here in our example on a Stratocaster volume pot from 1965 (Photo 1). This sounds easy but it isn't. When you're not restoring a vintage guitar, I recommend using one of the other versions that follow. Depending on the pot, chances are good that you'll break the lug easily while attempting to make it touch the casing. This isn't the end of the world, but avoidable trouble.
Let's assume you managed to bend the lug towards the case without breaking it. You'll need a really hot soldering iron to connect both parts with each other, and soldering time will be a little bit longer than usual. The chance of overheating the pot is something to consider. With a good and quick soldering technique that comes with experience and the right tools, it's doable, but avoiding overheating is important to not kill your pot. If you're working on a vintage guitar, be very careful to not break the lug while bending it. Take care to clean both contact points and use a heatsink wherever possible. For more tips about soldering to pots, please read this column I wrote last year: "How to Install and Maintain Your Guitar's Pots."
Photo 2
Courtesy of singlecoil.com
All following versions are the "Gentleman versions," or, for the Trekkies out there: These are the versions Jean-Luc Picard would choose. Version #2 involves extending the ground wire. This is easy and neat to do when you're running a bare ground wire from pot to pot. Instead of soldering it directly to the case of the pot, run the wire though the lug of the pot you want to ground and solder it as shown here in a Stratocaster wiring example using a shielded output wire to the jack (Photo 2).
Photo 3
Courtesy of singlecoil.com
Version #3 is a kind of variation of version #2, using the grounded lug as the ground connection for the output jack, as shown here on a vintage-style Stratocaster wiring (Photo 3). Simply extend the ground wire for the output jack though the lug and solder it to the case and the lug, and you're done. I really like to use this version for a clean wiring, and as long as all pots are grounded this one works pretty awesome.
Version #4 is using a ground strap. When you're using a ground strap from pot to pot, you already must solder it to the case of the volume pot. Instead of heating up the case for a second time to connect the lug to ground, it's much more reasonable and easier to connect the lug to the ground strap. For this you have three choices:
1. Leave some slack on the ground strap so it touches the lug.
2. Bend the lug upwards so it touches the ground strap. Do not break it!
3. Solder a piece of wire to the lug and the other end to the ground strap.
Photo 4
Courtesy of singlecoil.com
In our example, shown in Photo 4, I used the slack method, so soldering was easy.
Photo 5
Courtesy of singlecoil.com
Now let's have a look at how to connect the ground wires of the pickups to ground, starting with the method Fender used right from the start on the Stratocaster: soldering all three wires side by side on the case (Photo 5).
Here you can clearly see: The lug is directly soldered to the case and the additional black wire you see is the ground wire from the output jack, so this case had to stand a lot of heat during the installation process. The advantage of this method is it's easy to change only one pickup if you need to by unsoldering only its individual ground wire. The disadvantage (besides the large amount of heat to the case) is that you need some practice to master this method because you must hold all three wires in place while soldering and usually need three hands for this (another one of those "alien tasks" in lutherie).
Photo 6
Courtesy of singlecoil.com
A really good alternative is to twist and solder all three ground wires together, so you only have one small soldering spot on the case (Photo 6). This is quick and easy to do, looks neat, and saves you some time, nerves, and exposed heat to the pot's case. You can also extend the twisted part to the lug you want to ground, similar to version #3 above, only the other way around. The disadvantage is that it's not so easy to change only one of the pickups if you need to. You'll have to unsolder all three ground wires, cut off the twisted part and pull out the wire you need.
Photo 7
Courtesy of Mark Foley/mfguitarproducts.com
In closing, I want to show you a really cool version that brings it all together that my friend Mark Foley, from MF Guitar Products in the U.K., is using.
Foley builds a kind of cage on the volume pots, connecting the lug with a piece of wire to another piece of wire (Photo 7). The intention and advantages are clear to see: Bending a lug downwards is much easier than upwards and the chance of breaking it is very minimal. Besides this, you only have two small soldering spots on the case that are quick and easy to do, saving a lot of heat on the case. So, what is the "handle" running across the case of the pot for? Is it only for connecting the wire coming from the lug? No, the best part is yet to come.
Photo 8
Courtesy of Mark Foley/mfguitarproducts.com
The handle of the cage is used to connect all three ground wires from the pickups individually, so it's easy to remove only one when you need to without adding any more heat to the case (Photo 8). It's also the perfect connection point for any other ground wires in the circuit, like the ground wire from the output jack, the string grounding wire coming from the tremolo claw, etc. And it's also a great guide for the hot wires from the pickups on their way to the pickup selector switch, so you don't need to use any additional tape, cable ties, or whatever else to bundle the wires. Is that a cool and clever solution, or what?
That's it for the topic of grounding. Next month we'll explore our next guitar mod, so stay tuned. Until then ... keep on modding!