Let’s build one of my favorite DIY guitar tools that I use daily in my shop. I’ll show you two versions and then explain how to put them into action.
Welcome back to Mod Garage. After receiving numerous requests to show more DIY tools for guitarists, today we’ll explore one of my favorites. For years I’ve used this one in the shop daily and I’m sure you’ll love it. It’s cheap and easy to build, but very effective for analyzing circuits of electric guitars and basses without opening the electronic compartment or lifting the pickguard. It’s a kind of adaptor or extension to measure a pickup’s DC resistance (DCR) from outside the guitar. After building one, we’ll discuss how to interpret the measurements.
The DCR of a pickup is by far the most common parameter you can read when reading pickup descriptions and often it’s used as an indicator of the output. The reason for this is that it’s easy to measure, but, sadly, it doesn’t tell us anything about a pickup’s output nor its tone. To quote pickup designer Bill Lawrence: “DC resistance tells you as much about a pickup’s tone and output as the shoe size tells you about a person’s intelligence.”
I’ve written about DCR as a pickup parameter in detail and you can read about it in “Mod Garage: Demystifying DCR.”
DCR is not a primary parameter in pickup design. It’s simply the result of the type and gauge of the pickup’s wire, the number of turns, and other parameters like the winding pattern, etc. But it isn’t completely useless, and we can use it as a good reference point for analyzing pickups both inside and outside a guitar or bass circuit. All you need for this is a digital multimeter (DMM). You don’t need an expensive calibrated precision DMM—any entry level DMM will work. You can get a simple digital DMM for $10, but if you want to invest in a better device, it can’t harm.
The easiest way to analyze a pickup is outside a circuit. Simply set your DMM to ohm and connect the two pickup leads to your DMM. If your DMM doesn’t have an auto-range function, set it to 20k ohm. Now you’ll get the DCR reading for your pickup. You can compare it to the factory specs of your pickup and it should be close. If your DMM shows “infinite” or “overload,” you know the pickup wire is broken. Let’s say your pickup should read 7k ohm, but yours reads around 2-3k ohm. Your pickup likely has a short circuit somewhere in the winding. Used this way, the DCR is always good to quickly check if a pickup is alive or not.
To quickly analyze a guitar or bass circuit with one or more pickups, you first need to build the DIY adaptor tool this column is about. There are two different versions, and you don’t need much for this:
- Version #1: This is the quick and dirty version. You need a standard 6.3 mm straight mono plug (the same type on all your guitar cables), some wire of your choice (preferably in two different colors), and two insulated alligator clips.
- Version #2: A more elegant version that you can also use with a scope if you have one. You need the same parts as for version #1, but instead of two alligator clips, you need two 4 mm banana plugs, and the two wires need to be longer than what you’d use for Version #1.
So, heat up your soldering iron and let’s get to building version #1.
- Solder one piece of wire to the HOT terminal of the mono plug and another one to the GROUND terminal. I prefer a red wire for the HOT and a black wire for the GROUND terminal (Photo 1).
- Solder an insulated alligator-clip to each end of the two wires, preferably a black one to the black wire and a red one to the red wire. Ready!
Version #2 is built the same way, but, instead of alligator clips, you solder a 4 mm banana plug to each end of the two wires, if possible, also in black and red. The two wires should be long enough that can place your DMM and/or scope at some distance from the guitar. In Photo 2, you can see version #1 on the top and version #2 on the bottom.
The difference between the two versions is that with version #1 you put the plug into the output jack of the guitar, connecting the two probes of your DMM to the alligator clips: the black probe of the DMM goes to ground (black wire) and the red probe goes to hot (red wire) as seen in Photo 3. With version #2, you need to remove the two probes from your DMM, plugging the two banana plugs directly into your DMM or your scope, also seen in Photo 3.
Both versions work equally well. Version #2 is just easier to operate when you also want to use the adaptor for a scope.
For a quick check, you can also directly touch the hot and ground terminals with the probes of your DMM, but you need both hands or a second person for this if you want to play around with the controls or the pickup-selector switch.
Now we can easily check four things with this tool, assuming everything is connected the way it should be and your DMM is set to ohm and auto-range or the 20k ohm scale if your DMM doesn’t have an auto-range mode:
- Do you receive a reading on your connected DMM? If not, check if the volume pot is fully opened. Do you receive a reading now? If so, close the volume pot completely and see if you still receive a reading. No? Perfect, you just proved that the volume pot is alive and well.
- With a fully opened volume pot and a reading on your DMM, slowly turn down the volume and watch the reading on the DMM. If you receive some crazy reading, chances are good there is a treble bleed network on your volume pot. If the reading slowly goes down to zero, you know that there is no treble bleed network on the volume pot, and you can check if it’s an audio or linear volume pot (plus the taper it has, if it’s an audio pot). Let’s say we have a 500k volume pot. When you close the volume pot halfway and receive a reading around 250k, you know it’s a linear pot. An audio pot, depending on its taper, will result in a much higher reading on the first 50 percent of the volume pot. If you read 500k until the volume pot is almost fully closed, this means the pot has a 90:10 audio taper—exactly the kind of volume pot you don’t want to have. If you read something around 300k in the middle of the volume pot, you know it’s a 60:40 audio taper.
- If the volume pot is fully opened and you don’t receive a reading on your DMM, chances are good that your output jack is broken, not connected, or connected incorrectly. Please make sure there is no activated kill-switch in the circuit that can also cause this “problem.”
- Turning the tone knob(s) will make no difference in the reading you receive. If you receive a slightly higher reading with a tone pot fully opened compared to when it’s closed, you know it’s a no-load tone pot.
There is a lot to discover from just the outside of any guitar or bass. So, now let’s see what we can measure from outside the instrument starting with a Telecaster with a 4-way switch. The readings in all examples are the readings I received with guitars I had in the shop, but they can be different in your instruments:
- Bridge pickup only: 5.85k ohm
- Neck pickup only: 6.76k ohm
- Both pickups together: 3.18k ohm
- Pickup selector switch in position #4: 12.30k ohm
The readings for both pickups are within the factory specs and are in a typical range for a vintage-flavored Telecaster pickup set. With a reading of 3.18k ohm for both pickups together, you know that both pickups are in parallel. With the reading of 12.30k ohm, you know that both pickups are in series with each other.
Here is the simplified math behind these readings:
- Series connection: DCR pickup #1 + DCR pickup #2
- In our example, it’s 5.85k + 6.76k = 12.61k ohm, which is very close to the reading of 12.30k we received. The missing 0.31k ohm are eaten up by the resistance of the pots and the tolerance of your DMM. For this test, I chose the cheapest DMM I could find in the shop. A calibrated high-quality DMM will have much less tolerance.
- Parallel connection: (DCR pickup #1 + DCR pickup #2) divided by four
- In our example, it’s 5.85k + 6.76k = 12.61k ohm divided by four = 3.15k ohm, which is very close to the reading of 3.18k ohm we received.
Now let’s repeat this with a standard Stratocaster:
- Bridge pickup only: 7.07k ohm
- Middle pickup only: 5.88k ohm
- Neck pickup only: 5.70k ohm
- Bridge + Middle pickups together: 3.26k ohm
- Neck + Middle pickups together: 2.94k ohm
All three pickups are within the factory specs of this Strat. We have a slightly hotter bridge and two vintage-flavored pickups. The two in-between positions are in parallel.
Lastly, let’s try a vintage PAF-loaded Les Paul:
- Bridge pickup only: 7.77k ohm
- Neck pickup only: 7.09k ohm
- Both pickups together: 3.74k ohm
Both PAFs have the typical vintage DCR and are in parallel in the middle position.
That’s it. Next month we’ll take a deeper look at changing wires on pickups, which is something I’ve been asked about a lot, so stay tuned!Until then … keep on modding!
by Dick Wacker – PREMIER GUITAR
Texas Republicans are pushing for a referendum to decide whether the state should secede from the U.S.
The demand for Texans to be allowed to vote on the issue in 2023 was one of many measures adopted in the Texas GOP’s party platform following last week’s state convention in Houston.
Under a section titled “State Sovereignty,” the platform states: “Pursuant to Article 1, Section 1, of the Texas Constitution, the federal government has impaired our right of local self-government. Therefore, federally mandated legislation that infringes upon the 10th Amendment rights of Texas should be ignored, opposed, refused, and nullified.
“Texas retains the right to secede from the United States, and the Texas Legislature should be called upon to pass a referendum consistent thereto.”
Texas Republicans are pushing for a referendum to see if the state should secede from the U.S. Above, Kenny Wolfam open carries a pistol and wears a “Trump 2020” t-shirt while counter-protesting a “Moms Demand Action” protest at Buffalo Bayou Park in Houston, Texas on June 17, 2021.
In another section on state governance, the platform states that Texas Republicans want the state Legislature to pass a bill in its next session “requiring a referendum in the 2023 general election for the people of Texas to determine whether or not the State of Texas should reassert its status as an independent nation.
The myth that Texas can secede from the U.S. continues because of the state’s history of independence, according to The Texas Tribune. Texas declared independence from Mexico in 1836 and spent nine years as its own nation before becoming a U.S. state. Texas then seceded from the Union in 1861 before being readmitted following the end of the Civil War in 1870.
The U.S. Constitution makes no provision for states to secede and in 1869, the Supreme Court ruled in Texas v. White that states cannot unilaterally secede from the Union.
“If there was any constitutional issue resolved by the Civil War, it is that there is no right to secede,” the late Justice Antonin Scalia once wrote.
Still, modern secessionist efforts have continued in the state for decades—and calls to secede tend to become louder when a Democrat is a president, according to the Tribune.
It’s not clear how popular the effort is among Texans, but the Texas Nationalist Movement’s website claims almost half a million Texans support its work to “make Texas an independent nation again.”
The movement’s efforts have been promoted by Texas Republicans. Last year, state Representative Kyle Biedermann introduced a bill that called for a “Texit” referendum, which was endorsed by Texas GOP chairman Allen West. The bill ultimately failed.
The bill was rebuked by lawmakers on both sides of the aisle, with Republican state Representative Jeff Leach branding it a “disgrace to the Lone Star State” and the “very definition of seditious.”
As well as the issue of a referendum, delegates also voted on more than 270 platform planks as the convention closed on Saturday. The votes will be tallied and certified in Austin, but it is rare for a plank to be rejected, party spokesperson James Wesolek told The Tribune. He has been contacted for additional comment.
Texas Republicans also approved a resolution declaring that President Joe Biden was “not legitimately elected,” signaling the continued support for former President’s baseless claims of widespread fraud in the 2020 presidential election.
The Texas GOP’s new party platform also called for full repeal of the Voting Rights Act of 1965.
Other planks also indicated a further shift to the right for the party, giving prominence to culture issues. The platform describes homosexuality as “an abnormal lifestyle choice,” and also declares that the party opposes “all efforts to validate transgender identity.
The platform also calls for a total ban on abortion and “equal protection for the Preborn.” Abortion is currently prohibited after around six weeks of pregnancy in Texas, but an imminent ruling from the U.S. Supreme Court could overturn the decision in Roe v. Wade that guaranteed abortion rights nationwide and trigger a law in Texas making abortion illegal.
The new Texas GOP platform also states that the education system should focus on “imparting essential academic knowledge, understanding why Texas and America are exceptional and have positively contributed to our world, and while doing so, also offer enrichment subjects that bless students’ lives.”
It calls for students to learn about the “Humanity of the Preborn Child,” including teaching that life begins at fertilization. It also demands that the state legislature pass a law prohibiting the teaching of “sex education, sexual health, or sexual choice or identity in any public school in any grade whatsoever.”