A Worthy Upgrade

Improved Tone with Just a Little Time, Money
By Will Kelly, Vintage Guitar® magazine

You are living in the golden age of guitar accessories. Every piece of guitar hardware has been thoroughly studied, analyzed, "improved" and marketed, and it can be a challenge wading through the hype to figure out what works (and helps), and what doesn't. Through my years of application and experience, I've come to recognize a couple of can't-miss upgrades that are worth the money, time and effort to implement.

I'm a huge advocate of quality electronic components. The majority of players who want to improve their guitars usually start by upgrading electronic components. These are usually easy to accomplish, mostly reversible mods that bring quick and tangible results. In my opinion, there is no better upgrade to a budget or mid-priced instrument than installing professional-grade switches, pots and jacks. These things do make a difference in tone as serviceability.

• Bourns is an American company that makes cool potentiometers. Those I use most are the Model 82 Vintage units, which are sealed, permanently lubricated and do not use carbon tracks to provide variable resistance. Rather, they have conductive plastic resistance tracks that do not wear out. They are noiseless and transparent-sounding. They do require different installation techniques, the major difference being in how they're grounded.

• For grounding connection, Bourns supplies a special metal compression washer with a lug tab. The threaded metal casing of the post does make great ground connections when used with metal mounting arrangements, such as an amplifier chassis, but the guitar modder will have to use this washer to ensure proper grounding. To install the Bourns on a typical Strat-style guitar, snap a quick picture of the wiring connections and label the wires with small pieces of masking tape. Then you can snip the wires from the terminals and ground casing, and remove the pots.

• If you have a guitar with mini pots, you'll probably find the Volume and tone control holes in the pickguard aren't large enough for a Bourns. Use a drill with a 3/8" bit to enlarge the hole to correct diameter. Install the Bourns with the special washer in place between the pickguard and the body of the control pot. In this instance we're replacing the master Volume pot, so I chose a 250k audio-taper control, which is the stock spec for this style of instrument.

• The terminals are in different positions than a traditional potentiometer, but there are still three and they perform the same function. On a master Volume control in a passive instrument, the end terminal is usually grounded so the audio can be rolled off. With Bourns pots, you'll have to solder a wire that connects to the grounding washer rather than simply bending the terminal lug and soldering it to a metal case. The other two terminals are wired in the traditional manner, with the input going in the end terminal, and the output coming out of the center lug.

• I solder a small-valve treble-bypass capacitor between the input and output terminals of a Volumen control, to bleed treble back into the signal as the control is turned down. However, I've found that I don't need to use additional resistor to adjust the taper of the pot, like I had to do with the carbon-track pots. The Bourns have an incredible consistent taper and smooth operation with no "play" or looseness.

  Tone controls in a Strat-style guitar are wired differently than Volume controls; the end-terminal lug is usually shunted to ground with a small capacitor. This provides carrying degrees of treble roll-off depending on the value of the capacitor. Most Strat-style, single-coil instruments use a .047-uF capacitor as a good match for the brighter-sounding single-coil transducers. Humbucker guitars more typically use .02-uF capacitors o better handle the thicker tone. Replacing these is basically the same as the Volume control.

• The shafts are configured with the standard splined/split ends that fit most plastic push-on knobs. Once the Bourns are installed, there's no aesthetic difference compared to the old setup. These controls are a great bang for the buck because they have a long maintenance-free life. The average guitar player will simply never wear them out. They sound transparent and have a great feel. They do cost a little more than traditional pots.

If you're unsure about the soldering and wiring, take the instrument to a pro repair shop. They'll be more than glad to install them for a reasonable bench charge. This is definitely one upgrade that's worth your money, time and effort.

Will Kelly is a guitarist, engineer, repairman, and collector who loves low-budget gear. His shop, Hard Knocks Guitar, in Cary, North Carolina, has played host to countless instruments and amplifiers.