Series Pickup Resistance Calculator

While most of us spend time thinking about gauge and magnet selection for pickups, we don’t often consider what occurs once the signal pass them. A vintage-correct wound coil doesn’t matter much if you run it to an amp via a cable that sucks high frequencies or use incorrect pot values. Series wired pickups makes all this even more complicated because each additional coil provide increased output while also significantly increasing the inductance and capacitance drag. Knowing how these elements relate is difference between a clear articulate rhythm sound and a muddy mess that will bury itself in the mix.

The calculator above will do the math for you: How does your chosen combination of pots, coils and cables interact to change color of final signal? It does more than just show total DC resistance (which indicates how much electrical load the circuit put on the pickups). It also predicts resonant peak, which is where the pickup’s own inductance meets capacitance of the cable(s) and produces a naturaly boost of some frequencies over others.

How Series Wiring Changes Your Sound

Wire pickups in series, and you’re stacking up their resistances while adding together their inductances. Parallel-wired Telecaster neck and bridge sound twangy and bright; switch ’em into series and they has a thick, almost humbucker-like voice. The physics is simple enough: The more coils, the bigger the voltage potential, but it also means there’s a heavier electrical inertia created, rolling off the top end unless compensated for elsewhere in the circuit.

The other thing to remember is that DC resistance isn’t everything. It won’t tell you what your guitar will sound like underneath your fingertips. That’s where inductance comes in, the tool calculate this from your measured resistance and number of coil turns. Single coils has airiness thanks to their low inductance, whereas high output humbuckers is punchy and compressed due to higher inductance. If you want something weird, you can wire three pickups in series. Well, the inductance has tripled so it’s pulling resonant peak lower into the mids. Unless you short your cable or fiddle around with your volume pot, lowering amount of capacitance, you’re going to end up with a dark dull tone.

This is laid out on the page as a reference table showing how various pickup types react to these loads so you can understand why a vintage PAF needs 500k pots while a hot ceramic rail might choke with them.

Another common error among modders is assuming more resistance means louder volume. Yes, it will increase volume at first. However, if the combined impedance of your amp and all other pedals in your chain are higher than input impedance of your amplifier, you’ll start experiencing passive loading and will therefore lose signal strength. The calculator displays this as a percentage so you can actualy visualize the exact amount of voltage loss occurring prior to reaching your amplifier. So when you see this number getting too low, it may be time to switch out for a bigger pot value or move to a buffered pedal. It’s not a race to find largest numbers; it’s about maintaining enough signal quality in order to retain the character of the pickup.

One thing we tend to overlook when calculating inductors and capacitors are the effects of cable length. If you use a really long coiled cable, you’ll find all of that capacitance kills any high end clarity you may have had completely. Because of the increased inductance in the series wiring, the capacitor’s effects becomes even stronger. That short little patch cable might sound awesome on stage, but switch over to a twenty-foot cable while recording and it just won’t have the same bite anymore. With the ability to adjust the input for cable capacitance, the tool allows you to see what the translation will be between the practice room and studio before you go.

The bottom line is that series wiring is a game of balance: what do you want for output? What do you want retained in terms of frequencies? Remember, the entire idea behind adding coils are to trade brightness for power. Now understanding how those three elements; capacitance, inductance, and resistance. Interact turns your guesswork into engineering your sound. From modifying a vintage guitar to building a new bass, when you know why your rig sounds as it does, you make deliberate decisions instead of fortunate ones. You should of checked everything twice. And that same insight gained by testing out your pickups can be applied to the entire signal chain so that the voice you hear at home is the voice the audience hears on stage.