Photo 1—On this Ric’s original nut, string spacing between the pairs is inconsistent. Also, notice how the two strings in the 1st unison pair are closer together than in the 2nd unison. This nut will be replaced to improve playability. Photo by Andy Ellis.
Wrangling the RicIf you’ve played a 12-string, you know that typically the top two pairs are tuned in unison, while the lowest four pairs are tuned in octaves. On most 12-string guitars, the octave pairs are configured so each high octave string precedes its low octave mate when you strum down across the strings toward the floor.
But on a Rickenbacker 12, this convention is reversed. On string pairs 6-4, the low octave comes first, followed by the high octave, and this idiosyncratic stringing has a subtle sonic effect on chords and riffs. Rest assured the setup principles we’ll discuss here apply to any electric 12, regardless of which way the octave pairs are arranged. We mention the Ric stringing in case you haven’t yet had the pleasure of playing one—don’t freak out when you see it!
Typically the gauges for a light electric 12-string set are .046w/.026w, .036w/.018, .026w/.012, .017/.008, .013./013, and .010/.010, moving from the 6th to the 1st pairs. The “w” indicates a wound string, so as you can see, this means two of the octave pairs—the 5th and 4th—have a mix of wound and plain wire. As we’ll see in a moment, combining radically different string construction and thickness creates unique intonation challenges, and this applies to both electric and acoustic 12s.
Truss rod adjustment. Setups always start with a quick overview and then a truss rod adjustment, if needed. We want a little relief or “bow”—about a business card’s thickness— located around the 6th or 7th fret. As with all things guitar, there is no right or wrong, and while the laws of physics pertain to string rattle and intonation, personal preference ultimately rules. In general, the lighter your attack, the straighter the neck and the lower the action can be.
The Ric’s owner uses a regular light gauge set and plays with a light touch, so we checked the relief and tightened the dual truss rods slightly, reducing the amount of bow by a small amount. [For details on how to adjust a truss rod, read “Time for a Neck Adjustment?” and “Demystifying Truss Rod Tools.”]
String spacing at the nut. While initially inspecting our project Ric, we noticed that the strings weren’t correctly spaced at the nut (Photo 1), so we decided to cut a new one. To preserve the original look, we opted for black synthetic nut material.
Tip: It’s not uncommon to encounter oddball string spacing on an older 12-string, so be sure to check this when buying a used model.
When it comes to deciding on how to space the strings at the nut, 12-string guitars require extra thought: You have to deal with the space between the two strings within each pair, and, of course, the spacing of the pairs themselves across the fretboard. Remember, except for the two unisons, the strings are gauged very differently within each pair, and getting them to look good and feel right is more than twice as complicated as cutting a standard 6-string nut.
There are several different versions of “correct” nut spacing and, as with all things, it boils down to a personal choice based on feel. At our shop we use a computer-controlled Plek machine to cut nut slots because of its speed and accuracy. But machines have to be programmed by humans, so let’s look at the decisions we make when programming our Plek. By the way, these are the same decisions we’d make if we were doing this work by hand—the way we did for years before acquiring the Plek.
As with cutting a 6-string nut, our first step for this Ric was to place the outside strings—a .010 and the .046—where they feel best along the neck edges. The goal is to have these outer strings spaced as widely apart as possible for easy chording, but not so far out that they fall off the neck while playing. Where you place the outside strings depends on how the neck is shaped and how the fret ends are cut and beveled.
Next, we placed the inside unison 1st string where it feels good to fret, which is essentially as close to its mate as possible without causing the two to crash together when they’re plucked with a medium-hard attack. Many 12-string players will tell you that a certain amount of string-against-string “chatter” is actually part of what gives the 12-string guitar its unique chime, so you don’t have to completely eliminate this. A space between the unisons of about .070" is typical. That’s approximately the thickness of a quarter, which makes a great low-tech calibrator.
Now, using the Ric’s outside bass string (.046) and the inside treble (.010) as guides, we located the remaining “main” strings, in this case, the .013, .017, .026w, and .036w (the 2nd, 3rd, 4th, and 5th strings, respectively).
There are different formulas for spacing these main strings: equal center-to-center, equal space between strings, or a hybrid of these two approaches. Essentially, hybrid spacing uses equal distances from the closest edge of the smaller string to the center of the adjacent larger one, moving from the treble side toward the bass.
Before we had a Plek machine at our shop, we used a special formula to calculate our hybrid spacing. But now, there’s an easier way: You can use an inexpensive String Spacing Rule from Stewart-MacDonald to quickly do the job—no math required. [You can watch a video on how to use this tool at stewmac.com.]
Once you’ve located and marked the four main strings on the nut, it’s time to place each string’s pitch mate. Again, the first consideration is feel, although .070" is a good starting point for the space between each pair.