www.SimonDodd.org > Projects > "XS" double-neck


I love twelve-string electric, but given my general approach, it's hard to imagine a song that I might write or play on where all the guitar parts are twelve-string, where there is neither some heavier or funkier part nor a solo. For me, part of the purpose of building guitars is to get something tailored to my tastes, and part of it is to justify owning instruments that I could never justify buying; a double-neck is a perfect fit. So this is the project page for my double-neck build. My starting point is the classic Gibson® 1275 chassis, but I may end up changing it a little (along the lines of the Mark I HRT, which has a more aggressive lower cutaway than the classic tele silhouette) or a lot (I'm not wild about the SG shape).

709 masked out for spraying red 719 masked for blue 714 sprayed red IMG_0722 sprayed blue/red

Primary and alternative concept art. I don't know whether the Union Jack finish will stay in the mix; that won't be decided until painting begins. Is there some reason why 12/6 double-necks all-but invariably have the twelve on top? The only commercial exception that I know is the EBMM Axis, but I might naively think that for weight, balance, and playability, you'd want the twelve on the bottom. I would think that the lower neck would be harder to play, especially in terms of left-hand dexterity (less acutely the right), and for precisely that reason you would want the twelve lower if you expect to be playing chordal parts on the twelve and soloing on the six.

Three possible reasons for the prevailing practice spring to mind: Custom ("that's just how double-necks are built, ever since the 1275"), habit ("rock players wear their strap too long, they're used to having the cutaway for the six at waist height"), and access (could it be that having the twelve beneath the six would impede access to the upper frets, at least given the assumptions of the 1275 chassis?). So I'm flirting with the idea of reversing the necks.

The best arguments I have been given for the traditional approach are balance (reversing the necks will change it, but for good or ill? Hard to say) and the finger pressure one can bring to bear on the twelve neck. I don't know which way to come down yet, but, being a traditionalist, the deck is of course stacked.


Final concept art. I looked at many double-neck designs, even mocked up a few, and concluded that Gibson got it right from the get-go: For all its problems, the 1275 chassis is just more compact and more comfortable than anything else I tried. (Like the Mark I, there will be some finessing as we go, largely because I'm not wild about the SG shape.)

Two major departures from the 1275 spec, right out of the gate, are driven by playability on the 6 neck. The 1275 joins the neck at the 15th fret! The cutaway bottoms out between 17 and 18! That won't cut it. To improve this, I've done two things. I moved the bridge and rear pickup several fret-lengths closer to the front pickup, and experimented with several more aggressive lower cutaways, none of which looked right (because, I suppose, the eye naturally compares the upper cutaway), until I muttered a few exceptionally rude words and in exasperation just drew a slash across the paper, and… Well, presto, that kinda works. It’s asymmetrical, but it’s aggressive in a way that complements the upper cutaway, I think.

Consensus favored putting the 12 neck on top, for reasons of tradition and practicality. The 6 neck will have a ten-degree straight-pull headstock, and, like the Mark I, a 25” PRS scale length and an all-access neck joint; the 12 neck will have a 25.5” Fender® scale length, a head angle of about fourteen degrees (still mulling) and a more traditional Fender-style block heel. The plan is to build the neck in the same way that I built the Mark I neck, with two pieces of maple sandwiching a piece of mahogany. Maple fingerboards again. I’m still trying to decide between the traditional 6x6 head or the Ric arrangement.

Controls are a problem. The 1275 has a switch in the worst possible place, right where my forearm wants to sit when I play the 6 neck. So that’s gone; there’s a switch for the 12 neck where you’ve expect it on a Les Paul®, a switch for the 6 neck in the JPM position that I like, and a neck-selection switch between the two necks. Adding other controls would be awkward. I don’t think there’s any room for coil-tap switches, so likely no taps. (That only deepens my anxiety about pup choices. I may end up with Humbuckers from Hell®.) And the Bigsby® makes it hard to see how each neck can have its own volume/tone, which probably leaves master volume/tone as the only option, which is okay, but not optimal.

Routing control channels. I’m building the body out of plywood with mahogany tone blocks again. Ply is cheap, easy to work with, and paint can hide all manner of ugly. No, ply isn't a tonewood, but here's what I'd say about real tonewoods: Phooey. Fender built the original Telecasters® (Broadcasters) out of pine—and they didn't stop because the guitars sounded bad, or because the real luthiers at Gibson looked askance at the notion (Gibson's craftsmen were too busy being snooty about Fender qua an assembly-line outfit), but rather because pine isn't roadworthy. Indeed, the Vintage Vibe teles and strats issued by Fender's Squire® line a few years back are built from pine. They sound great.

And here's the dirty little secret: The best electric guitar model ever built, Gibson's ES33x series, is a plywood guitar. A new 335, a real USA-built Gibson ES335, can clear three grand—and it's a plywood guitar! So: So much for plywood as the peculiar preserve of cowboy outfits building cheap instruments.

But, and there's a big but, the 335 is built out of plywood with a maple central core. All of the guitar's guts are screwed into a nice solid chunk of real wood. EBMM is doing something similar in their recent Petrucci guitars. They build the basic chassis from basswood, to which they add a maple cap and a mahogany "tone block." (See this at about the 1:25 mark). That's precisely the operative principle that I used on the Mark I HRT, and it's what I'm doing on the XS. On the Mark I, I used a mahogany tone block because a tele is a very bright guitar and I figured that mahogany might tame the high-end. This one has humbuckers, so I'll use a maple tone block, figuring it might brighten it up. So in fact, although a lot of the body is made of ply, its guts, like the 335's, are going to be screwed into a nice solid chunk of real wood. So if I had to guess how the 6 neck will sound, it should be somewhere between an SG and a 335.


And the keel is layed down!
Vital internal component installation.
Glueing the body together.
Tone block installation.
Levelling the top.
Prototyping the headstock. This is another deliberate deviation from the 1275 spec: The lower set of tuners on the 12 neck and the uppser set of tuners on the 6 neck will be side-mounted rather than rear-mounted. If you've ever tried to tune a 1275, you know why. I don't always prototype, but in this case it seemed useful, and it does reveal an issue: The thickness required to side-mount tuners on the inward-facing sides of the headstock will oblige some careful routing to make the headstock thin enough for rear-mounted tuners on its outward-facing sides.
Spraying round one. I sprayed a few layers of primer, then filled any holes and gaps, sanded flat again, re-primed, sanded to 400, pencilled in the design, masked off the St. George's Cross and sprayed four layers of red, let it dry for a day, then masked off everything except the blue field and sprayed four layers of blue. Now the whole thing will sit for a week to dry good and thoroughly before the white coat.