Converting a 5-String Bass to a 12-String

Adam Fogo from Ottawa, Ontario, Canada recently converted a 5-string bass into a 12-string! He has also converted a 4-string bass into an 8-string. Here are some photos of this cool custom 12 and Adam's description about how he made it work. Thanks Adam!

OLP MM3 5-string bass - Shown here in the Natural finish

Adam writes, "The bass started its existence as an OLP MM3 MusicMan copy 5-string bass. My aim was to incorporate the following elements: Lots of pearl, in the style of the Chandler Royale 12-string bass;  'Sting Ray 5 meets Music Man Sabre' vibe; and a 5-way switch and stereo outs for versatile sounds."

"My one concern was the greatly increased tension on the stock OLP neck. As a result I decided to tune the bass down one full tone, ddD ggG ccC ffF. The truss rod needed a small amount of tightening, but it is stable. I often drop the low Ds to C for C-G-C-F tuning."
 

The finished custom 12-string bass - Very Cool!

"The neck width at the nut is 1", which is 1/16" narrower than most 12-string basses. The bass is extremely comfortable to play (a huge change from my Galveston) and there is no neck dive."

"The electronics consist of a 3-band EQ / preamp borrowed from one of my 'real' Music Man StingRays. The pickups are Music Man copies from Custom Shop Parts in Florida. I painted the covers with white Krylon Fusion plastic paint."
 

"The pickups are offset a bit. The bridge pickup poles are centered under the fundamentals, the neck pickup poles are centered under the octaves. The bridge is a Schaller, ordered from Warmoth. The tuning machines also came from Warmoth."

"The bridge pickup is in the 'StingRay' position. I re-wound the coils to match the DC resistance of the real Music Man pickups. The neck pickup I arbitrarily placed halfway between the bridge pickup and the neck."

 

"My Grandfather made the maple plugs for the original headstock holes and drilled the holes for the new tuners. The brass nut was made for me by my uncle Alex. I covered the headstock with a piece of pearloid acetate from Constantine's in Florida."

 

"The bass has two outputs so I can run two amps. My basic setup has the bridge pickup running through the onboard preamp to a clean amp to get the 'StingRay sound'. The neck pickup runs directly out the second output to some sort of distorted amp. This routing is modified by the switch, which is a 5-way 'Super Switch' from Stewart-MacDonald. It operates as follows:

"Switch position 1 is closest to the bridge, 5 is closest to the neck -- coil 1 is the coil closest to the bridge, coil 4 is closest to the neck. The coils are connected in parallel. Any signal coming out of output 1 goes through the onboard preamp first."

"The sound I am going for with this bass is like Big Sugar's Garry Lowe and Gordie Johnson playing at the same time. However, I usually use it in mono with a completely clean sound for most of the artists I play with. The octave strings are quite harsh with just the 'StingRay' pickup. Switching coil 3 in mellows the sound significantly. All four coils together sound very smooth and bassy. Coils 3 and 4 together sound very P-bass like."

Thanks Adam!