Ibanez SR505 5-String to 12-String Bass Conversion

Tommi Myöhänen's Ibanez SR505 5-String to 12-String Bass Conversion

Here's a quick rundown of my 12 string Ibanez SR505. I don't remember when I got the hankering for a twelve, though I do remember that Amy Humphrey's (Clatter) and Doug Pinnick's (King's X) playing had a significant role in that. I looked at different options on acquiring my own twelve and after much consideration I decided to find a suitable four or five string bass to be converted to twelve strings. I studied the different options for conversion and required parts from this very website and other online sources. After I asked guitar builder Jarkko Jokinen www.soitinrakentaja.com if he would be willing to take the project (he was) things started rolling.

Ibanez SR505 5-String

How it was made?

I started by buying a new Ibanez SR505 from a local music store. New because I wasn't patient enough to wait for a used one to show up for sale and I reasoned that I could sell the neck and other unnecessary bits once the conversion was done, to reduce the impact on my wallet. I also bought a Schaller 471 eight string bridge and Schaller BML Light tuners for the fundamental strings and Schaller Mini Locking tuners for octave strings. This is one of the things that could have been done better, as I'll explain later. For strings, I got sets from D'Addario and SIT, D'Addarios being currently on the bass.

I went with a five string as I found out that usual four string necks are not wide enough for the most commonly available Schaller bridge's string spacing. Average five string neck, on the other hand is just about perfect. If you are planning a similar conversion make sure that the pickups are bar magnet type, five string pickups with pole pieces probably wouldn't work too well.

Conversion itself was quite simple once we had worked out the details. Jarkko made a new neck and installed the bridge in place of the original Ibanez part and did the basic setup. Neck is maple, fingerboard, headstock veneer and laminated strip in the neck are an African wood called mwule, according to the builder. I don't know any finer details on that specific wood, other than it is very hard and fairly light. And light is generally a good thing when it comes to twelve string necks, as I'll explain later, again. Neck dimensions are basically the same as the original five string neck, except the new one is a lot thicker (22 mm at first fret, compared to 19.5 mm SR5 neck). Two truss rods, as that seems to be the preference for 12s.

Neck is exactly what you would expect from a custom builder, perfect in every way. There's some light flame figure in the maple but nothing too flashy, just perfect for a shy guy like me. The fingerboard wood matches quite nicely with the stock body and I quite like that little peek of maple at the neck root. Also, check out the mucho cool XII inlay action at 12th fret. Neck is attached with four screws, just as standard SRs. Now that I think of it, an extra screw or two would not have hurt anything though I haven't noticed any issues so far.

On the bridge side, Jarkko had to enlarge the bridge rout a bit toward the back to fit the new bridge and add some filler blocks to the sides. Fillers seem to be ebony although I'm not completely sure.

Would I have done something differently, knowing what I do now?

Only real problem so far is that when strapped on the bass settles to pretty much horizontal attitude. I prefer a more erect posture so I fixed that by adding a bag of lead shot to the backend of the strap. I'll have to figure out a more elegant balance solution later. It seems that the thin and light SR series body is not quite ideal for a twelve and it might be good to go to a thicker, heavier body, with more meat in the back. I guess Sir Mixalot was right, after all. One factor on the slight neck heaviness of course is the thicker than standard neck profile.

Another slight issue are the tuners. I got the Schaller BML light tuners because I wanted to keep the headstock as light as possible. However, the large diameter string posts do limit tuner placement to some degree so it might be better to go with thinner posted tuners for easier headstock packaging. I don't think the weight difference of four tuners is going to be that big of a deal.

Still, I'm happy with the result. Sure, the biggest limiting factor so far is my playing ability but as it goes with projects of this sort I had a few ideas for a new one even before this one was finished. I'll keep playing My Little Twelve for now and see what, if anything needs fixing. Once I have that figured that out it might be time for a new one.