View Full Version : Tenor gtr conversion to octave

Sep-15-2008, 1:19pm
Hi, This may have been covered somewhere else, but I couldn't find it-so here gos- Is a Tenor archtop Guitar good for an OM conversion? Is the neck wide enough to convert to 8 strings? What about the tone? I've played regular teardrop shape OM'c but like the guitar shape.

Eddie Sheehy
Sep-15-2008, 1:32pm
I've seen Bouzoukis with the same nut width as a Tenor guitar. BTW, Soares Y' make an 8-string guitar-bodied instrument. I would think that because of the scale length and the size of the guitar body you would have to use heavier strings and would probably end up with a Mandocello - except that the nut would then need to be wider... Trial and error - have fun!

Sep-15-2008, 6:30pm
Do you have a particular tenor you plan on converting? If so, it would be helpful to hear some specs.

You can buy pre-made guitar shaped octave mandolins, if you want. Here's one:http://www.ellisguitars.com/OM_download.html

John Flynn
Sep-15-2008, 6:45pm
I think your bigger problem may be doubling the string tension on a neck that was designed for 4 strings. I looked into the possibility of converting a 6-string archtop to an OM and the luthier who built it said he was worried about the tension of just adding two more strings. I'm not saying it wouldn't work. In fact, I think it has been done successfully. I'm just saying I think the string tension might be the most important issue to look at and I'm not sure how you would know for sure.

Sep-15-2008, 7:32pm
I did it with a Harmony archtop tenor. I have posted the pictures some time ago in old posts in both the tenor section and the CBOM section. It came out pretty good, considering my lack of experience and limited tools.

*By far* the hardest step was redrilling the headstock cleanly and accurately for 4-on-a-plate mandolin tuners (after filling the original holes), with only a hand drill and no clamps or other setup to position the guitar and secure the headstock while drilling. It was not clean, and just barely accurate enough. The other thing to do is make and slot a new nut (I used a scrap of mahogany), and reslot the bridge saddle for 8 strings. Still, I would say this is a fairly manageable project for anyone who is interested in trying it, if you can get ahold of a tenor guitar inexpensively. I got mine for ~$100 so there wasn't much risk. I didn't find neck width to be a problem at the nut, which is 1-1/4", but the width doesn't taper out much up the neck, so it feels like the strings remain almost parallel. I'm sure there will be differences among different guitars. The tone is only OK; it is still an all-birch Harmony after all. It sounds best when strummed at light-medium volume, with open strings ringing as much as possible. Trying to "punch" out single notes doesn't sound too good. I would try it again, except that I would want a spruce-topped guitar, which are very rare to find in the cheaper Harmony/Kay/Regal family.

If the neck doesn't have truss rod, like on any old Harmony or Kay, the extra string tension could introduce some bend to the neck, but I haven't really seen much of that with mine. I use pretty light-wt strings, and also tune them down if I'm not playing the guitar on a regular basis.