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I am a mandolin player who would like to play guitar. I tried 6 string and at my age I am not going to become very good at it and still keep my limited mandolin skills intact. The tenor guitar is tuned in 5ths, like a mandolin, and so I already know my way around it. But a typical tenor guitar is tuned CGDA and I'd like to have some low notes, too. There are a few 5 string tenors out there, but they are custom and expensive and take years to have built. I would like to try it before I commit to something like that.

To that end, I decided to try converting a 3/4 scale 6 string guitar to a 5 string tenor. (Typical tenor scale length runs around 21" to 23", but 23" really stretches the A string.) I have my eye on a Baby Taylor which I can get for very little money. My idea is to make a 5 string nut, take off that handy bolt-on neck, narrow it down to match the nut, and make a new bridge for it. I would probably just leave the 6th tuner in place, or I might remove it and put something in the hole. Doesn't matter at this point.

So my questions are about the bridge. If I take off the 6 hole bridge, fill the holes and drill 5 centered holes, they will fall right in between the original six. Even patched, the grain of the bridgeplate would not be intact and I'm afraid it would be severely weakened. Would doing this cause a nasty top failure? And what if I reinforced it with a Plate Mate?

Then I noticed that Breedlove and Greenfield, one a factory maker and the other a very good independent luthier, both use a pin-less bridge. The holes are drilled kind of like a classical guitar and have a recess at the rear so the ball ends don't stick out and look/feel ugly. (Here's a photo of one: https://smhttp-ssl-50735.nexcesscdn.net/images/resized/images/uploads/features/breedlove-distinctive-guitar-parts-anatomy-image-pinless-bridge_3000x900.jpg.)

If I were to make a bridge like this I could put it right over the existing holes and not have to drill new ones. That would really ease my mind about weakening the top and bridgeplate.

My question is, what effect will this type of bridge have on the sound?

Obviously I'm making a big change going from 6 strings EADGBE to 5 strings FCGDA and narrowing the neck to match. So I don't expect the new manifestation to sound identical to the old. But I'm not changing the top thickness or bracing or anything structural like that, so will having the strings pull at a very different angle totally ruin the sound? I know the notes will still play, but will I lose volume in going to this kind of bridge? Or tonal balance or anything like that?

Or maybe it will be an improvement? Why do some luthiers/factories use this type while most seem to use pin bridges?

Thanks, -Brian

Edit: BTW, if this does work out and I enjoy playing the modified Baby Taylor, I may either order a custom 5-string or make one myself. I'm pretty competent with tools and woodworking, I generally do everything for myself, and I have been interested in learning more about lutherie. I'm just not sure that starting out on an unusual instrument like this would result in an instrument that sounds any better than the modified BT.

I don't think it would have much of an impact on tone.

The force exerted by a pinless bridge are going to be different to a pinned one. I should think there could be a tendency to rip the bridge off the top. Although losing a string will reduce the total tension.

Dave

If you are handy with a router you could lower the pin area and glue and screw a slotted top cap on that would give some break angle at the saddle similar to what I do for travel guitars.
Another thing you might consider is adding strings instead of deleting them and make a "double tenor" guitar using the four center pin holes with angled string slots. You could cap the outside holes with pearl dots.

So that top cap is just added to an existing bridge? It does sound easier than making and replacing.


I actually did think about making the low string an Ff octave pair, but decided against it. Here is my reasoning for your critique:
Being tuned in 5ths rather than 4ths, some of the chords on a tenor guitar can involve quite a stretch. Keeping the neck as narrow as possible helps reduce this, at least somewhat. Adding the 5th string onto the usual four adds to the normal width of a tenor neck. Keeping the full 6 string width would probably make it unplayable for my average-length fingers. That's why I want to narrow the neck and fret board and that's one thing I like about the Baby Taylor: the neck can be unbolted so I can do this easily and hopefully all the way down to the bridge end of the board.

You could use the lower four holes and double the high strings and make the low string an octave pair. If you don't modify the neck you could always redo it as a 6 string.
I have built 5 course citterns. I found have having strings tuned to 5 different notes didn't seem to work as well as keeping it at four (FCGdg for example).
The bridge in the picture was made that way originally, but you could make a cap for an existing bridge in a similar fashion.

I want to narrow the neck as much as possible. My hands are not large enough to play a full width guitar neck in 5ths tuning with the longer stretches for some chords. It will be challenging enough with everything optimized. That's part of the reason for this whole experiment. Can I even play one?

Converting back to 6 string is not a priority. The guitar I'm looking at is a $200 one, used. I might even get it for a lower offer. I have the tools and materials I need to to do the conversion using your suggested piggyback bridge technique. Worst case I'd have to buy a bridge blank if I made my own from scratch. That's not a lot of money. If I do the best I can with the conversion and learn from the experiment, it will be worth $200 even if I cannot convert it back to 6 string in the future. And frankly if I do a good enough job, I can probably sell it for what I have into it. There is interest in 5-string tenor guitars among the small group of people who play tenors, but most people are in the same boat as I am: There are none available to try out and we are not willing to commit to the time and expense of ordering a custom built one if we have never played one before. Custom ones cost around $3000 or more and the waiting lists tend to be a year or two. I would be surprised if nobody was willing to spend only a couple hundred dollars for a functional one while they wait and then pass it on.