Installing a bridge doctor on 1971 Martin D12-28 12-string guitar

I purchased a 1971 Martin D12-28 12-string guitar, knowing it needed some TLC. At minimum, the string action was just on the edge of being unreasonable.
Before doing a neck reset, I decided to give the JLD Bridge Doctor a chance. In this video, I show how to install the brass pin version, highlight some of the pros and cons, and ultimately decided that the more invasive neck reset is necessary.
#luthier
#martinguitars
#vintageguitar

[@HayesTech]

That's the first time I've seen that variant of the Bridge Dr. The one I'm familiar with has to have a hole drilled in the bridge, for a bolt and that model doesn't convert it to a pinless bridge. That's pretty cool. But as for what the Bridge Dr is used for, or designed to do, it is to reduce belly bulge. It wasn't designed to pull up the top ( the sound hole area). Sometimes that happens but not always. So it was designed to take care of belly bulge. Nice video though and nice to see there are different models to choose from now

[@Furtheronmusic]

I used one some years back on a Yamaha FG412 12 string. It helped a bit and at least stabalised the action. I used the one you drill in as I preferred leaving the stringing as normal.

[@johnmagee8195]

Nice demonstration. At 8:50, it looks like you put the rounded end up against the block. I think the rounded end is supposed to be inside the JLD block up against the tension screw (because that screw's end will them match the rounded point on the tension rod).

[@zwitchguitars]

Functionally, it hasn’t seemed to have mattered over this period of time. So maybe yes, maybe no 🤷‍♂️😅

[@chrislong5392]

Thanks, nice video. I'm looking at doing the same with a Höfner 12-string I just got. I'll probably have to use the brass pin version as there's not enough real estate to drill a hole in the bridge to accommodate the other Bridge Doctor model. I just wish that, aesthetically speaking, there was another option apart from brass. It really does change the look of the guitar a good bit, and as you found, the break angle too. Maybe if they offered it them in black. Also, it wasn't shown, but after trimming the dowel to length did you turn it around and insert the flat side against the end block? That seems to be the preferred method.

[@zwitchguitars]

Yes. The cut was clean enough to put it the other way, but it just seemed like the cut end should go inside the part hanging down and the factory edge of the dowel should go against the end block.

[@borgonianevolution]

Thats pretty neat how that bridge doctor works. I wonder if that forward pillar that puts the pressure on the top was more "T" shaped if it would put more even pressure across the under side of the bridge. Give the lower strings a bit more support.

[@zwitchguitars]

I think it might be the idea that you can put more pressure on a smaller area. But it suggested you use the D string slot…I wonder if using the A string slot would do what you’re talking about 🤔

[@borgonianevolution]

@@zwitchguitars I also wondered that but since this is my first time ever hearing or seeing this I didnt wanna sound dumber then I am hahaha

[@zwitchguitars]

Ha! Not dumb, that’s what the comments section is for 😅

[@zeferinocarrizales7940]

Good day, I was wondering what is the point of the bass pins, and if this would be a good idea to do on my twelve string. I play mexican regional and we double up the strings (no octaves) to give a heftier tone. Would this be a good idea for those who play this type of music or should I stick to a regular bridge doctor?

[@zwitchguitars]

This bridge doctor is one of the two choices, the reversible one. The brass pins keep you from having to drill a hole in the bridge. If you are doubling-up the bass strings, I do think having a bridge doctor installed is probably a good idea, as it would be a lot more tension. Either that or having thicker braces in the guitar to start with.

[@anthonykenny1320]

Good demo thanks but I didn’t get any brass string pins

[@zwitchguitars]

Thanks! There are two different kinds, one with brass pins and the other where you screw through the bridge. I’m guessing you have the latter.

[@petratical]

I am going to put a Bridge Doctor in my 1969 Red Lable 12 string guitar, and wonder if I could just drill a hole for the screw instead of using an existing pen hole, like you do for a 6 string. A Luthier told me to use a set of number 9 D'addario strings for old 12 string guitars.

[@zwitchguitars]

Yes, I believe you can. I got the pin version based on the recommendation at StewMac, but I don’t see why the screw method wouldn’t work as well.

[@petratical]

@@zwitchguitars Thanks for getting back. I forgot to mention my guitar is a Yamaha, made in Japan. Yeah, there are two different JLD's; JLD Bridge Doctor (for 12 string), and JLD Bridge System (for 6 string). I think you can do screw hole method, but really wonder why there is difference? Right, the brass pens do raise the strings just a little, but a little goes a long way in guitars!!!!

[@zwitchguitars]

@petratical The difference I think is some people aren’t comfortable drilling a hole in their guitar, or are unsure that the bridge doctor is the full solution.

[@dalesearcy5734]

I may be confused but if the low strings are buzzing now, couldn't you just install a taller saddle to get rid of the buzzing? Also why do you need to use all 6 brass pinless type pins? Couldn't you just use the one on the D string. I'm asking these questions because I have a friend that has a guitar in this same condition and the BD could be the answer. His guitar is a Dread Guild from the 70's.

[@zwitchguitars]

Hey Dale, thanks for checking out my video! The important part is *why* the string rattles. Usually a string rattle is because it hits the frets, and you’re right, raising the saddle would help. However, less frequently, the string can not have enough break angle over the bridge or the nut. In those cases, the rattle is irrespective of hitting the frets…and that’s what’s happening here. The brass pins don’t give enough break angle, which means that they buzz AND the action is still too high. Ultimately, I did remove the brass pins on the E and A strings to remove the buzz, but I still haven’t solved the string action issue. That will need a neck reset.

[@cugir321]

Why don't you use the one that you have to drill the bridge. You'll get your normal break angle and can slot the bridge if you need more angle.@@zwitchguitars

[@zwitchguitars]

@@cugir321the simple answer is, it’s not the one I bought 😂 Had the problem been completely resolved by the bridge doctor, then I might go ahead and do that. But since the neck has to be reset anyway, after that is done I might remove the bridge doctor altogether

[@anthonykenny1320]

But how do you mount the B string if the hole has the tensioning pin in it

[@zwitchguitars]

The pin has a hole parallel to the top where the string attaches, in a similar way to a top-mounted Strat/Tele bridge

[@anthonykenny1320]

@@zwitchguitars so the pin has to be sticking out

[@zwitchguitars]

@@anthonykenny1320 yes, the brass pin replaces the normal acoustic pin, and the string goes through the pin head instead of into the bridge

[@anthonykenny1320]

Jeepers what is 3 eighths if an inch

[@zwitchguitars]

9.5mm

[@coyotegrins]

...and it *still* needs a neck reset!

[@zwitchguitars]

Yup. Gotta try the easier thing before the more invasive one