6/10/2015

1923 Gibson MB-JR Banjo Mandolin




How great is this one? A customer sent this in for repair and it received a fret level/dress, new compensated rosewood bridge, some adjustments on how the wrist-rest/pickguard were seated, general setup, a new nut, tuner lube, and a new "adjustment bracket" for the aftermarket, bespoke "trap door" resonator that was added at some point. It plays spot-on, has a good, warm, but punctuated sound, and looks cool as heck.

The instrument appears to be a MB-JR model (mando-banjo junior), but I suppose it might be a low-level MB-#. At any rate, this never had a trap door resonator on it originally and it looks like the entire instrument has had an overspray at least (or refinish) and the headstock veneer is perhaps refinished (I usually see these with black finish all around). The factory order number suggests 1923 manufacture.


How do you like all those original/period features? The wrist-rest is especially cool (and functional) and the ivoroid pickguard is as well. This appears to have all-original parts save a couple hook/nuts and the added resonator. The original skin head is still holding up just fine (it's a 10 1/2" rim) so I've left it, too.


Oops, right, I replaced the nut, too. The one on it wasn't original and wasn't very well-fit, either.


The board is ebony with pearl dots. I strung this up with GHS A240 strings (32w-9), which I used standard on banjo-mandos. The (beefy) neck is nice and straight despite the long Gibson scale length (13 7/8").




The engraved tailpiece cover is very nice... and serves very well for foam muting to cut down on overtones.


My simple rosewood bridge emulates (after a fashion) wood-body Gibson mando bridges from the teens.



The repro (rosewood?!) trap-door style resonator is very cool.





Here it is wide open. Don't you love seeing a coordinator rod in a banjo? "Pull it out" to add height to your action, "push it in" to lower it. Simple as that, and very stable, too.


This didn't come with an adjuster mechanism for the trap door (it had a bungee on it to hold it tight!), so I rigged up this little friction-set unit from random parts in my banjo parts bin. The clip/bolt that come down from the resonator slip over one of the prongs on that U-shaped gizmo and the friction holds the resonator out wherever you want it. It works surprisingly well and didn't involve a lot of brain power, so I think the answer is that it's "good enough."

I used one of the extra holes "already provided" on the dowel to mount my silly U-clip.




Someone took a bite out of the rim to run a jack out of it! Yikes. Still, structurally happy...






The tailpiece is interesting in that it's not "mounted" to the rim at all. It simply slips over the tension hoop/flesh hoop bottom and stays put with string tension. It's kind of neat because it makes side/side adjustment really easy.

3 comments:

Amahl_Shukup said...

That one is mine! And I look forward to having it again for gigs and jam sessions. For such venues I usually play guitar and a standard, modern mandolin, but a banjo-mandolin is just the thing for getting that vintage sound on Old Time tunes, my latest favorite being "Dubuque." I just love the twonky banjo-mando sound on that one.

Uncle JimmyPie said...

" . . . standard, modern mandolin . . ." Nah, he brings these things to jams and glories in their oddness! Seriously, looking forward to hearing my friend play this old sweetheart again.

Amahl_Shukup said...

So OK, they're quirky... like me. :--)