12/06/2014

1920s Harmony-made Supertone 2-Point Flatback Mandolin




These Harmony-made 2-point mandos are of course very cool but they have several design issues that mean that most of them have failed neck joints (or worse yet, collapsed necks bearing down into the top as this one had) and sagging tops near the bridge. This makes them unplayable even though the actual build quality of the materials is fairly good.

The upshot? When these are fixed up they're super and they look and feel flashy.



I worked on this for a customer and that work was heavier than usual: I reset the neck, replaced the fretboard, rebraced the upper bout to correct the usual neck-dive problems associated with this build, made a new nut, and then compensated and re-fit the original bridge and set it up with an extra-light (32w-9) set of strings.

The end result is a modern-feeling instrument with a great vintage sound that's actually quite similar to flatback Vegas of the time rather than what this originally would've sounded like: good, loud, but overly-warm and muddy on the treble.

There are reasons for the uprgade in sound: the neck joint is now nice and tight, the fretboard is a good thick rosewood one (= more stiffness in the neck), and I changed the scale length from 14" (which puts too much tension on the instrument's build and single-braced top) to 13 1/8" instead. This relocated the bridge higher up on the body and closer to the single brace that crosses the top below the soundhole. What this does for the sound is to clean it up, add a bit of punch, and make the instrument far more tuning-stable (as the old location, in a basically unbraced portion of the top, means the top sags under tension).

Decreasing the scale also lowers the tension added to the top quite a bit which means the instrument itself is under a lot less inefficient stress which is more conducive to producing better tone.


Rosewood-veneered headstock with bone nut.


I used almost-medium frets when fretting the new board and used some funkier abalone dots to sort-of simulate the mixed-color pearl that the original board had. I can't overestimate the difference new frets will make on an old instrument... especially on an old mandolin... where the original frets are often tiny.

Still, I probably wouldn't have replaced the board (and instead opted for an even lighter set of strings and my usual fret level/dress) if the board had not been entirely loose, mealy, and next to useless. For example, after deciding not to use it, I was able to snap the original board in half between two fingers (I was curious). This is due to the fact that Harmony often used maple fretboards that were "ebonized" for a black appearance. Over time the stain/dye eats up the board and makes it brittle.


It's a pretty instrument and I love the tortoise celluloid inset pickguard and the cool green/brown/yellow/black purfling.


The original bridge was still useful so I compensated it and fit it a bit better to the top (it was curved on the bottom from sagging into the old, less-braced location which is "ghosted" below it). It's made from ebonized maple with a bone saddle.

I should've mentioned earlier that I also had to reglue that said main-brace at one wing and glue up that pickguard/compression crack (small) on the top to the left of the pickguard's edge.


Nice tailpiece...



The mahogany back, sides and neck are all in good order and crack-free.


The recessed tuners work well after a lube and I also screwed them down into the headstock to improve tuning stability. Believe it or not but Harmony rarely ever screwed-down the tuners they "recessed" into their headstocks like this. Instead they're left shoved-into but free-floating in the routs for their backplates.

Why? I have no idea. Maybe they thought the strings would hold them tight in the slots or the coverplate would keep them from falling out or they were worried that the workers, being rushed, would pop the mounting screws right through the front of the headstock.

It's stupid, but both Harmony and several other makers chose not to mount their tuners correctly. Careful selection of very tiny screws and 5 minutes' worth of installing them would, I'm sure, have saved a zillion headaches with these instruments when they were fresh from the factory.


I didn't trust the sorta shabby joint even after a reglue so I "camouflage bolted" it as well. Convenient strap-hanger, too.






There's the Supertone label (sold through Sears).

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