1930s Gibson-made Kalamazoo KM-21 Archtop Mandolin

While these arched-top, A-style mandolins look a lot like Gibson A-50s, their tops are press-arched rather than carved and the necks lack truss rods. The latter isn't much of an issue as the necks are built just like teens-era Gibsons and I haven't met a warped one, yet. The former means that the sound is a little less popping on the highs and a little less distinct on the lows compared to a carved-top instrument, but as you can hear in the video clip -- we're not losing that much. This little item sounds great!

I worked on this for a customer and it only needed mild work, which was a nice change of pace. His other gear needed a lot more effort to get done-up. While this is clearly a 1930s instrument, there's no factory order number inside so I can't place the year exactly.

Work included: a fret level/dress, compensation added to the bridge, cleaning, side dots, and a restring.

Setup: action is bang-on at 1/16" at the 12th fret, strung with 36w-10 gauges. I wouldn't go with heavier strings than that on these guys, though.

Scale length: 13 7/8"
Nut width: 1 3/16"
String spacing at nut: 1"
String spacing at bridge: 1 5/8"
Body length: 13 1/2"
Lower bout width: 10"
Side depth at deepest: 1 3/4" + top/back arch
Top wood: solid spruce
Back/sides wood: solid mahogany
Neck wood: mahogany
Fretboard: rosewood
Bridge: rosewood, adjustable, compensated
Neck feel: medium V-shape, flat board

Condition notes: original except for a new strap button at the tailpiece and also crack-free throughout. The finish shows the usual weather-check and finish crackle, but looks good. There are a few light scuffs and scratches here and there, though.