KLOS A-Style

A carbon fiber mandolin with a familiar design delivers solid acoustic and amplified sounds.

December 11, 2025

With its astounding strength, light weight, and flexibility to take nearly any shape or form, carbon fiber composites have become the materials of choice for applications that require structural properties that go beyond traditional materials. A high strength-to-weight ratio is also a desired quality for building stringed instruments, and when you add incredible structural stability and virtual imperviousness to changes in temperature and humidity, carbon fiber is an attractive alternative to traditional wooden construction. Guitars that were made more or less completely out of carbon fiber started appearing in the 1990s, and today you can find a wide array of carbon-fiber guitars, violins, cellos, and other instruments. But there have been very few options for mandolin players who want to take advantage of carbon fiber’s benefits—a niche that Utah-based KLOS decided to fill. Founded in 2015, KLOS has become a major player in the carbon-fiber instrument world, offering a full range of acoustic and electric guitars, several ukuleles, replacement necks for electric guitars and basses, and—you guessed it—a mandolin. We recently had a chance to spend time with the KLOS A-Style mandolin, and I was especially happy to have Peghead Nation instructor and mandolinist extraordinaire Ethan Setiawan join me for this video demo.

While some carbon-fiber luthiers stretch their designs well beyond traditional templates, KLOS instruments tend to take a more traditional approach. And as its name indicates, the A-Style essentially follows specs of an A-5: teardrop body,f-holes, standard scale-length, familiar bridge and tailpiece. It’s made to feel and sound as close to a traditional A-Style mandolin as possible.

It’s clear that KLOS has a solid handle on working with the materials. For instance, while I’ve seen frayed edges of carbon-fiber cloth on other instruments, the KLOS is incredibly clean and precise throughout. The “composite ebony” fingerboard looks and feels like actual ebony, and it is home to a set of stainless steel frets that are closer in size to guitar frets than what is typically used on mandolins. KLOS chose a set of enclosed tuning machines, the instrument’s cast metal tailpiece has easy-to-reach string anchors, and the bridge itself is a traditional adjustable design made out of–wait for it–wood.

Our demo instrument included the KLOS EQ Preamp option. Consisting of a pair of transducers mounted inside the top and a preamp in the mandolin’s side, this system offers three-band EQ, volume control, a phase-reversal switch, and a built-in tuner. Output is via a standard ¼-inch jack, and the system is powered by a standard CR2032 battery that is easily accessible with a compartment next to the jack.

We had a chance to pass the KLOS A-Style around several players, and everyone came away with a positive impression. The instrument feels familiar and has a great setup, and its tone demonstrates that carbon fiber not only offers peace of mind when confronted with less-than-deal temperatures or humidity, it is also a highly resonant material. KLOS managed to voice the A-Style to deliver a traditional mandolin voice, with a bright chop, great single-note definition, and even balance throughout its range. Plugging the mandolin straight into a Fishman Loudbox Mini Charge yielded a capable amplified sound that could come in very handy in performance situations where using a microphone is impractical. As with most mandolin pickups, the sound would probably benefit from additional offboard processing.

In sum, the KLOS A-Style is a very cool instrument. Its main appeal lies in its ability to resist what might be considered abuse on a wooden instrument, but as Ethan Setiawan’s performance demonstrates, it also offers a mature tonality that sets itself apart from other A-Styles. The inclusion of the pickup makes it an ideal choice for taking it along to jams or festivals with unpredictable environments and amplification options, and top of everything else, few new mandolins will be as quick of a conversation starter than this one.

KLOS A-Style Mandolin