Overview
Maker 'Koch' and model 'Chromatic' are clearly stamped on the metal cover plates and the original cardboard box. The instrument is a 10-hole chromatic harmonica in the key of C, as indicated by the 'C' stamp on the cover plate.
Identification
Vintage Koch 10-Hole Chromatic Harmonica Key of C with Original Box
Photo reference
3 uploaded photos
Story
Koch was a prominent German harmonica manufacturer founded in the 19th century, known for producing high-quality instruments. The company was acquired by industry giant Hohner in 1928, though the Koch brand name continued to be used for several decades. This specific model, featuring early 20th-century exhibition medals on the box, represents the classic era of German harmonica manufacturing.
Maker / Origin
Koch
Condition & Value
Cosmetically, the harmonica shows typical age-related wear, which is expected for a mid-century instrument. The original cardboard box is present but described as 'fair,' providing essential context and collector appeal despite its wear.
Full Research
See what it's actually worth.
Sold comps, value drivers, and venue guidance pulled from recent auction results.
Market Analysis
The secondary market for vintage harmonicas is niche but active, driven by players seeking specific vintage tones and collectors of early 20th-century instruments. Koch harmonicas, especially pre-Hohner or early Hohner-transition eras, hold historical interest but generally trade at accessible price points compared to flagship Hohner models. Items with original boxes move faster and command a premium, though buyers heavily discount untested instruments due to the high cost and effort of restoring reeds and valves.
Value Drivers
▲ Original cardboard box with historical exhibition medals significantly boosts collector appeal.
▲ Key of C is the most popular and versatile key for harmonicas, ensuring broader buyer interest.
▲ Clear maker and model stamps confirm authenticity and vintage German origin.
Concerns
▼ Untested playability — non-functioning reeds or stuck valves will drop the value to the 'parts/display' floor (~$10-$15).
▼ Unverified slide action — a stuck or bent chromatic button requires specialized repair.
▼ Unverified comb condition — hidden cracks or warping in the wooden comb would necessitate replacement.
Best Venue
List on a broad online marketplace like eBay or Reverb, where vintage instrument buyers actively search. Clearly state the untested nature of the instrument in the listing, but heavily highlight the inclusion of the original box with its historical graphics. A fast-sale price would be around $20-$25, while an optimistic list price of $50-$60 is reasonable if you are willing to wait for a collector seeking this specific boxed model. To maximize value, test the slide mechanism and gently test the reeds to confirm playability.
Upside Potential
If the harmonica is fully tested and confirmed to have a smooth slide action, intact windsavers (valves), and all reeds playing clearly in tune, the instrument could confidently realize the $50-$60 high end of the range.