Restored Koch (Hohner factory) button accordion in the keys of Bb/Eb circa 1935. This was made in Germany in the Hohner factory. It is in good condition overall. The embossed and varnished wood case is in good shape but shows normal wear for an instrument of this age. It has brown tape and yellow papers. The frames are nice blond wood and it has new closed cell foam gaskets. There is normal wear on the tape. It has 21 treble buttons and 8 bass buttons. The low buttons on each row of the treble side are the standard Hohner accidentals. The original treble, chord and bass reeds are steel on individual aluminum plates have the ‘H’ markings. The original leather one way valves were all removed and replaced with modern plastic one way valves for long trouble free life. All reedplates were removed, cleaned, one-way valves replaced and remounted and rewaxed onto the reedblocks. Bass valves have composite valves. Final tuning occurs in situ with the reedblocks inside the case.
The front grill cloth has been replaced. The wooden keyboard originally had broken and missing pieces between some of the buttons. I have added a custom designed and fabricated metal keytop. It features 21 elongated slots (not round holes). The slots and ends have been rounded over with a radiused cutter following the perimeter path of the slots providing a smooth to the touch surface for the fingers. This removable keytop allowed me to add button travel limiting so the buttons don’t disappear down into the holes as on standard Hohner instruments.
I have repadded the pallets on both the bass/chord and treble sides. This provides a quiet action and ensures excellent sealing. One treble block had a bow so I removed the felt bottom, sanded it flat and put a new felt bottom on it for a tight fit and no leaks.
I just added new gray cushions under the bass button tops. The bass strap and bellows straps are older but functional. The thumb loop has been flipped out of the way but can easily be put back if desired. I have added two new single shoulder strap brackets.
I also drilled some pressure relief holes in some of the highest note chambers to allow the notes to speak properly. I added a anti-resonance cross-bar between the treble blocks to minimize unwanted ‘wah wah’ effect.
Most of these older Hohner accordions are found with numerous notes out of tune, wheezing or not sounding at all. This was just fully tuned. There are 124 reeds in this instrument and every single one has been tuned. The treble reeds were tuned with a tremolo beat frequency of approximately 2 Hz at the low notes gradually rising to about 5 Hz at the high notes, for a sweet tremolo.