Gibson used a lot of Schaller machine heads, and the M-6 (Gibson part number part 82506) was one of the most widely used models, appearing on numerous SG, Les Paul and ES guitars. There were some variations over time, most notably in the shape of the button, the shape of the gear cover, the emblem on the cover (Gibson in this case) and the position of the screw tab. This typical seventies three-a-side set is shown mounted on a mid 1976 Gibson L-6S Custom electric guitar - attached with just one screw per machine head. The bushing and machine head assembly screw together from either side of the headstock; the assembly on the reverse, the bushing on the front, negating the need for screws to hold this unit down. The one screw pictured simply prevents rotational movement of the main assembly
One major advantage of tuning keys like the Schaller M6 is that you can easily disassemble them, and replace damaged or worn parts. The cog visible still within the body of the tuner is the part most likely to suffer from wear and cause tuning problems. This can be replaced by first removing the screw at the top end of the button, which allows the entire arm (to the right of the picture) to be removed. The cover (marked GIBSON) is very difficult to remove from above without damaging it. This is best removed by pushing with a small screwdriver or similar from the underside, now accessible thanks to the removal of the tuning arm.
The post holes drilled into the headstock of this L-6S have a diamter of mm.
List of Gibson guitar tuners
$1195
$69
$50
$150
$79
$995
$995
$795
$199
$1299
$79
$125
$199
$995
$400
$70
$200
$35
$70
$39