This model is our first, and possible our most successful. This machine is named after the great English maker "Michael Hart". One of the great things about our "Hart" machine is that it is very easy to fit, looks good, works well and suits all styles of instruments. They were first designed by Gallery Strings for the purpose of converting four string instruments into five stringers. In the late 1970's players were very keen to get away from the C-string extension which can sometimes be noisy and somewhat out of tune. It was the development of the MK-1 "Hart" machine that gave us the idea of presenting a fine range of machines for players double basses. As you can see from the two pictures, the machine does not need to go completely through the peg box as the shape of the cog is sloped inwards, thus placing the worm and thumb screw will then hold the cog in place. The cog also has very low gearing, which gives a better chance for more accurate tuning.