yamaha-unit / yu
A musical interval measurement used by Yamaha on several of its popular electronic musical instruments, including its TG and SY series.
A yamaha-unit or yu is the logarithmic division of the 2:1 ratio octave into 210 = 1024 equal parts. It is calculated as the 1024th root of 2 (1024√2, or 2(1/1024) ), with a ratio of approximately 1:. It is an irrational number. The formula for calculating the yamaha-unit value of any ratio r is: yamaha-units = log10r * [1024 / log102] or yamaha-units = log2r * 1024.
A yamaha-unit is: