The Yamaha TX81Z is a rack-mounted (keyboard-less) frequency modulation music synthesizer, which was released in 1986. Unlike previous FM synthesizers of the era, the TX81Z was the first to employ oscillator waveforms other than the sine, giving it its unique, grating timbre. The TX81Z has better digital-to-analog converters than many of its keyboard cousins, and has a reputation for producing more powerful bass sounds than similar vintage Yamaha synthesizers, such as the DX-11.