With its next machine, the TR-808, Roland aimed to develop a drum machine for the professional market, expecting that it would mainly be used to create demos. The concept was to build a "drum synthesizer" with which users could program drum sequences and edit parameters such as tuning, decay, and level. Though the engineers aimed to emulate real percussion, the prohibitive cost of memory drove them to design sound-generating hardware instead of using samples (prerecorded sounds). Kakehashi deliberately purchased faulty transistors that created the machine's distinctive "sizzling" sound. Chief engineer Makoto Muroi credited the design of the analog voice circuits to "Mr. Nakamura" and the software to "Mr. Matsuoka".