| 摘要 |
PURPOSE:To record a musical tone, etc. so as to have a natural rhythm, by forming a feedback path of a sound recording amplifier system by a statistical operating circuit of a time integral system, and greatly expanding its applicable range. CONSTITUTION:A sound recording signal is superposed on a signal of a bias oscillator OSC through a voltage control type amplifier VCA forming a sound recording amplifier system RA and amplifiers A1, A2, and is supplied to a head RH. Also, a signal of the amplifier A1 is supplied to an absolute value amplifying circuit A3 constituting a statistical operating circuit of a time integral system, its output is supplied to an integral network I, a value of sigma basing on a normal distribution theory is calculated, and it is fed back to the voltage control type amplifier VCA through a memory circuit M. Accordingly, it is possible to automatically set to the largest value of a dynamic range basing on a normal distribution theory, unnatur recording caused by a sudden gain variation is removed, and the gain of the sound recording amplifier system RA is made variable automatically. |
