Abstract: This invention pertains to a fluorescent indicator adapted to indicate a level of a signal to be measured in an acoustic instrument and/or a vertical condition of a magnetic head in a multi-channel tape recorder.The fluorescent indicator comprises a fluorescent indicating tube having a plurality of segment anodes arranged in a row from a lowest level side to a highest level side, pulse generator means to generate clock pulses having the number of pulses corresponding to the level of a signal, and counter means including a plurality of output terminals connected to the respective segment anodes to have output signal sequentially generated corresponding to the count of the clock pulses to operate the segment anodes of the fluorescent indicating tube.

Abstract: This invention relates to a mode changing system for a cassette tape recorder in which operating members such as a head base plate and a pinch roller are selectively moved to one of various modes such as stopping, fast forwarding, rewinding, pausing, cueing and playing. This system comprises control means to control the movable components so as to move them to a position corresponding to a selected one of the modes. The control means is actuated by a control electric motor.

Abstract: This invention relates to a distortion factor meter circuit adapted to measure a harmonic distortion factor of a signal, particularly. A first transmission line is provided which is adapted to shape a first signal having a harmonic component to produce a DC signal, to convert the DC signal into a square wave having a width proportional to the level of the input DC signal and a predetermined periodicity, and thereafter to produce a triangular wave signal having a level linearly increasing from a zero level during the existence of the level of the input square wave signal and linearly decreasing immediately after the level of the square wave signal disappears. A second transmission line is also provided which is adapted to produce a second signal having a residual harmonic component left by eliminating a fundamental from the first signal.

Abstract: This invention relates to a control system for a tape recorder wherein magnetic head means is selectively moved relative to a magnetic tape. A recording and reproducing circuit including a recording amplifier and a reproducing amplifier is connected to the magnetic head means. Control means driven by a control electric motor moves the magnetic head means from a stopping mode to an operating mode including at least recording mode and reproducing mode. Mode selecting switches are provided to operate the control electric motor. The control system of the invention comprises means provided in the recording and reproducing circuit to energize it when instruction signals are received.

Abstract: This invention relates to a playback system for a magnetic tape recorder comprising an amplitude distortion corrector. It has an input versus output characteristic such that when the input level is less than the playback saturation level, which corresponds to the start of non-linear characteristics of the playback signal produced from a recorded signal at more than the recording saturation level due to a saturation of the magnetic tape, the output level is proportional to the input level. When the input level is more than the playback saturation level, the input verses output characteristics is complementary to the input versus output characteristic of the magnetic tape at corresponding signal levels.

Abstract: A level meter circuit for indicating a level of input signal over a wide dynamic range, comprising an amplifier of relatively high amplification factor having input terminal means to which an input signal is supplied and output terminal means to be connected to a level meter and negative feedback means including a feedback resistance to feedback an output signal from said output terminal means to said input terminal means, said negative feedback means characterized by further including non-linear impedance means connected in parallel to said feedback resistance and having such characteristics that when said output signal from said output terminal means is below a predetermined level said non-linear impedance means has a substantially infinite impedance and when said output signal from said output terminal means reaches said predetermined level said non-linear impedance means has a predetermined impedance.