A sheet feeding device includes a drive unit that rotates a roll of a wound sheet in a first direction and in a second direction, a sensor having an output which changes according to a distance between a detecting position facing a peripheral surface of the roll and the peripheral surface of the roll, and a control unit that determines an amplification factor of the sensor on the basis of data. The data is acquired by changing the amplification factor while the roll is rotated once in the second direction and includes a plurality of the output value acquired at different rotation angles.

The utility model provides a compressor system with an equalizer (EQ). The compressor system includes a signal input device in signal communication with the EQ and a compressor. The compressor system further includes a signal output device in signal communication with the compressor. The compressor includes a signal detection module. In the system, an electrical level threshold of a full-band audio signal is setup in the compressor, and the value of electrical level of the input signal is detected by the signal detection module. After comparison of electrical level threshold and the value of electrical level, the system determines whether the compressor is activated or deactivated. The system can achieve the technology effect of effectively compressing and limiting the audio signal of a different frequency.

The utility model provides a compressor system with an equalizer (EQ). The compressor system includes a signal input device in signal communication with the EQ and a compressor. The compressor system further includes a signal output device in signal communication with the compressor. The compressor includes a signal detection module. In the system, an electrical level threshold of a full-band audio signal is setup in the compressor, and the value of electrical level of the input signal is detected by the signal detection module. After comparison of electrical level threshold and the value of electrical level, the system determines whether the compressor is activated or deactivated. The system can achieve the technology effect of effectively compressing and limiting the audio signal of a different frequency.

The utility model provides a compressor system with an equalizer (EQ). The compressor system includes a signal input device in signal communication with the EQ and a compressor. The compressor system further includes a signal output device in signal communication with the compressor. The compressor includes a signal detection module. In the system, an electrical level threshold of a full-band audio signal is setup in the compressor, and the value of electrical level of the input signal is detected by the signal detection module. After comparison of electrical level threshold and the value of electrical level, the system determines whether the compressor is activated or deactivated. The system can achieve the technology effect of effectively compressing and limiting the audio signal of a different frequency.

The utility model provides a compressor system with an equalizer (EQ). The compressor system includes a signal input device in signal communication with the EQ and a compressor. The compressor system further includes a signal output device in signal communication with the compressor. The compressor includes a signal detection module. In the system, an electrical level threshold of a full-band audio signal is setup in the compressor, and the value of electrical level of the input signal is detected by the signal detection module. After comparison of electrical level threshold and the value of electrical level, the system determines whether the compressor is activated or deactivated. The system can achieve the technology effect of effectively compressing and limiting the audio signal of a different frequency.