Walkman bass boost circuit diagram

LAG665 and LAG668 are both single-chip player ICs. LAG668 is an improved version of LAG665, and the internal circuit structures of the two are roughly the same. For bass lovers, LAG668 can be used to replace the original LAG665, and the corresponding external circuits can be modified to achieve the improvement of bass effect. The measure for low-frequency enhancement is usually to attenuate high and medium frequencies. After the high and medium frequencies are attenuated, the signal is weakened at the same time, the excitation to the subsequent stage is reduced, affecting the audio sensitivity and dynamic effect, the volume is reduced, and the rated power output cannot be achieved. The remedial measures are: first, to increase the voltage gain of the previous stage; second, to increase the voltage amplification of the first stage; third, to increase the input impedance of the subsequent stage to improve the input sensitivity of the subsequent stage, so that a smaller excitation can meet the needs of the subsequent stage; fourth, to increase the gain of the power amplifier. LAG668 adopts the latter two measures. First, the input impedance of the post-stage (attenuator) is increased from 20k12 of LAG665 to 200kt2; second, the voltage gain of the power amplifier is increased from 28dB of LAG665 to 38dB. As shown in the figure, the bass boost circuit of the Walkman, the tone network of channel 1 is the same as that of channel 2.