Figure 3-16 is a low-noise preamplifier equalizing HA12017 consisting playback circuit, the circuit R3, R4 and C4, in line with standard maggots balanced network. The gain stag
e circuit 38 - 7dB (1kFk), the head output signal is a 65,7 Pi (1kH), pre-equalizer circuit output level of a 27dBo which for most standard input level of a 10dB power amp circuit is not enough, so there is need to add a voltage level of the amplifier stage 20dB amplification capability to fill the gap. Put this big stage can TL072, TL082 and NE5532 to serve O HA12017 applies not only to pre-equalizer circuit tape sound recording, but also applies to the electromagnetic RIAA phono pre-equalizer circuit. Then just change the RC network.