A high-fidelity pre- and post-amplifier 01

After practice by many audiophiles, we recommend the following high-fidelity pre- and post-amplifier.
    The preamplifier of this power amplifier is shown in Figure 5-117.
    I.M1894 is a non-complementary noise reduction integrated circuit composed of a dynamic noise reducer and a DC tone and volume controller. It can perform 10 decibel
noise reduction on ordinary tapes, VCD discs and FM broadcasts, so it is widely used. And the distortion is low and the circuit is simple.
    Because everyone has different music appreciation environments and different preferences for high and low sounds, the tone controller is
an essential part of the audio combination. The requirement for a high-fidelity audio tone controller is that it can change the frequency response to suit everyone's preferences, but
without compromising the sound quality. Therefore, it is recommended to use a single-chip DC tone volume control integrated circuit I.M1036. This integrated circuit has treble, bass,
volume , equal loudness, and balance adjustment functions 6. For the convenience of use, this circuit has designed equal loudness in the normally open state and balance. status
, no need to adjust. Since each control terminal uses DC voltage control and the potentiometer is not in the signal channel,
there is no need to use shielded wires to connect the circuit around the potentiometer. At the same time, the sliding noise of the potentiometer is eliminated. A single potentiometer can achieve two-
channel adjustment. It is possible to achieve high-fidelity adjustment without using expensive potentiometers , which is a unique feature for audiophiles to produce high-quality tone and volume control . -# Institution Strong versus Yuyin Bass##ii[★Gate Collection. ★Tone Bone★ When moving Xi, there is no boat. The common problem of the tone control circuit is harsh and soft, which is very beautiful. Installing this preamp on some amplifiers with colder and harder tone and poor high and low sounds can also have the effect of moving mountains and seas; this The low-frequency control of the tone controller is excellent, surpassing that of some subwoofer add-on boards.     When debugging the dynamic noise reducer, you can use a blank tape with no recorded program to play back to maximize the treble. The bass attenuation is minimal, and the volume is turned up enough to adjust the lkfl adjustable resistor between the ⑤ and ⑥ legs of I.M1894 so that the noise in the speaker is about to increase . It is best to repeat this step several times.