1.Project introduction

This circuit can adjust the audio input signal and uses the LA3600 chip to provide 5-segment circuit equalization.

Its center frequency and sensitivity are programmable
wide voltage input and can withstand 5-15V voltage without error output
high stability capacitive load

The frequency band can be changed through the capacitance from Base and NF to the total NF terminal, and the level can be changed by changing the potentiometer.

The capacitance and frequency provided by this circuit are as follows

Input method: Insert the 3.5mm cable into the input terminal, and use the DIP switch to select the channel (left and right channels). The output channel is also output to the 3.5mm cable. You also need to specify the channel.

Only supports single-channel input or dual-channel mixed into single-channel input. If you want dual-channel, you can use the debug pin, which is defined as follows

Pin and female headers are optional, 1*10p

Plug in the 9-18V power supply from the debug pin or power socket, plug it into the audio interface, and adjust the input and output channels to connect to the power amplifier.

2. Project attributes

This project is an original project and is being made public for the first time. It will only be made public on the Lichuang open source platform.
It is prohibited from being sold as a commodity under the GPL3.0 agreement and is only for learning, education and other purposes.

3. Open source agreement

This project complies with the GPL3.0 agreement and is not for commercial use. It is only used for learning and education. Secondary creation is allowed, but after the second creation, it must be open source under the same agreement.

4. Hardware part

Balanced IC

To make up for the audio shortcomings, LA3600 five-band equalizer chip is added, using DIP-16 package.
Its center frequency and sensitivity are programmable
wide voltage input, which can withstand 5-15 volts without error and output
high stability capacitive load.

This is its pin definition

Base is broken and a capacitor is connected in series to the nf terminal,
and then a capacitor is connected in series to the potentiometer to the total reference terminal
to achieve center frequency adjustment.

If you want to achieve more segments of adjustment, connect the output terminal of the upper stage LA3600 to the input terminal of the next stage, and adjust C1 and C2 to adjust different center frequencies.

Center frequency calculation formula:

5. Software part

This project has no peripheral software

6. BOM list

According to BOM list

7. Contest LOGO verification

There is Lichuang Mall’s logo on the front and back:

8. Demonstrate your project and record it as a video for uploading

See attachments and: [Demonstration video] 5 Bacteria-Breaking and Balancing Qi + Yin Xiang_bilibili_bilibili