you need to connect the ground pin at the preamplifier input to the minus on the board's power supply

Bro, cómo te puedo contactar? Atte. War :D

I ordered a preamp board,not the same as yours,it had a fake ne5532 chip,replaced the chip with a genuine one.

Use one single chip NE5532 or JRC4558 on the output side and on the input side do not use a chip just short the pins 1,2 and 6,7 on the chip base, that will make the noise go away.

Brother you need to replace DK125 with NE5532P and it will be ok. Mistakenly the manufacturer has inserted the wrong integrated circuit. Is it clear now ?

Entra é 12v até 24v Troca o ic 5532 liga ele em 20v ou 24v eu liguei na fonte de notebook 19v é funcionou meu tava assim

Voltagem está investindo tenho uma também não funciona só barulho 🤦🏻‍♂️

Muito ruído, péssima placa

DK125 is not a op-amp chip, it is for power supplies...they installed the wrong chips at factory. Get it refunded.

Ton conrolnya jelek dengung yg blm beli saran saya jgn beli ton ne 5532