PT2257 only gives me heavy buzzing sound I have this project where I control a bluetooth audio module with an arduino. In this case, I have used an arduino nano. But then, I have been meaning to add volume control to the project so I use a pt2257. But the sounds that it gives to me is my audio plus heavy buzzing sound and no matter how much attenuation that I set the volume doesnt seems to change. Can anyone help me?
Here is the schematics that I use for the PT2257:

I have tried giving Vdd 5V from arduino, and also 5V from a seperate power supply. But it seems there is no difference.
Here is the code that i use:
    void setup() {
      delay(1000);
      Wire.begin();
      Serial.begin(115200);
    }
    void loop() {
      Wire.beginTransmission(Volume_address);
      Wire.write(0b011100000);    // set low attenuation     
      Serial.print(&quot;result 1: &quot;);
      Serial.println(Wire.endTransmission());
      delay(2000);
      Wire.beginTransmission(Volume_address);
      Wire.write(0b11111111);  // set full attenuation           
      Serial.print(&quot;result 2: &quot;);
      Serial.println(Wire.endTransmission()); 
      delay(2000);
    }

Here is the link to PT2257 datasheet if you need it
EDIT:
Here is how I connect CSR8645 Output to my active speaker, before I add a attenuation IC. It works like a charm like this, but I need to add a volume control.
many amps and BT audio chips use differential input/outputs. none of the inputs nor outputs are considered grounds.
the Lp(left,postivie) Ln, Rp and Rn on your audio chip should be connected to loads directly. Ln or Rn are not audio grounds. so you can't use simple POT volume controls or any processor or amplifier chip that doesn't support differential IOs. so, you can't use PT2257 in this circuit.
for better understanding here are two audio signal types:

the simple, well known one, which consists of GND and an audio IN per channel. you can use many amplifiers, processors (e.h. PT2257) and POT volume controls. and one end of the output (e.g. speaker) is connected to GND.
the differntial audio signal which consists of a GND and a pair of IN+,IN- per channel. you can't use the soulutions mentioned above. for example, if you wanted to amplify the output signal of the bluetooth chip, you have to use something like PAM8302, 2.5W mono class D audio amp per channel. note the IOs: