I found this 1W guitar amp design on the Internet:
And I am trying to build it on the protoboard. I could not find the IC TDA7052, instead I've got the a TDA7052B. According to the datasheet, the difference is that it has one extra pin for volume control (pin 4), which I connected to an 1M potentiometer, like this (and I am hoping that wire below is ground):
I am using a 12V DC input.
Now, I can't see the difference of what I have built and the schematics, but clearly there is something wrong. The speaker output on open circuit is about 12V when volume potentiometer is at maximum, with no input. First that I believe that the mean DC voltage should be around 0, otherwise it will have a constant current drain. Second that, according to my calculations, to have a 1W power output at the 8 Ohm speaker, the peak tension must be at most 4 / sqrt(2) = 2.83 V. At the measured 12V, the power would be much greater. Indeed, if I turn it on, the IC will quickly get too hot. If place 270 Ohm resistance between the speaker outputs, it will get too hot, instead.
Here it is:
For someone with more experience in analog electronics, it should be obvious what is wrong. Can you please help me?