This is the link; http://www.amazon.com/gp/product/B00K67WI9I/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
It was a cheep one from china so I wouldn't be surprised if there was something wrong with it. The pulsation is in the form of a buzz in the speakers, it won't play music. The speakers are 8 ohms. I did not notice the heat sink getting hot and I did have it plugged in for several minutes. The pulses are the same volume despite where I had the volume knob. The output amperes of the power supply is 1 amp so I guess I made a mistake when calculating the requirements when I bought it, I thought I actually had some power to spare but I didn't think about how it would be providing the same amount of power to both speakers. I do have a 12 volt power supply rated for 5 amps so I don't ruin the one that I bought. Will 5 amps be enough?