I'm on my second amp after the first sent a quiet/no signal to the left channel. This amp is doing the same. I've tried switching speakers and cables so its not that. Then I switched my power supply from an output of 12V 5A to 13.5 3A and the speakers wouldn't play anything/quiet. So now Im wondering if the voltage I am supplying is the issue? The amp is 20W and supports 4-8 Ohms. The speakers are 6 Ohms and have a 75W allowance. The speakers I am using are Phillips FWB-M530/17 and the amp is Lepei LP-2020A+. I would appreciate any advice/help