Hi to all,
Just wondered if anyone can clarify something for me on the subject of earths in amplifiers?
I have just had my amp for the surround speakers on my tv pack in, so having a 9 pin amp IC handy I thought I would just make a new and smaller one, the surround is only used at low volumes usually and ther isn't much room behind the chairs where it lives, so I thought the stereo 11 watt amp would do fine.
After building the circuit on a small piece of veroboard, I hit a snag, the diagram refers to both power earth and signal earth, not having much experience with audio circuits this puzzled me!
I understand the need for the earths to be kept separate, but I don't understand where I should get a signal earth from! The 12v power supply I'm using provides me with an earth for the power side but how do I get an earth for the signal side of the amp?
I have attached the pdf file with the diagram I used (fig 6) and wondered if anyone can clarify things for me? EG which of the earths shown should go to the power supply earth and where to get a signal earth from so as to not get the dreaded hum!
Thanks in advance for looking.............Al