Evolution of PCB for LM4780 based amplifier.

I had designed various PCBs for LM4780 based amplifier when I received 5 samples from National Semiconductor. I could get only Single-sided copper board in my market so I created the PCB single sided only.

This is the first one. I build this from scratch. Studying the pin details of LM4780 and I draw them on paper just as the basic schematic circuit is shown.

Little tuning of the PCB for thicker Power Supply tracks.

But it had a major constraint – 6 nos of jumper wires connecting the IC. I wanted to avoid that, so I redesigned the PCB. One very good thing I came to know about from DiyAudio was the use of n/c pins. So this was the All new third version. This came out to be most compact and straight layout. I made around 10 PCBs of this one.

This one is the latest. I tried to remove 2 more jumpers from V++ supply track and further thicken the power supply tracks. Mmm, still thinking to go for another version, little spacious this time. Troubleshooting become difficult in compact PCBs.