As promised in the previous post here is some newer revisions of the amplifier board.
I have removed the guitar preamp and obviously the switch to control it as well. This makes the board a whole lot smaller so the overall footprint is now:
42.4mm * 22.5mm
I also have done a mono version, without the summing block. This removes 3 resistors and saves a bit more space. Not much, but it could be the difference between a fit or not! Mono version is now:
33.6mm * 22.5mm
Lastly I have done an all SMD version. This is more a test in ‘how small can it get’ but it should be functional. I havent tested it out yet. To make it even smaller I have deleted all component numbers. It might be possible to make it even smaller if the headers were replaced by SMD pads where wires could be soldered directly. the size for the SMD version is only
18.1mm * 20.8mm !
the SMD version also has stereo-to-mono summing so comparing the SMD and the PTH versions, the SMD version is only 40% of the original size. about 3.8 square cm!
WARNING! Since this is where the files are, chances are that you will read this warning as well! the linear regulator should be 3.3V and NOT 5V! The systems I’ve made is running on 5V but it is NOT recommended by the datasheet!