TZX Duino Amplifier for the ZX Spectrum +2

I have two working ZX Spectrum 2’s, the one I am going to have fun with is the one which I won for the outrageous price of £5 at auction in Aberdeen. The other I am going to keep as original; I tend to do this when I have two of the same computer or console. When I only have one computer or console I like to try and make my modifications fully reversible so that I can easily put them back to their original state should I wish in the future. I have a lot of plans for this Spekky and I think that this will be a multiple entry post. To start things off, I am going to modify the Spectrum so that I can use my own TZX Duino design to load software on the classic computer.