ArduiTape/CASDuino/TZXDuino - The cassette player replacements

Arduino Uno based Mark III. In a bid to make the overall dimensions smaller and also easier to build I have built the Mark III which is based on an Arduino Uno board, which is more expensive but a more reliable USB port and a built in DC power in port. The button board is still the same but there is a slight change in the design of the filter board. I may have left off one extra ground pin on the design. Because of how the Uno is built you can connect everything directly to the board using female to male dupont wires. I was lucky enough to have an Uno board with both male and female headers so I had even more flexibility. And heres the final build.  

VOLUME CONTROL Someone who is interested asked about volume control as some 8-bits are sensitive to volume of playback. I had thought about this originally, as I know from experience that the MSX can be tricky, but did nothing more other than to adjust the potentiometer on the amp before I placed the ArduiTape into its housing. However if you are using this on different computers this could be annoying so I've decided to modify the amp. If you want to do this you will need to get a 10k Ohm variable resistor/amp. Logarithmic is the best type for volume control but linear is cheaper. Also try to get a 3 pin mono as they fit best. This is the type I got for testing purposes. Desolder and remove the existing potentiometer, very carefully and add 3 single pins into the holes left behind. Once that is done take 3 dupont wires and remove the connectors off one end and solder the wires to the pins on the new potentiometer. Connect the wire from the middle p...