Try to add a small buzzer or speaker to the output (pin 9) via 220Ω to hear it. (or hook up your oscilloscope if you have one)
I still need to get a 4.7V Zener diode, so I'll probably just order some new pots too. I made a video of what I have built so far, but my internet provider (CenturyLink :@ ) decided to block youtube after my upload finished. I can't get the link to post here, but you can see it if you go to my firepinto channel. I'll link it here when I'm out of internet detention. :dodgy:
So far I have it scanning nothing.. but at least the LCD and LEDs are working. :cool:
If you do not connect the input to voltages over 5V there is no need for the zener. I have put it there just for the arduino safety in case the pickup coil feedback gives more voltage.
Just use a single potentiometer to 5V - pinA0 - GND. Give the highest voltage you will, and it will lock there.
Do the same for pin A1 to control gating frequency.
I would suggest to use a breadbord for your comfort, since the circuit needs more improvement
Nice video BTW.! Thanks for the feedback!!