Testing and troubleshooting the x0xb0x
What you need for testing
The bare minimum that you will need to test your x0xb0x is:
a multimeter (digital works best)
2 Double A batteries
aligator clips
High impedance (cheap) headphones
These items are nice to have when testing:
A multimeter with frequency detection, and 3 decimal places
A benchtop power supply capable of generating 2 Volts, 3 Volts and 12 Volts
These items are good for testing, but pricey:
Oscilloscope
Troubleshooting, a basic guide.
So you have soldered your x0xb0x and it doesn't work, now what?
Eliminate the obvious. Is it plugged in? Are all your chips properly seated in the sockets?
Check the polarity of the components. Is everything properly soldered? Check it agian. Remember: Electrolytic and Tantalum Caps, diodes, LEDs, transistors, and ICs all have polarity.
make sure there are no little bits of metal (espeically clipped leads) shorting out any connections. Also check through the resistors around the VCO and the sequencer. Some of them get pretty tight.
Perform the last test that you knew worked. Does it still work?
If you are having problems with the VCF, read through the VoltageControlledFilter section and get an idea of what it is doing. This will help you with troubleshooting imensely. Also, check out the relavent testing section for extra troubleshooting tips.