[frankheilig]

Not sure if this is the right place for this question but I just completed building a 4S preamp with volume pot on the input.  All works well except when pot is at zero.  Then a significant hum appears.  The hum is somewhat less when throwing the signal to ground.  Help please!

[Speedskater]

I think that you have a bad pot. the pot's wiper is losing contact at the zero position. Disconnect the wires and check it with an Ohm-meter.