The original tuning instructions for the Bajack Capacitor seem to suggest there was no driver for the peizo. So if the device is constructed according to the plans, the peizo will only make a characteristic click noise during tuning. Of course no one ever follows directions. So we all substituted a peizo with a built in driver. And no one seems to be able to get the device to work. My suggestion is to forget the driver. Build the device according to instructions.