The CV Calibration can be done through the SynthTool. Please ensure you are using the latest version found on the link below:
Once you are running the app, go to the Calibration tab on the left. You will see the screen below:
  1. Press START
  2. Connect a DC Voltmeter to TP1 and TP2 as per the diagram.
  3. Then, cycle through the 3 options (-2.5Vdc, 0Vdc, 6.5Vdc)
  4. Use DECREMENT and INCREMENT to adjust the voltage to match the selected value. COARSE will do larger intervals, while FINE will do smaller increments
  5. Once all values are set, press SAVE. The press EXIT and disconnect the voltmeter.