Make sure that the STVC is set up correctly and the mic is connected properly.
Insert the microphone that came with the STVC into the XLR jack on the front board, until the connector clicks audibly.
Press and hold the Tweak button and press A to enter the System menu. Press Yes several times until you reach Input Gain. Use the encoder at the right hand side of the display to set the value to +15 DB.
Go to Mic Power by pressing Yes several times and set this value to ON.
Leave the menu by pressing Tweak again. Now go to any patch. Set the Balance knob to 100% Strings. Press the VOCODER button underneath the microphone connector, until the button is lit. The Freeze button must not be lit for this test!
Set the Main Volume knob to zero. Press and hold a key on the keyboard and talk into the microphone. Distance between you and the mic should be not more like 8″/20cm. Keep on talking, keep holding the key and slowly increase the Main Volume level. At some point, something should be audible over the line and headphone outputs.
If you have another mic at hand, please try this on the STVC as well. You can connect any dynamic microphone (for example: Shure SM58, Shure Beta 58A, Sennheiser e8xx series etc.) Please connect your dynamic mic with an XLR cable and test it. Condenser or ribbon microphones should not be used with the STVC though.