I called fisher about a month ago, my cz6 the plug in on the box where the coil wire connects is broken. They wanted $175 to do the upgrade to a cz6a, the unit has worked great ever since I owned it, the plastic just got brittle. I think $175 is a little much to unsolder some wires, and solder a new connector on both the earphone connector and the coil wire and connector on the box. From what I understand thats the upgrade, If thats the case I can do it myself, just need to find the connectors to do it with. Am I correct on what the upgrade is?