There is currently no such converter. Neither is there likely to be, due to the vast differences in their respective sound engines, and the fact that the new models have no onboard memory for storing the previous model's wave samples. Casio tone files (CKF, TN7, TON, etc.) contain only a sound's patch parameters. They do not contain the actual sounds (wave samples). The wave samples are hard coded into their host keyboard's system board. Tone files (patch parameters) from one model line will not work with the sound engine and wave samples of another model line, and there is no provision for getting the wave samples from the older model into the newer model. As a case in point, to my knowledge, the were never any converters from the much older CKF(Z05) tone files to the more recent TN7 tone files.