Here is a quote from the Esoteric website referring to the K-01XD SE:
"Finally, the SE version of the digital player models is now available with new discrete clock technology and improved analog circuitry in the DAC. We are proud of our brand and always strive for the best sound. The SE models we are releasing this time reflect every conceivable technological accumulation from the time the original model was launched to the present. Enjoy the enhanced presence, dynamics, and beautifully organic and musical textures of the new SE models."