Crane Song HEDD Quantum - Harmonically Enhanced Digital DeviceHEDD, acronym for Harmonically Enhanced Digital Device, has been engineered to provide musically pleasing sound with the capability of generating tube analog sounds within the digital domain. The HEDD QUANTUM has a new clocking crystal. It's Crane Song's 5th generation design, like the ones used in Avocet IIA and Solaris and has less then 1pS jitter. This results in extremely accurate imaging, a very open 3d sound and detailed transient response.