What is a PEtER Spline Filter? Digital audio ultimately comes down to one challenge: reconstructing a smooth analog waveform from discrete digital samples. The filter inside a DAC determines how that reconstruction happens—and how faithfully music is preserved in time.
Traditional digital filters force designers into compromises. Some prioritize frequency response, others phase accuracy or impulse behavior. Reduce ringing and another parameter often suffers. Many DACs address this by offering multiple filter options and leaving the listener to choose among them.
CH Precision took a different path.
The PEtER Spline Filter was developed to reconstruct the waveform with greater temporal integrity. By restoring the natural curvature between samples, it dramatically reduces pre- and post-ringing while maintaining accurate phase behavior.
This proprietary technology is used across all CH Precision DACs, forming a core part of the company’s digital architecture. When the time domain remains intact, the audible result is immediate: cleaner attacks, coherent harmonics, and a soundstage that holds its shape. Music emerges with a sense of natural flow rather than digital artifact.
